TRB Abstracts: Superpave and Hot Mix Asphalt Relatedspave/old/Technical Info/TRB/TRB... ·...

TRB Abstracts: Superpave and Hot Mix Asphalt Related 04-2160 New Zealand Experience with Foam Bitumen Stabilization TRB2004-000160.pdf 04-2187 Low-Temperature Failure Behavior of Bituminous Binders and Mixes. TRB2004-000187.pdf 04-2383 Statistical Comparison Between SHRP Aggregate Physical and Chemical Properties and an Asphalt Mixture’s Moisture Sensitivity TRB2004-000383.pdf 04-2459 On the Essential and Plastic Works of Ductile Fracture in Asphalt Binders TRB2004-000459.pdf 04-2466 A Model for Predicting Damage Evolution in Heterogeneous Viscoelastic Asphaltic Mixtures TRB2004-000466.pdf 04-2548 Implications of Experimental Measurements and Analyses of Internal Structure of HMA TRB2004-000548.pdf 04-2559 Modulated Differential Scanning Calorimetry of SBS and its Blends with Bitumen TRB2004-000559.pdf 04-2577 Effect of the Newly Developed Cellulose Oil Palm Fiber in the Fatigue Cracking of Stone Mastic Asphalt TRB2004-000577.pdf 04-2607 Initial Validation of a New Surface Performance-Graded (SPG) Binder Specification TRB2004-000607.pdf 04-2616 Comparison of Performance and Cost Between Superpave and Conventional Hot-Mix Asphalt in Washington State TRB2004-000616.pdf 04-2623 Effect of Moisture Damage on Material Properties and Fracture Resistance of Asphalt Mixtures TRB2004-000623.pdf 04-2658 Modeling the Behavior of an Idealized Asphalt Mixture Using the Distinct Element Method TRB2004-000658.pdf 04-2688 The Effect of Material Transfer Devices on Flexible Pavement Smoothness TRB2004-000688.pdf 04-2735 Evaluation of the Dynamic Angle Validator (DAV) TRB2004-000735.pdf 04-2744 Performance of Cold in Place Recycling in Nevada TRB2004-000744.pdf 04-2863 Prediction of Seasonal Variation of the Asphalt Concrete Modulus Using LTPP Data TRB2004-000863.pdf 04-2900 Evaluation of Use of Synthetic Lightweight Aggregate (SLA) in Hot Mix Asphalt TRB2004-000900.pdf 04-2925 Workability of Hot Mix Asphalt TRB2004-000925.pdf 04-3000 Field and Laboratory Performance of Superpave Mixtures in Nevada TRB2004-001000.pdf 04-3081 Using a Single Test to Determine Specific Gravity and Absorption of Aggregate Blends TRB2004-001081.pdf 04-3094 Oxidation and Hardening Kinetics of the Rheological Function G'/( ⎜'/G') in Asphalts TRB2004-001094.pdf 04-3096 Effect of Superpave Defined Restricted Zone on Hot Mix Asphalt Performance TRB2004-001096.pdf 04-3112 A Comparison of Falling-Head and Constant-Head Techniques for Estimating Field Permeability of HMA Pavements TRB2004-001112.pdf 04-3159 Study of Fatigue Cracking Mechanisms in Asphalt Pavements Using the Viscoelastic Continuum Damage Finite Element Program TRB2004-001159.pdf 04-3168 Twenty Years Later - Experience with Cold In-Place Recycling as a Reflective Crack Control Technique TRB2004-001168.pdf 04-3200 Analysis of Temperature Data for the NCAT Test Track TRB2004-001200.pdf 04-3250 Practical Use of Emperical and Fundamental Rheological Relationships for the Purpose of Specification of Polymer Modified Bitumen TRB2004-001250.pdf 04-3255 Open Synthetic Wearing Course TRB2004-001255.pdf 04-3275 Field and Laboratory Investigation of Permeable Asphalt Mixes on Georgia Highways TRB2004-001275.pdf 04-3338 Aggregate Orientation and Segregation in Laboratory Compacted Asphalt Samples TRB2004-001338.pdf 04-3346 Lab Study on Degradation of Stone Matrix Asphalt (SMA) Mixtures TRB2004-001346.pdf 04-3359 Prediction of Thermal Cracking Behavior of Asphalt Concrete Using the Viscoelastoplastic Continuum Damage Model TRB2004-001359.pdf 04-3420 Road Map for Mitigating National Moisture Sensitivity Concerns in Hot Mix Pavements TRB2004-001420.pdf 04-3431 The Use of a Performance-Based Fracture Criterion for the Evaluation of Moisture Susceptibility in Hot Mix Asphalt TRB2004-001431.pdf 04-3436 A Multi-Layer Boundary Element Method for the Evaluation of Top-Down Cracking in Hot Mix Asphalt Pavements TRB2004-001436.pdf 04-3441 Effects of One-Way and Two-Way Directional Heavy Vehicle Simulator Loading on Rutting in Hot Mix Asphalt Pavements TRB2004-001441.pdf 04-3455 Effects of Asphalt Aging on Hot-Mix Asphalt Dielectric Constant TRB2004-001455.pdf 04-3458 Pavement Surface Friction Testing Using the Standard Smooth Tire; The Indiana Experience TRB2004-001458.pdf 04-3494 Why Do We Need to Change G*/sin δ and How? TRB2004-001494.pdf 04-3502 Analysis of Multivariate Models to Evaluate Segregation in Hot-Mix Asphalt Pavements TRB2004-001502.pdf 04-3506 Evaluation of Simple Performance Tests on HMA Mixtures from the South Central United States TRB2004-001506.pdf 04-3670 Strong But Flexible Foundation for Chisago County TRB2004-001670.pdf 04-3715 Identification of Hot Mix Asphalt Permanent Deformation Parameters Using Triaxial Strength Tests and a Microstructure-Based Viscoplastic Continuum Model TRB2004-001715.pdf

04-3741 Verification of VCA Testing to Determine Stone-On-Stone Contact of HMA Mixtures TRB2004-001741.pdf 04-3747 Field Validation Study of Low-Temperature Performance Grading Tests for Asphalt Binders TRB2004-001747.pdf 04-3748 Evaluation of the Moisture Sensitivity of Bituminous Mixtures Using Complex Modulus ApproachTRB2004-001748.pdf 04-3775 Characterization of Polymer and Fiber-Modified Porous Asphalt Mixtures TRB2004-001775.pdf 04-3811 Accelerated Pavement Testing Evaluation of the Structural Contribution of Full-Depth Reclamation Material When Stabilized with Foamed Asphalt TRB2004-001811.pdf 04-3824 The Effect of Different Axle Configurations on the Fatigue Life of an Asphalt Concrete Mixture TRB2004-001824.pdf 04-3827 Detecting and Measuring Hot-Mix Asphalt Segregation Using High-Speed Texture Measurement TRB2004-001827.pdf 04-3942 Determining Air Voids Content of Compacted SMA Mixtures TRB2004-001942.pdf 04-3974 Role of Modified Binders in Rheology and Damage Resistance Behavior of Asphalt Mixtures TRB2004-001974.pdf 04-4077 Mechanical Properties of Asphalt Mixtures Using Recycled Tire Rubber Produced in Brazil A Laboratory Evaluation TRB2004-002077.pdf 04-4088 Laboratory Study of Fatigue Characteristics of HMA Surface Mixtures Containing RAP TRB2004-002088.pdf 04-4092 Effect of Aging on Asphalt Concrete Moisture Damage TRB2004-002092.pdf 04-4287 Evaluating the Performance of Modified Asphalt Binders with Identical High-Temperatures PG’s but Varied Polymer Chemistries TRB2004-002287.pdf 04-4374 A New Criterion for Superpave High Temperature Binder Specification TRB2004-002374.pdf 04-4377 Modeling Permanent Deformation Using Laboratory, Proto-Type, and In-Service Accelerated Pavement Testing TRB2004-002377.pdf 04-4393 Accelerated Moisture Susceptibility Testing of Hot Mix Asphalt (HMA) Mixes TRB2004-002393.pdf 04-4397 Innovation of Compaction Techniques for HMA TRB2004-002397.pdf 04-4423 Results of Simple Performance Tests and Environmental Conditioning System Integration Efforts TRB2004-002423.pdf 04-4456 Harmonized Resilient Modulus Test Method for Unbound Pavement Materials TRB2004-002456.pdf 04-4490 Comparison of Field and Laboratory Permeability of HMA Mixtures TRB2004-002490.pdf 04-4507 Rheological Properties of Asphalt Mixtures Containing Recycled Asphalt Pavement (RAP) TRB2004-002507.pdf 04-4509 Upgraded TTI Overlay Tester: A Simple Reflective Cracking Simulation Test TRB2004-002509.pdf 04-4511 Novel High Performance Composites for Hot Mix Asphalt Applications TRB2004-002511.pdf 04-4530 NCSU Wheel Tracking Device: Its Ability to Predict Rutting of Superpave Mixtures TRB2004-002530.pdf 04-4631 Evaluation of Modified German Rotating Flask TRB2004-002631.pdf 04-4704 Aggregate Shape Classification System Using AIMS TRB2004-002704.pdf 04-4725 Variability of Air Voids and Mechanistic Properties of Plant Produced Asphalt Mixtures TRB2004-002725.pdf 04-4734 Can Chemical Modification of Paving Asphalt be Equated to Polymer Modification? A Laboratory Study TRB2004-002734.pdf 04-4752 FWD Spatial and Temporal Variability Within and Between Pavement Sections of the Virginia Smart Road TRB2004-002752.pdf 04-4782 Ruggedness Evaluation of the Dynamic Angle Validation (DAV) Kit for Superpave Gyratory Compactors TRB2004-002782.pdf 04-4798 A Nine Year Evaluation of Field Cracking and Rutting Performance of SPS-9 Experiment TRB2004-002798.pdf 04-4811 Gamma-Ray Spectrometric Method for Determining Bulk Specific Gravity of Cylindrical Hot-Mix Asphalt Concrete Specimens TRB2004-002811.pdf 04-4814 An Analysis of Three Methods of Sampling Hot Mix Asphalt from Behind a Paver TRB2004-002814.pdf 04-4816 Measurement of the Acoustical and Mechanical Properties of Porous Road Surfaces and Tire/Road Noise TRB2004-002816.pdf 04-4854 Evaluation of Non-Nuclear Density Measurement Devices for Determination of In-Place Pavement Density TRB2004-002854.pdf 04-4869 The Role of Bending Beam Rheometer Parameters in Thermal Stress Calculations TRB2004-002869.pdf 04-4884 Laboratory Evaluation of Engineering CIR Emulsion and Foamed Asphalt Mixtures for Cold-In-Place Recycling of Asphalt Pavements TRB2004-002884.pdf 04-4938 Laboratory Performance Testing of OGFC Mixtures TRB2004-002938.pdf 04-4992 Dynamic Modulus Testing of Asphalt Concrete in Indirect Tension Mode TRB2004-002992.pdf 04-5136 Material Characteristics of Asphalt Rubber Mixtures TRB2004-003136.pdf 04-5179 Highway Preventive Maintenance Implementation: Comparing Challenges, Processes, and Solutions in Three States TRB2004-003179.pdf 04-5180 Reduced Confined Dynamic Modulus Testing Protocol for Asphalt Mixtures TRB2004-003180.pdf 04-5196 Evaluation of New Test Methods for Determining the Bulk Specific Gravity of Fine Aggregates Using Automated Methods TRB2004-003196.pdf

New Zealand Experience with Foam Bitumen Stabilization

by

Mofreh F. Saleh

Assistant Professor University of Canterbury

Department of Civil Engineering

Prepared as a part of an investigation conducted at University of Canterbury and funded by Transfund New Zealand

Submitted for Presentation at the 2004 Annual TRB Meeting and for Publication

in the TRB Record Series

October 2003

TRB 2004 Annual Meeting CD-ROM Paper revised from original submittal.

New Zealand Experience with Foam Bitumen Stabilization

Abstract

Foamed bitumen stabilization is burgeoning steadfastly internationally. Although it involves higher initial material costs than cement or lime stabilization, it offers the advantages of being free from transverse shrinkage cracking and in the speed of the technique that minimizes traffic delays. The work forms part of a larger project aimed at investigating the feasibility and potential applications of the foamed bitumen stabilization technique in order to speed up its adoption in New Zealand. In this research, the foaming characteristics of two sources each of two grades of bitumen currently in use in New Zealand are presented. The effect of bitumen source, grade, and the type of fines were studied. Fly ash type C was used to modify the aggregate gradation to adjust the percentage of the fine fraction (passing 75 µm sieve). Portland cement was used at 2% by the dry weight of aggregates as a partial replacement of the fly ash. The foamability results of each source were quite different. For each source, the softer grade provided better quality foam than the harder grade. Two groups of mixes were prepared. The two groups were identical except that the first group contained 2% cement as a partial replacement of the fly ash. The optimum foam and water contents were determined for the two groups. The effect of curing time on the resilient modulus of foam stabilized mixes were investigated. Both groups showed high resilient modulus values and rapid rate of increase of the moduli with curing time. Also using cement as a partial replacement of the fly ash provided significant improvement to the resilient modulus values and speed up the rate of strength gaining. Introduction Although foamed bitumen stabilization is gaining wide acceptance in several countries around the world, it has not been practiced in New Zealand. A major advantage of foamed bitumen stabilization is that the pavement can carry traffic immediately after compaction. Although the strength of the mix increases over a period of months as moisture evaporates, the curing rate is more rapid than that of emulsion mixes. Another major advantage of foamed bitumen stabilization process is that it does not have any particular adverse environmental impacts. The stabilization process does not involve the emission of volatiles, such as in cutback stabilization, or corrosive dust when using lime or cement stabilization, which is particularly important in urban areas. Foamed bitumen stabilization requires less energy compared to hot mix asphalt because of the ability to mix the aggregate wet and cold without the need of drying or heating it up. Adding a small amount of water or steam (about 2%) to hot bitumen results in the formation of a foam that expands many times the original volume of the bitumen (1,2). The low viscosity of the foam allows it to mix easily with aggregates. The foam breaks and preferentially coats the fine aggregate particles in the mix. Foamed bitumen mixes are distinctive in that, as opposed to hot mix and emulsion mixes; large aggregate particles are only partially coated. The bitumen coated fines form a mortar that binds the mixture together.


Olard, Di Benedetto, Eckmann, Vaniscote - 2 -

Low-temperature failure behavior of bituminous binders and mixes

François Olard1* — Hervé Di Benedetto* — Bernard Eckmann** — Jean-Claude Vaniscote*** * Département Génie Civil et Bâtiment, URA CNRS, ECOLE NATIONALE DES TPE Rue Maurice Audin, 69518 Vaulx-en-Velin Cedex, France 1since November 1, 2003 : APPIA, Direction Recherche & Développement, 8 rue du Dauphiné BP 374, 69960 Corbas Cedex, France ** EUROVIA, Direction des Techniques et de la Promotion Rueil-Malmaison, France *** APPIA, Direction Technique Issy-les-Moulineaux, France

ABSTRACT

A research including a large experimental campaign on the thermo-mechanical behavior of different bituminous materials in the large strain amplitude domain is proposed. The primary goal of this paper is to identify and determine the links between the failure properties of bituminous binders and those of mixes at low temperatures. The thermo-mechanical behavior of bituminous binders was evaluated with the tensile strength at a constant strain rate and constant temperatures. The thermo-mechanical behavior of bituminous mixes has been studied by performing measurements of the coefficient of thermal dilatation and contraction, tensile tests at constant temperatures and strain rates, and Thermal Stress Restrained Specimen Tests. Some pertinent links between fundamental properties of binders and mixes are established. Some characteristics which appear as pertinent and discriminating enough with regard to the low-temperature failure properties of bituminous mixes are presented.

Keywords : bitumens, bituminous mixes, rheological behavior, thermo-mechanical properties, failure properties, tensile strength, TSRST, low temperature, brittle, ductile, brittle/ductile transition temperature.


McCann - 1

Statistical Comparison Between SHRP Aggregate Physical and

Chemical Properties and an Asphalt Mixture’s Moisture Sensitivity

By:

Martin McCann, Ph.D., PE Western Research Institute

365 North 9th Street Laramie, WY 82072

Phone: 307-721-2254 Fax: 307-721-2300

E-mail: [email protected]

Richard Anderson-Sprecher, Ph.D. Department of Statistics University of Wyoming

Laramie, WY 82071-3332 Phone: 307-766-4289 Fax: 307-766-3927


Kenneth P. Thomas, Ph.D. Western Research Institute

365 North 9th Street Laramie, WY 82072

Phone: 307-721-2326 FAX: 307-721-2300


TRB 2004 Annual Meeting CD-ROM Original paper submittal – not revised by author.

McCann - 2

ABSTRACT The chemical and physical properties of aggregates used in hot mix asphalt play a significant role in establishing a mixture's moisture sensitivity. However, distinguishing the level of contribution of each property has been difficult due to the limitation on the number of variables that can be practically studied in an experimental plan. This paper compares multiple predictor variables associated with the chemical and physical properties of eleven SHRP aggregates. The aggregates were mixed with eight SHRP asphalts and the response variable was moisture sensitivity of a mix as determined by the freeze-thaw pedestal test.

An accelerated-failure-time, linear regression analysis was used to compare the predictor variables and rank the aggregate properties that contribute to the mixtures' moisture sensitivity. The most important predictor was acid insolubility with calcium oxide, silicon dioxide, loss on ignition, and the zeta potential all being highly correlated with acid insolubility. Porosity was the second most important predictor variable. In addition, iron oxide, aluminum oxide, surface area, and potassium oxide all were found to contribute to moisture sensitivity, but the variables were not mutually exclusive.


Andriescu, Hesp and Youtcheff 2

ON THE ESSENTIAL AND PLASTIC WORKS OF DUCTILE FRACTURE IN ASPHALT BINDERS Adrian Andriescu and Simon A.M. Hesp, Department of Chemistry, Queen’s University, Kingston, Ontario, K7L 3N6 Canada John S. Youtcheff, Turner-Fairbanks Highway Research Center, Federal Highway Administration, McLean, Virginia, 22101-2296 USA ABSTRACT At present there is no satisfactory asphalt binder test method that can relate properties measured in the laboratory to fatigue performance in service. The loss modulus of the binder, G*sinδ, as proposed by the Strategic Highway Research Program, is a rheological parameter that measures the energy dissipated within the homogeneous binder at low strains under dynamic conditions. It has been reported in a number of publications that this binder parameter provides little correlation with the susceptibility of the asphalt concrete to fracture at high strains in the non-linear regime under simulated in service conditions. This paper explores the essential work of fracture method, which is an energy-based testing approach used for the fracture characterization of ductile materials. Given the fact that at ambient temperatures asphalt is a ductile material, it is only reasonable to assume that the essential work of fracture method yields valuable information with likely use in fatigue performance ranking. The binders investigated for this study showed a wide range of essential and plastic works of fracture at ambient temperature and a single rate of loading. Although only six binders were evaluated their works of fracture are contrasted with other properties.


A Model for Predicting Damage Evolution in Heterogeneous Viscoelastic Asphaltic Mixtures

Submission date: 11/15/2003 Word count: 7,269

Flávio Vasconcelos de Souza Universidade Federal do Ceará Campus do Pici, s/n – Bloco 703 Zip code: 60.455-760 - Fortaleza, CE – Brazil (55)(85) 288.9572 – R 242 [email protected] Jorge Barbosa Soares Universidade Federal do Ceará Campus do Pici, s/n – Bloco 703 Zip code: 60.455-760 - Fortaleza, CE – Brazil (55)(85) 288.9572 – R 244 [email protected] David H. Allen University of Nebraska – Lincoln College of Engineering Zip code: 68588 - Lincoln, Nebraska (402) 472-3181 [email protected] Francisco Evangelista Jr. Universidade Federal do Ceará Campus do Pici, s/n – Bloco 703 Zip code: 60.455-760 - Fortaleza, CE – Brazil (55)(85) 288.9572 – R 242 [email protected] ABSTRACT Cracking in the asphaltic layer of pavements has been shown to be a major source of distress in roadways. Previous studies in asphaltic mixture cracking have typically not considered the material heterogeneity. This paper presents the sequel of a study in which the binder and the aggregates were treated as distinct materials. In this paper, besides the consideration of the viscoelastic behavior of the bulk asphalt binder, a micromechanical viscoelastic cohesive zone model that introduces ductility at the crack tip has also been considered. The simulations performed are verified and calibrated from simple and conventional laboratory tests. The study investigates crack evolution under monotonic loading, even though the method outlined can be further developed for the investigation of asphalt mixture fatigue. Key Words: Asphalt Mixture, Finite Elements, Viscoelasticity, Cohesive Zone, Damage


1

Duplication for publication or sale is strictly prohibited without prior written permission

of the Transportation Research Board.

Title: “Implications of Experimental Measurements and Analyses of the Internal Structure of HMA”

Authors:

Eyad Masad1 and Joe Button2 1 Assistant Professor,

E-mail: [email protected], Tel: 979-845-8308, Fax: 979-845-0278 3 Head of Pavement and Materials Division

E-mail: [email protected], Tel: 979-845-9847, Fax: 979-845-0278 Texas Transportation Institute Texas A&M University 3135 TAMU College Station, TX 77843-3135

Transportation Research Board 83rd Annual Meeting January 11-15, 2004 Washington, D.C.

Number of words=(4250 WORDS + 1 Table@250 + 12 Figures@250) = 7500


2

ABSTRACT This paper summarizes the experimental and analysis methods used in characterizing and quantifying the internal structure of hot mix asphalt (HMA) paving mixtures. The implications of the internal structure analysis on the design, compaction, and performance of HMA are also discussed. The presented methods can be divided into two main categories, namely “volumetric analysis methods”, and “imaging methods”. The volumetric analysis methods rely on bulk measurements of the percentage of air voids in certain aggregate sizes or in the whole mix as indicators of packing. These concepts are currently employed in the Superpave design system for dense-graded HMA, stone matrix asphalt (SMA) design, and the Bailey method for the selection of aggregate gradations in HMA. The imaging methods quantify the distribution of the aggregate skeleton, voids in the mineral aggregate (VMA), and air voids by analyzing images of the internal structure. These images can be two dimensional captured using a simple setup of a microscope connected to camera or three dimensional captured using an X-ray computed tomography system.


Collins et al 1

Modulated Differential Scanning Calorimetry of SBS and its Blends with Bitumen

Peter Collins, Gary Polomark and Jean-Francois. Masson*

Institute for Research in Construction, National Research Council of Canada

*To whom correspondence should be addressed. Phone: (613) 993-1244).

Fax: (613) 952-5102. E-mail: [email protected]

Abstract

Modulated differential scanning calorimetry (MDSC) was used to study phases in SBS,

bitumen, and their blends. MDSC allows for separating thermal transitions that arise from

amorphous and ordered phases by the acquisition of reversing and non-reversing heat

flow signals. The reversing heat flow curve for a linear SBS block copolymer showed a

glass transition temperature (Tg) for the polybutadiene (PB) block at –88°C and another

for the polystyrene (PS) block at 60°C, down from the Tg of neat PS at 105°C. The non-

reversing heat flow curve showed an order-disorder transition at 0 to 20°C that arose

from the PS/PB interface, in addition to stress relaxation during the glass transitions of

the PS and PB blocks. The reversing heat flow curve for bitumen showed four Tgs, one

from each of its fractions, whereas the non-reversing heat flow curve showed exothermic

cold-crystallization (CC) and endothermic steric hardening (SH). In blends of bitumen

with 3%, 6%, and 10% SBS changes or shifts in Tgs, CC and SH intensities were

measured by MDSC. It was found that bitumen blended with the PB block in SBS, but

not with the PS block. Upon blending, a mixed PB-maltenic phase was produced, in

which only about 30% of the maltenes participate. It was also found that SBS reduced

both CC and SH in bitumen, the reduction being disproportionately higher than expected

based on polymer concentration. MDSC was also used in an attempt to assess the hot-

storage stability of the blends.


Effect of the Newly Developed Cellulose Oil Palm Fiber in the Fatigue Cracking of Stone Mastic Asphalt Ratnasamy Muniandy1

1 Lecturer, Civil Engineering, Universiti Putra Malaysia, 43400 Serdang, Malaysia Email: [email protected] Email: [email protected] Tel : 603 8946 6373 (after August) Tel: 605 688 6015 (until August) Fax: 603 8656 7103 (after August) Fax : 605 688 5878 (until August) Ali A. Selim2

2 Professor of Civil & Environmental Engineering, South Dakota State University, Brookings SD 57007 Email : [email protected] Tel: 605 688 4138 Fax: 605 688 5878 Vernon R.Schaefer3

3 Professor of Civil Engineering, Iowa State University, Ames, IA 50011 Email: [email protected] Tel: 515-294-9540 Fax: 515-294-8216

Total Word Count = 6943


Ratna Muniandy, Ali A. Selim, Vernon R. Schaefer

2

Abstract: Stone Matrix Asphalt (SMA) mixes have performed very well in resisting rutting. Not enough research was performed on fatigue resistance of SMA. A was undertaken, to evaluate the effect of the newly developed cellulose oil palm fiber in the fatigue failure of SMA mixes. The use of cellulose fibers in asphalt mixes has generally been limited to gap graded mixtures such as Stone Matrix Asphalt (SMA) and Open Graded Friction Courses (CGFC) and then only to minimize the drain-down of asphalt. The results reported here in, looked into the use of cellulose oil palm fiber (COPF), a native product of Malaysia, in the enhancement of resistance to fatigue cracking. 150 mm by 50 mm thick cylindrical specimens were prepared and tested at 20°C with various proportions (0.0%, 0.2%, 0.4%, 0.6%, 0.8%, and1.0%) of cellulose oil palm fibers. The specimens were loaded at a constant deformation rate of 5 mm per minute of vertical ram movement until failure. The load, deformations, crack initiation and propagation were measured and analyzed. Two new terms are introduced in this paper. The first one is called Sustenance Ratio (SR) and it represents the ratio of the drop in stiffness between maximum load and first crack divided by time in seconds. The second term is Crack Meander (CM) whereby the more resistant mixes tend to have larger crack meander. The study showed remarkable enhancement in the fatigue resistance, for a fiber range of 0.6 percent by weight of total mix. Keywords: Cellulose Fiber; Stone Mastic Asphalt; Tensile Strength; Sustenance Ratio; Crack Meander


Initial Validation of a New Surface Performance-Graded (SPG) Binder Specification

Authors:

Lubinda F. Walubita1,Amy Epps Martin2,

Darren Hazlett3,and

Roberto Barcena 4

November 13, 2003

Submitted for presentation and publication at the 83rd Annual Meeting of the Transportation Research Board, Washington, D.C., January, 2004.

1 Research Assistant, Texas Transportation Institute, 501H CE/TTI Building, 3136 TAMU, College Station, TX 77843-3136, (979) 845-5982, Fax (979) 845-1701, Email: [email protected]

2 Assistant Professor, Texas A&M University, 503F CE/TTI Building, 3136 TAMU, College Station, TX 77843-3136, (979) 862-1750, Fax (979) 845-0278, Email: [email protected]

3 Chemical Engineering Branch Manager, CST-M&P, Texas Department of Transportation. 125 E. 11th St, Austin, TX 78701-2483, (512) 506-5816, FAX (512) 506-5825, Email: [email protected]

4 Staff Engineer, ERES Consultants, 9030 Red Branch Rd,Suite 210, Columbia, MD 21045, (410) 997-6181, FAX (410) 997-6413, Email: [email protected]


LF. Walubita, A. Epps Martin, D. Hazlett, and R. Barcena 2

Initial Validation of a New Surface Performance-Graded (SPG) Binder Specification

ABSTRACT

Presently, surface treatment design and material selection is based on traditional specifications and experience, which are not performance-based and sometimes result in inadequate performance of the surface treatment. In 2000 the first phase of a Texas Department of Transportation (TxDOT) research study developed a surface performance-graded (SPG) specification for the selection of surface treatment binders. The SPG specification is performance-based and utilizes binder properties directly related to surface treatment performance and associated distresses. The specification takes into account environmental conditions, aging effects of the binder, visco-elastic behavior, and reliability.

The objective of the second phase of the study discussed in this paper was to (1) investigate and establish the validity and applicability of the proposed SPG specification by comparing laboratory measured SPG binder grades to actual observed field performance and where necessary make modifications and (2) recommend the SPG specification for practical implementation. The research methodology involved highway section identification including project data collection, laboratory testing including binder SPG grading, field performance monitoring, and data analysis. Factors included in the experimental design were binder type and suppliers, environment, aggregates, and traffic. Analyses of the results showed that there was generally a good correlation between the proposed SPG specification and actual field performance. Overall the results indicate that the proposed SPG specification is functional; and if properly applied, it promises to be a relatively cost-effective method for selecting binders towards ensuring adequate surface treatment performance.

Keywords: Surface treatment, binder, asphalt cement, emulsion, specification, performance, aggregate loss, bleeding.


Comparison of Performance and Cost between Superpave and Conventional Hot-Mix Asphalt in Washington State

by

Kim A. Willoughby Washington State Department of Transportation P.O. Box 47365 Olympia, WA 98504-7365 Phone: (360) 709-5474 Fax: (360) 709-5588 [email protected]

Linda M. Pierce Washington State Department of Transportation P.O. Box 47365 Olympia, WA 98504-7365 Phone: (360) 709-5470 Fax: (360) 709-5588 [email protected]

Jim Weston Washington State Department of Transportation P.O. Box 47365 Olympia, WA 98504-7365 Phone: (360) 709-5496 Fax: (360) 709-5588 [email protected]

Joe P. Mahoney Civil and Environmental Engineering University of Washington Box 352700 Seattle, WA 98195-2700 Phone: (206) 685-1760 Fax: (206) 543-1543 [email protected]

For presentation at the 2004 TRB Annual Meeting

Prepared July 2003 Revised November 2003

Number of Words = 5,433 Tables and Figures = 2,250

Total Number of Words = 7,683


Willoughby, et al. 1

ABSTRACT WSDOT began placing Superpave in 1996 and has placed an increasing number of projects each year, totaling approximately 1.9 million tonnes (2.1 million tons) and covering 1,753 lane-kilometers (1,089 lane-miles). After being in place for a maximum of six years, an evaluation of the field performance, unit prices, and costs per lane-kilometer were compared to WSDOT’s conventional HMA. Although none of the Superpave projects have reached the end of their performance life, the purpose of this limited study is to answer the question whether Superpave is performing as well as conventional HMA in Washington State. The data presented shows that in most cases, Superpave is performing as well as, or better than, conventional HMA and the cost is approximately the same.


Kim, Little, and Lytton 1

PAPER NO. 04-2623 EFFECT OF MOISTURE DAMAGE ON MATERIAL PROPERTIES AND FATIGUE RESISTANCE OF ASPHALT MIXTURES YONG-RAK KIM Research Associate, Department of Civil Engineering, 146 Walter Scott Engineering Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0531 E-mail: [email protected] DALLAS N. LITTLE (Corresponding Author) Professor, Department of Civil Engineering, 601 CE/TTI Building, Texas A&M University, College Station, Texas 77843-3135 Phone: (979) 845-9963, Fax: (979) 845-0278, E-mail: [email protected] And ROBERT L. LYTTON Professor, Department of Civil Engineering, 508G CE/TTI Building, Texas A&M University, College Station, Texas 77843-3135 Phone: (979) 845-8211, Fax: (979) 845-0278, E-mail: [email protected]

Word Counts Abstract 190 Text without figures or tables 5144 Tables (2 @ 250 each) 500 Figures (6 @ 250 each) 1500 Total 7334

Paper Submitted to the Transportation Research Board for Presentation and Publication at the 2004 Annual Meeting in Washington, D.C.


Kim, Little, and Lytton 2

ABSTRACT Dynamic mechanical analysis (DMA) is used to successfully evaluate complex characteristics of fatigue damage and fracture of asphalt binders and mastics by measuring fundamental viscoelastic properties and damage characteristics. DMA is used to define the effect of moisture on fatigue damage in the asphalt mastic fraction. Dynamic frequency sweep and time sweep tests were performed on cylindrical sand asphalt samples in a dry state and after being subjected to moisture saturation. Test results clearly demonstrate that moisture reduces viscoelastic stiffness, fatigue resistance, and eventually fatigue life of sand asphalt. The mechanistic role of moisture in fatigue is analyzed and quantified using nonlinear viscoelastic theory based on pseudo variable concepts and a continuum damage fatigue model. The effect of material surface energies, which is strongly related to fracture and damage, is further discussed by employing DMA fatigue test results and varying surface energy characteristics of individual mixture constituents. The DMA experimental procedure and analysis is an efficient way to identify the influence of moisture on the mastic and to compare various mastics in terms of moisture susceptibility. Key Words: Asphalt, Fatigue, Moisture Damage, Viscoelasticity


MODELLING THE BEHAVIOUR OF AN IDEALISED ASPHALT MIXTURE USING THE DISTINCT ELEMENT METHOD

Andrew C. Collop+, Glenn R. McDowell* and York Lee+

+ Nottingham Centre for Pavement Engineering University of Nottingham, University Park

Nottingham NG7 2RD, UK Tel: +44 (0)115 951 3935 Fax: +44 (0)115 951 3898

Email: [email protected]

* Nottingham Centre for Geomechanics University of Nottingham, Nottingham

Paper submitted for the TRB 83nd Annual Meeting Washington DC, Jan 11-15th, 2004

(Section A2K05)

Total Number of Words: 6,249 Last Revised: 04/08/2003


Collop, McDowell & Lee 1

ABSTRACT This paper investigates the use of Distinct Element Modelling (DEM) to simulate the behaviour of a highly idealised bituminous mixture in a uniaxial compressive creep test. The idealised mixture comprises single-sized spherical (sand-sized) particles mixed with bitumen and was chosen so that the packing characteristics are known (dense random packing) and the behaviour of the mixture will be dominated by the bitumen and complex aggregate interlock effects will be minimised. In this type of approach the effect of the bitumen is represented as shear and normal contact stiffnesses. A numerical sample preparation procedure has been developed to ensure that the final specimen is isotropic and has the correct volumetrics. Elastic contact properties have been used to investigate the effect of sample size (number of particles) and the effect of the values of the shear and normal contact stiffnesses on bulk material properties (bulk modulus and Poisson’s ratio). It was found that a sample containing at least 4,500 particles is required for Young’s modulus and Poisson’s ratio to be within 2% of the values calculated using a much larger number of particles. The bulk modulus was found to be linearly dependent on the normal contact stiffness and independent of the shear contact stiffness. A mean field approach was used to develop a theoretical model that predicted this behaviour. Poisson’s ratio was found to be dependent on only the ratio of the shear contact stiffness to the normal contact stiffness. A simple visco-elasto-plastic Burger’s model was introduced to give a time dependent shear and normal contact stiffnesses. Simulation results showed that, using this model, it is possible to predict initial elastic, viscoelastic and viscoplastic behaviour.


THE EFFECT OF MATERIAL TRANSFER DEVICES ON FLEXIBLE PAVEMENT SMOOTHNESS

By Jennifer Kristy Harris

PDP Intern Federal Highway Administration 500 Eastern Boulevard, Suite 200

Montgomery, AL 36117 Phone: (334) 223-7390 Fax: (334) 223-7325

[email protected]

Frazier Parker Director, Highway Research Center

Auburn University Auburn, AL 36849

Phone: (334) 844-6284 Fax: (334) 844-6290

[email protected]

and

Mary Stroup-Gardiner Associate Professor

Civil Engineering Department Auburn University Auburn, AL 36849

Phone: (334) 844-6280 Fax: (334) 844-6290

[email protected]

Prepared for

83rd Transportation Research Board Annual Meeting Washington D.C.

January 2004

Abstract = 192 words Text = 2623 words

Tables = 5 x 250 = 1250 Figures = 6 x 250 = 1500

Total = 5565 words


Harris, Parker and Stroup-Gardiner

ABSTRACT The initial smoothness of a pavement is linked to both future pavement smoothness and

pavement life. Research was conducted to study the effects of adding a material transfer device to the paving train. The focus was to determine if the use of a material transfer device improves flexible pavement smoothness. An automated data collection van was used to collect pavement profile data and smoothness was quantified in terms of the International Roughness Index (IRI) in inches per mile. An infrared camera and rolling wheel were used to detect and locate portions of the mat with temperature differences of over 10EC (19E F).

It was found that a material transfer device significantly improves flexible pavement smoothness. Fewer areas with temperature differences over 10EC (19E F) were noted when a material transfer device was used, and areas with these temperature differences were found to be significantly rougher than locations that had more uniform temperatures. An additional finding, unrelated to the use of a material transfer device, was that the extension of the screed to one side of the paver causes a significant increase in roughness in the wheelpath on that side. Keywords: Flexible Pavement, Material Transfer Devices, Smoothness, IRI


EVALUATION OF THE DYNAMIC ANGLE VALIDATOR (DAV)

Howard L. Moseley 352.955.2919

[email protected]

Gale C. Page 352.955.2903

[email protected]

James A. Musselman 352.955.2905

[email protected]

Gregory A. Sholar 352.955.2920

[email protected]

Patrick B. Upshaw 352.955.2906

[email protected]

FLORIDA DEPARTMENT OF TRANSPORTATION 5007 NE 39th Avenue Gainesville, FL 32609

Fax: 352.955.6629

Submitted to the Transportation Research Board for 2004 Submitted: November 14, 2003

Word Count: Text: 3663 words Tables and Figures: 12 @ 250 words each = 3000 words Total: 6663 words


Moseley, Page, Musselman, Sholar, Upshaw

1

ABSTRACT Current test methods specify that the angle of gyration of a Superpave gyratory compactor (SGC) be measured externally or outside of the mold. The external angle of gyration may not accurately portray the actual angle inside the mold during compaction. Significant differences in compacted density have been seen in specimens compacted with different SGCs. Measuring the angle of gyration inside the mold would reveal the cause for varied levels of compaction in different SGCs. The dynamic angle validator (DAV) was developed to measure the internal angle of gyration. The Florida Department of Transportation (FDOT) evaluated the DAV with several mixtures and compactors. Mixture stiffness had an effect on the internal angle measurement in some SGCs. Measuring and setting SGC angles of gyration internally statewide should reduce the variability in compacted density between different SGCs. There are other factors not related to angle of gyration that can contribute to density variability. The compactor needs to be in good working order, clean, and the molds and plates need to be checked for wear. These factors should also be addressed on a statewide basis.


PERFORMANCE OF COLD IN PLACE RECYCLING IN NEVADA

Authors:

Peter E. Sebaaly1 Gabriel Bazi2 Edgard Hitti3 Dean Weitzel4

Sohila Bemanian5

A Paper Submitted for Publication Transportation Research Board

Annual Meeting January 11-15, 2004

Washington D.C.

1. Professor and Director, Pavements/Materials Program, Department of Civil Engineering, University of Nevada, Reno, NV 89557,775-784-6565, [email protected] 2. Graduate Research Assistant, Pavements/Materials Program, Department of Civil Engineering, University of Nevada, Reno, NV 89557,775-784-1172, [email protected] 3. Research Engineer, Pavements/Materials Program, Department of Civil Engineering, University of Nevada, Reno, NV 89557,775-784-1180, [email protected] 4. Chief Materials Engineer, Materials Division, Nevada Department of Transportation, 1263 S. Stewart St, Carson City, NV 89712, 775-888-7520, [email protected] 5. Assistant Materials Engineer, Materials Division, Nevada Department of Transportation, 1263 S. Stewart St, Carson City, NV 89712, 775-888-7520, [email protected]


Sebaaly, Bazi, Hitti, Weitzel, Bemanian

1

ABSTRACT

In light of the increasing cost of hot mixed asphalt (HMA) mixtures and the limited

availability of good materials, cold in place recycling (CIR) offers an attractive alternative for

rehabilitating asphalt pavements. Because of its limited performance history and the un-

availability of a standard mix design procedure, the use of CIR mixtures has been limited to low-

medium volume roads. For over a decade, many highway agencies have experimented with,

and/or used CIR mixtures and reported numerous successes.

The Nevada Department of Transportation is currently using CIR on low-medium

volume roads. The CIR layer is treated as a stabilized base course followed by a thin HMA

overlay. As part of this program, NDOT developed a mix design procedure based on the Hveem

mix design method to establish the optimum moisture and emulsion contents. The design

procedure evaluates the moisture sensitivity of the CIR mixture and determines the need for lime

treatment of the CIR mix. The basic concept of the mix design is to assess the ability of the CIR

process in providing a flexible and stable mix which can withstand the combined action of traffic

loads and environment. The designed CIR mixtures were implemented on three field projects

and showed excellent performance which led NDOT to construct additional CIR projects.

INTRODUCTION

When rehabilitating a flexible pavement, the engineer must deal with both budget

constraints and the availability of materials. Under these circumstances the recycling of the

existing pavement proves to offer an effective alternative which has the potential of reducing the

cost and waste generation of pavement rehabilitation. Recycling of the existing pavement offers

an attractive approach for effectively dealing with the distressed pavement surface. A severely

cracked pavement presents a challenge for the design engineer due to its potential of reflecting


Hassan Salem & Fouad Bayomy 1

Prediction of Seasonal Variation of the Asphalt Concrete Modulus Using LTPP Data

By Hassan M. Salem (Corresponding Author) PhD Candidate Department of Civil Engineering University of Idaho Moscow, ID 83844-1022 Ph. 208-885-6818, Fax. 208-885-6608 E-mail: [email protected] & Fouad M. Bayomy Professor Department of Civil Engineering University of Idaho Moscow, ID 83844-1022 Ph. 208-885-6784, Fax. 208-885-6608 E-mail: [email protected]

Word Count: Abstract 197 Text 4883 No of Figures is 6 1500 No of Tables is 2 500 Total 7080


Hassan Salem & Fouad Bayomy 2

Prediction of Seasonal Variation of the Asphalt Concrete Modulus Using LTPP Data

By

Hassan M. Salem and Fouad M. Bayomy

ABSTRACT

This paper addresses the seasonal variation of the asphalt concrete (AC) modulus with the change in pavement temperature at various seasons. The main goal of the research was to develop regression models that can enable design engineers to assess the seasonal changes in AC modulus, and to develop an algorithm for calculating a seasonal adjustment factor (SAF) that allows estimating AC modulus at any season from a known reference value. The study is based on analyzing data collected at LTPP sites in both freezing and nonfreezing zones. The data was obtained from the LTPP database in the DataPave 3.0 software.

The approach adopted in this study was to select LTPP-SMP sites that represent various climatic regions and use the backcalculated modulus and pavement temperature data to develop regression models for the modulus-temperature relationships for various sites in both freezing and nonfreezing zones.

Two regression models were developed to relate the variation in modulus with the variation in pavement temperatures at various seasons for both freezing and nonfreezing zones. These models incorporate AC layer properties such as AC layer thickness, maximum mix specific gravity, asphalt binder percentage and viscosity. A model for determining the SAF was also developed.


EVALUATION OF USE OF SYNTHETIC LIGHTWEIGHT AGGREGATE (SLA) IN HOT MIX ASPHALT

Frederick P. Hooper GeoTesting Express, Inc.

Materials Technology Center 1145 Massachusetts Avenue

Boxborough, MA 01719 Phone: (978) 635-0424 Fax: (978) 635-0266

email: [email protected]

Rajib B. Mallick (Corresponding author)

Civil and Environmental Engineering Department Worcester Polytechnic Institute

Worcester, MA 01609 Phone: 508 831 5289

Fax: 508 831 5808 e-mail: [email protected]

Sean O’Brien

Graduate Student Civil and Environmental Engineering Department

Worcester Polytechnic Institute Worcester, MA 01609 Phone: 508 831 6034

Fax: 508 831 5808 e-mail: [email protected]

Mohsen Kashi DMJM Harris

66 Long Wharf 2nd Floor

Boston MA 02110 Phone: 617-994-6211 Fax: 617-723-6856


Paper prepared for presentation and publication at the 83rd Transportation Research

Board Annual Meeting, Washington, DC, January 11-15, 2004


EVALUATION OF USE OF SYNTHETIC LIGHTWEIGHT AGGREGATE (SLA) IN HOT MIX ASPHALT

Frederick P. Hooper

Rajib B. Mallick Sean O’Brien Mohsen Kashi

ABSTRACT

Successful use of Synthetic Lightweight Aggregates made from waste flyash and plastics can help in conserving mineral aggregates and reusing waste materials. The objective of this study was to evaluate the use of Synthetic Lightweight Aggregate made from waste fly ash and plastics in Hot Mix Asphalt. The scope of this laboratory study included preparation of aggregate blends and mixes with different percentages of Synthetic Lightweight Aggregates, compaction of samples, testing of samples and analysis of results. Mixes were made with 0, 5, 10, 15 and 20 percent Synthetic Lightweight Aggregates by weight of aggregates. Tests included bulk specific gravity, theoretical maximum density, resilient modulus and indirect tensile strength at 25oC on unconditioned and conditioned samples, and rut testing with a wheel tracking equipment at 60oC. Test results were analyzed statistically to determine the effect of Synthetic Lightweight Aggregates on Hot Mix Asphalt properties. The results indicate that the inclusion of Synthetic Lightweight Aggregates enhances stiffness, and resistance against rutting and moisture induced damage of Hot Mix Asphalt. A relatively high absorption was noted for mixes containing 20 percent Synthetic Lightweight Aggregates. The main conclusions are that Synthetic Lightweight Aggregate has excellent potential of being used as part of Hot Mix Asphalt, and that 15 percent by weight of aggregate seems to be an optimum amount for use. Further work should be carried on to determine the effect of Synthetic Lightweight Aggregate on low temperature properties of Hot Mix Asphalt.


WORKABILITY OF HOT MIX ASPHALT

By

Jagan M. Gudimettla Graduate Research Assistant

National Center for Asphalt Technology Auburn University

L. Allen Cooley, Jr. Senior Geotechnical/Pavement Engineer

Burns Cooley Dennis, Inc. Jackson, Mississippi

(Formerly National Center for Asphalt Technology) (Corresponding Author)

E. Ray Brown Director

National Center for Asphalt Technology Auburn University

“Prepared for presentation and publication at the 2004 Annual Meeting of the Transportation Research Board.”


2

WORKABILITY OF HOT MIX ASPHALT

Jagan M. Gudimettla, L. Allen Cooley, Jr., and E. Ray Brown

ABSTRACT

The term workability has been used to describe several properties related to the construction of hot mix asphalt (HMA). For this study, workability was defined as a property describing the ease with which a HMA can be placed, worked by hand, and compacted. This definition provides a term that is applicable to movement of HMA through equipment to the roadway, handwork of HMA, and compactibility on the roadway. The primary objective of this study was to evaluate a prototype device to measure the workability of HMA mixes that could identify the change in workability due to changes in mix characteristics. Based on the findings of this study a device was successfully designed to measure the workability of HMA mixes. The workability of HMA was affected by aggregate type, nominal maximum aggregate size (NMAS), binder type, and temperature. Gradation shape did not have a significant effect on workability. However, there were numerous two- and three-way interactions that were significant that included gradation shape. Mixes modified to meet a PG 76-22 were significantly less workable than mixes containing an unmodified PG 64-22. There was a relationship between workability and temperature that showed increased workability at higher temperatures.


Sebaaly, P.E., A.J.T. Hand, W.M. McNamara, D. Weitzel, J.A. Epps

1

FIELD AND LABORATORY PERFORMANCE OF SUPERPAVE MIXTURES IN NEVADA

Authors:

Peter E. Sebaaly1 Adam J.T. Hand (corresponding author) 2

W. Marty McNamara3

Dean Weitzel4 Jon A. Epps5

November 7, 2003

Submitted for consideration for publication and presentation to: Transportation Research Board

Word Count 4845 Tables (9x250)= 2250 Figures (1x250) = 250 Total = 7345 1 Professor, Department of Civil Engineering, University of Nevada, Reno, Nevada 89557, Phone: 775-784-6565, Fax: 775-784-1429, [email protected] 2 Quality Systems Engineer, Granite Construction Inc., 1900 Glendale Avenue, Sparks, NV 89431, Phone: 775-352-1953, Fax: 775-355-3431, [email protected] 3 Staff Engineer, Granite Construction Inc., 1900 Glendale Avenue, Sparks, NV 89431, Phone: 775-352-1973, Fax: 775-355-3431, [email protected] 4 Chief Materials Engineer, Materials Division, Nevada DOT, 1263 S. Stewart Street, Carson City, NV 89712, Phone: 775-888-7520, Fax: 775-888-7115, [email protected] 5 Engineering Services Manager, Granite Construction Inc., 1900 Glendale Avenue, Sparks, NV 89431, Phone: 775-352-1954, Fax: 775-355-3431, [email protected]


Using a Single Test to Determine Specific Gravity and Absorption of Aggregate Blends

(Word Count: 246 – Abstract; 3255 – Text; 3000 – Figures & Tables)

By

Kevin D. Hall Professor

University of Arkansas Department of Civil Engineering

4190 Bell Engineering Center [email protected]

(501) 575-8695 (501) 575-7168 Fax

Paper prepared for Publication and Presentation at the 2004 Annual Meeting of the Transportation Research Board

November 2003


Using a Single Test to Determine Specific Gravity and Absorption of Aggregate Blends

Kevin D. Hall

ABSTRACT

The ability to accurately and consistently measure the specific gravity of an aggregate is

paramount to transportation materials engineers. Current standard test methods (AASHTO T-84

and T-85) are not typically used for routine quality control purposes due to long testing times and

questions concerning variability. Among new techniques developed for measuring specific

gravity and absorption is a vacuum sealing method, which eliminates the need for long soaking

periods and the need to determine aggregate mass in a saturated-surface-dry moisture state. The

vacuum sealing method also has the potential for measuring the specific gravity of a blend of

aggregates in a single test. Specific gravity and absorption were measured on six coarse and four

fine aggregates comprised of a variety of mineralogy types, using both traditional and vacuum

seal methods. Ten blends, whose gradations generally met Superpave hot-mix asphalt

specifications, were created using various combinations of aggregates and tested in a single

vacuum seal test. Five replicate tests were performed on all individual aggregates and blends.

Aggregate blend single test results (specific gravity and absorption) were compared to values

obtained using traditional individual test results and mathematical combination. The

comparisons yielded generally strong correlations between methods, indicating the vacuum seal

procedure to have promise as a relatively rapid method for determining specific gravity and

absorption in a single test of an aggregate blend. However, some real differences in test values

suggest that the vacuum seal method needs refinement before it could be seamlessly substituted

for traditional methods.


Oxidation and Hardening Kinetics of the Rheological Function G'/(η'/G') in Asphalts

By

Pramitha Juristyarini, Richard R. Davison, Charles J. Glover*

A paper prepared for presentation and Publication at the 83rd Annual Meeting of theTransportation Research Board Washington D.C., January 2004

November 15, 2003

DEPARTMENT OF CHEMICAL ENGINEERING andTHE TEXAS TRANSPORTATION INSTITUTETEXAS A&M UNIVERSITYCOLLEGE STATION, TEXAS 77843-3122

(979) 845-3361FAX (979) 845-6446

*Corresponding author7239 words including tables and figures


Juristyarini, et al. 1

ABSTRACTOxidative hardening is a key asphalt property leading eventually to roadway failure.

However, incorporating it into specifications is complicated by the complexity of oxidationkinetics and the choice of physical property that best correlates with old roadway conditions andis readily measured. Literature studies report that ductility near 15 °C, 1 cm/min relates quitewell to age-related binder cracking failure, but this property is cumbersome to measure. A DSRfunction G'/( η'/ G') has been reported in the literature as an easily-measured and meaningfulsurrogate for 15 °C ductility. However, accelerated aging-rate data for this function arenecessary in order for it to be used in an aging criterion or specification.

In an attempt to find accelerated aging conditions that match roadway hardening withrespect to this function, nine asphalts were oxidized at various temperatures and pressures andcompared to hardening in a 60 °C room. The hardening kinetics for the DSR function are quitesimilar to earlier results obtained for log viscosity. For each, there is a rapid initial periodslowing to a constant rate period. This constant rate period for each hardening property wasrepresented by carbonyl formation rate times a carbonyl-sensitive constant or hardeningsusceptibility (HS). For both the DSR function and viscosity, both the HS and initial jump arepressure but not temperature dependent. A significant finding for pavement performance wasthat the DSR function initial jump was relatively higher than the viscosity initial jump. Asphaltswith the highest initial jump tended to have slower subsequent hardening but often not enoughslower to compensate for the initial jump.


EFFECT OF SUPERPAVE DEFINED RESTRICTED ZONE ON HOT MIX ASPHALT PERFORMANCE

by

Jingna Zhang (Corresponding Author)

Research Engineer National Center for Asphalt Technology

Auburn University, Alabama E-Mail: [email protected]

L. Allen Cooley, Jr.

Burns Cooley Dennis, Inc. Formerly, National Center for Asphalt Technology


Graham Hurley



Frazier Parker

Director Highway Research Center


Paper submitted for presentation and publication at the 83rd Annual Meeting of Transportation Research Board

Words = 3534 Tables/Figures (13×250) = 3250

Total Words = 6784


Zhang, Cooley, Hurley, and Parker

1

Effect of Superpave Defined Restricted Zone on Hot Mix Asphalt Performance

Jingna Zhang, L. Allen Cooley, Jr., Graham Hurley, and Frazier Parker

ABSTRACT The effect of the Superpave defined restricted zone on HMA rutting performance was evaluated. One gradation that violated the restricted zone (TRZ) and two gradations that did not violate the restricted zone (BRZ and ARZ) were evaluated. Mixes evaluated represented a range of maximum aggregate sizes (MAS), design traffic levels, and aggregate types. Three laboratory tests, Asphalt Pavement Analyzer, Rotary Loaded Wheel Tester, and Marshall test, were used to evaluate the rutting performance.

From the analysis, it was found that mixes having gradations violating the restricted zone performed similarly to or better than the mixes with gradations passing outside the restricted zone with respect to laboratory rutting tests. This conclusion was drawn from the results of experiments with 12.5 mm, 19.0 mm and 25.0 mm MAS gradations at Ndesign values of 100, 75, and 50 gyrations. This conclusion is confirmed and supported by a recently completed National Cooperative Highway Research Program project - NCHRP 9-14: “The Restricted Zone in the Superpave Aggregate Gradation Specification.” The results also showed that rutting performance of mixes having gradations below the restricted zone, which was commonly recognized to be rut-resistant, appears more sensitive to aggregate properties than do mixes having gradations above or through the restricted zone. KEY WORDS: Restricted Zone, Rutting Performance, Mix, Gradation


A Comparison of Falling-Head and Constant-Head Techniques For Estimating Field Permeability of HMA Pavements

(Word Count: 246 Abstract; 3730 Text; 3250 Tables & Figures)

By


Department of Civil Engineering University of Arkansas

4190 Bell Engineering Center Fayetteville, AR 72701

(501) 575-8695 (501) 575-7168 Fax [email protected]

Paper Prepared for Publication and Presentation at the 2004 Annual Meeting of the Transportation Research Board

November 2003


A Comparison of Falling-Head and Constant-Head Techniques For Estimating Field Permeability of HMA Pavements

Kevin D. Hall

ABSTRACT

Permeability of hot-mix asphalt continues to generate considerable interest in the asphalt

materials, design, and construction community. Ongoing studies of permeability report advances

in permeability testing techniques for both laboratory-based and field-based testing methods.

The University of Arkansas (UAF) has developed a constant-head field permeability test device

for use on in-place asphalt pavements. One constructed test section and sixteen in-service

pavements, including both new construction and overlays of existing pavements, were tested

using the UAF device and a falling-head field permeameter originally developed by the National

Center for Asphalt Technology (NCAT). At each of the field test sites, cores were taken from

the pavement and tested in the laboratory using the falling-head, constant-tail method described

in ASTM PS-129. A minimum of two field permeability measurements were taken at each site

using each permeability device; a minimum of three cores were taken from each test site for

testing in the laboratory. The total data set for this study includes over forty direct comparisons

of each field method and the laboratory results. The data indicate that the falling-head and

constant-head field methods yield significantly different permeability results, but display similar

test variability (based on replicate tests). Further, field permeability measured by the falling-

head method was significantly different from corresponding laboratory results, while constant-

head field results were not significantly different from laboratory results. It is suggested that

relative differences between field devices in initial applied hydraulic head and the test area

footprint are likely contributing factors to observed differences.


STUDY OF FATIGUE CRACKING MECHANISMS IN ASPHALT PAVEMENTS

USING THE VISCOELASTIC CONTINUUM DAMAGE FINITE ELEMENT PROGRAM

Sungho Mun, Ph.D. Postdoctoral Research Associate

Dept. of Civil Engineering, Box 7908 North Carolina State University

Raleigh, NC 27695-7908 Ph: (919) 515-4233 Fax: (919) 515-7908


Murthy N. Guddati, Ph.D.

Assistant Professor Dept. of Civil Engineering, Box 7908

North Carolina State University Raleigh, North Carolina 27695-7908

Ph: (919) 515-7699 Fax: (919) 515-7908


Y. Richard Kim, Ph.D., P.E.

(Corresponding Author) Professor


Raleigh, North Carolina 27695-7908 Ph: (919) 515-7758 Fax: (919) 515-7908


Submitted for Presentation at the 2004 TRB Annual Meeting and Publication in the Transportation Research Record: Journal of the Transportation Research Board.

Word Count: 7,500

November 2003


Mun et al.

1

ABSTRACT

This paper documents the findings from the study of fatigue cracking mechanisms in asphalt pavements using the finite element program (VECD-FEP++) that employs the viscoelastic continuum damage model for the asphalt layer and a nonlinear elastic model for unbound layers. Both bottom-up and top-down cracks are investigated by taking several important variables into account, such as asphalt layer thickness, layer stiffness, pressure distribution under loading, and load level applied on the pavement surface. The cracking mechanisms in various pavement structures under different loading conditions are studied by monitoring a damage contour. Preferred conditions for top-down cracking were identified using the results from this parametric study. The conjoined damage contours in thicker pavements suggest that the through-the-thickness crack may develop as the bottom-up and top-down cracks propagate simultaneously and coalesce together, supporting observations from field cores and raising the question of the validity of traditional fatigue performance models that account for the growth of the bottom-up cracking only. Keywords: fatigue cracking, top-down cracking, viscoelastic continuum damage, universal model, finite element, damage contour


Morian, Oswalt, Deodhar 1

Twenty Years Later – Experience with Cold In-Place Recycling as a Reflective Crack Control Technique Dennis A. Morian Quality Engineering Solutions, Inc. 405 Water St. P.O. Box 3004 Conneaut Lake, PA 16316 Phone (814) 382-0373 Fax (814) 382-0375 [email protected] Jeffrey Oswalt Pennsylvania DOT District 1-0 255 Elm St. Oil City, PA 16301 Phone (814)678-7109 Fax (814) 678-7032 [email protected] Akshay Deodhar Quality Engineering Solutions, Inc. 405 Water St. P.O. Box 3004 Conneaut Lake, PA 16316 Phone (814) 382-0373 Fax (814) 382-0375 [email protected] Submitted July 31, 2003 in response to Call for Papers for A2B04, Reflection Cracking, Causes, Mechanisms, and Rehabilitation Methods Word Count: 7388


Morian, Oswalt, Deodhar 2

Twenty Years Later – Experience with Cold In-Place Recycling as a Reflective Crack Control Technique ABSTRACT Cold in-place recycling (CIR) of existing hot mix asphalt materials has been an available treatment for over twenty years. This paper evaluates the performance of CIR projects and materials over that period. A total of forty-four pavement sections have been constructed by contractors in Northwestern Pennsylvania. Ninety additional sections have been recycled as a part of maintenance activities. (These latter are not included among the study sections). A subset of these projects has been evaluated to determine performance characteristics and cost effectiveness of the treatment and the material. The treatment is used typically on rehabilitation projects of roadways with 8,000 Average Daily Traffic (ADT) or less, but has been used on projects with up to 13,000 ADT. The performance of CIR in resisting reflective cracking from underlying concrete pavements, and material properties over time is discussed. Material layer stiffness was evaluated using backcalculation of deflection measurement methods. Additionally, the cost of constructing projects, and average cost effectiveness of these rehabilitation projects are discussed.


Analysis of Temperature Data for the NCAT Test Track

by

Donald E. Watson (Corresponding Author) Research Engineer E-Mail: [email protected] Jingna Zhang Research Engineer E-Mail: [email protected] R. Buzz Powell Manager, NCAT Test Track E-Mail: [email protected]

National Center for Asphalt Technology 277 Technology Parkway Auburn, AL 36830 Phone: (334) 844-6857 Fax: (334) 844-6853 Submitted July 28, 2003

Paper submitted for presentation and publication

at the 2004 Annual Meeting of the Transportation Research Board

Abstract = 209 Tables/Figures (9 x 250) = 2250

Text = 4949 Total Words = 7408


Watson, Zhang, and Powell 1

Analysis of Temperature Data for the NCAT Test Track

Donald E. Watson, Jingna Zhang, and R. Buzz Powell

ABSTRACT Several combinations of mix type, aggregate type, asphalt binder type and layer thickness are in place at the National Center for Asphalt Technology (NCAT) Test Track. It was desirable to examine the effects these various combinations may have on temperatures within the pavement. The purpose of this paper was to evaluate measured versus predicted temperatures, evaluate the effect of mix type on pavement temperature, and compare the effect of surface layer thickness on pavement temperatures. Based on temperature data from the NCAT Test Track, some of the general conclusions made are that (1) both the Strategic Highway Research Program (SHRP) and Long Term Pavement Performance (LTPP) temperature models slightly under-predict high pavement temperatures at 50 percent reliability and slightly over-predict temperatures at 98 percent reliability. (2) The low temperature models for SHRP over-predicted low pavement temperatures for both 50 and 98 percent reliability. The LTPP models were also overly conservative at 98 percent reliability. These results indicate that asphalt binders may not need to be as soft as specified in the Superpave performance grading system for low temperature performance. Keywords: Temperature, SHRP models, LTPP models, rutting, high 7-day temperature, low temperature.


TRB 04-3250

PRACTICAL USE OF EMPERICAL AND FUNDAMENTAL RHEOLOGICAL RELATIONSHIPS FOR THE PURPOSE OF SPECIFICATION OF POLYMER

MODIFIED BITUMEN

1. E. T. Hagos, MSc PhD student, Delft University of Technology (TU Delft)

Stevinweg 1 Post Box 5048

2600 GA, Delft, The Netherlands Phone: +31 (0)15 278 5066

Fax: +31 (0)15 278 3443 E-mail: [email protected]

2. J. M. M. Molenaar, MSc

Van der Burghweg 1 Post Box 5044



3. M. van de Ven, Associate Professor

Delft University of technology (TU Delft) Stevinweg 1

Post Box 5048 2600 GA, Delft, The Netherlands

Phone: +31 (0)15 278 2298 Fax: +31 (0)15 278 3443

E-mail: [email protected] Word count: 5244 + 2 tables + 7 figures = 7494


E.T. Hagos, J.M.M. Molenaar and M. van de Ven

2

ABSTRACT Empirical and fundamental rheological properties are related to develop technical specifications for polymer modified binder (PMB). The complex shear modulus and the zero shear viscosity are investigated for the binder’s contribution to the asphalt mixture’s resistance to permanent deformation (rutting in the pavement).

The rheological properties of PMB were determined as a function of the polymer content. EVA- and SBS-modified binders were prepared in the laboratory. The complex shear modulus, the dynamic viscosity, the complex viscosity, the penetration, and the Ring and Ball temperature were determined. It was found that each binder has a specific linear logarithmic G*-pen-relationship. Based on this, it can be shown that the Ring and Ball temperature is not suitable for the specification of the softening point of PMB. An alternative definition of the softening point of PMB is proposed. However, the penetration and the Ring and Ball temperature also remain useful for use with PMB for simple practical purposes, e.g. entry check. The zero-shear viscosity was investigated in relation to the delayed elasticity. It was found that theG*can be expected to predict satisfactorily the binder’s contribution to the asphalt concrete mixture’s resistance to permanent deformation at pavement temperatures above 40oC for the binders investigated. KKeeyywwoorrddss Complex modulus (G*), phase angle (δ), penetration (pen), softening point (Ring and Ball temperature), complex viscosity (η*), steady-state viscosity (η), Burgers model, Huet-Sayegh model


TRB 03-July

OPEN SYNTHETIC WEARING COURSE

1. M.F.C. van de Ven, Associate Professor Delft University of Technology (TU Delft)

Stevinweg 1 Post Box 5048



2. T.O. Medani, MTech, MSc.

PhD student, Delft University of Technology (TU Delft) Post Box 5048

2600 GA, Delft, The Netherlands Phone: +31 (0)15 278

Fax: +31 (0)15 2783443 E-mail: [email protected]

3. A.A.A. Molenaar, Professor

Delft University of technology (TU Delft) Stevinweg 1

Post Box 5048 2600 GA, Delft, The Netherlands

Phone: +31 (0)15 278 2298 Fax: +31 (0)15 278 3443

E-mail: [email protected] Word count: 5094 + 5 tables + 5 figures = 7594


M.F.C. van de Ven, T.O. Medani, A.A.A. Molenaar

2

ABSTRACT Increasing traffic loading and tyre pressures, environmental requirements like noise reduction and special solutions including unconfined loading situations put increasing demands on the materials used in pavement structures with special focus on the upper layers.

For flexible pavements it is necessary to search in certain applications for modified materials because of failing performance of asphalt concrete mixtures. Temperature susceptibility and in the case of porous asphalt mixtures low durability due to ravelling problems are examples of this. In a number of cases cement concrete is then used instead of even modified asphalt concrete mixture. To keep the advantages of flexible structures, it is necessary to develop new materials for the upper part of the pavement structure. In this paper such a material has been tested. The material concept is similar to a porous asphalt concrete, with as major difference the replacement of the bitumen with a very flexible polyurethane. Just like with porous asphalt concrete the voids can be filled with a cement mortar.

In this paper the mechanical properties of open synthetic wearing courses are discussed and compared with asphalt concrete and cement concrete. Important conclusion is that the strength properties, even at high temperatures, are at such a level that even unconfined loading situations are possible. KKeeyywwoorrddss Synthetic, OSWC, uni-axial tensile strength, master curves, maximum grain size


Brandon, Jared, Wu, and Geary 1

7418 words

Field and Laboratory Investigation of Permeable Asphalt Mixes on Georgia Highways

by

James M. Brandon, E.I.T. Special Projects Engineer, Bituminous Construction

[email protected]

David M. Jared, P.E. Special Research Engineer

[email protected]

Peter Y. Wu, Ph.D., P.E. Assistant State Materials & Research Engineer

[email protected]

Georgene M. Geary, P.E. State Materials & Research Engineer

[email protected]

Georgia Department of Transportation 15 Kennedy Drive

Forest Park, GA 30297-2599 Phone: (404) 363-7500 Fax: (404) 363-7684


Brandon, Jared, Wu, and Geary 2

ABSTRACT Georgia DOT (GDOT) investigated possible high permeability in asphalt mixes statewide, in response to reports of prolonged wetness on pavements around the state following rainfall. In these locations, high permeability manifested itself as wet areas on pavement surfaces where wetness remained after natural conditions should have removed all moisture from the surfaces. Sixteen project sites were inspected for problem areas statewide, and core specimens were taken from six of the sites. Specimens were taken from areas considered representative of the problem areas in each project. The specimens were tested to determine the permeability, bulk specific gravity, maximum theoretical specific gravity, percent air voids, percent asphalt cement, and gradation of the mix. Per the findings of this investigation, some Superpave mixes that were designed in accordance with GDOT specifications exhibited undesirable permeability. The investigation determined that both mix design and construction are contributory to permeable mixes; hence, permeability problems are to be corrected by a balanced adjustment to these processes, per the following recommendations: (1) for each Superpave mix type used in Georgia, develop mix-specific acceptance criteria for maximum in-place air voids; (2) include evaluation of mix permeability in mix design; and (3) provide continued quality control during construction operations to ensure the success of the mix-specific acceptance criteria.


A. E. Hunter, G. D. Airey & A. C. Collop 1

Aggregate Orientation and Segregation in Laboratory Compacted Asphalt Samples

Alistair E. Hunter (Corresponding Author) Nottingham Centre for Pavement Engineering, University of Nottingham, Nottingham, NG7 2RD Telephone: 0044 115 8466077 E-mail: [email protected]: 0044 115 9513909

Gordon D. Airey Nottingham Centre for Pavement Engineering, University of Nottingham, Nottingham, NG7 2RD Telephone: 0044 115 13913 E-mail: [email protected]: 0044 115 9513909

Andrew C. Collop Nottingham Centre for Pavement Engineering, University of Nottingham, Nottingham, NG7 2RD Telephone: 0044 115 13935 E-mail: [email protected]: 0044 115 9513909

Total Number of Words: 4937 words, 6 tables, 6 figures


A. E. Hunter, G. D. Airey & A. C. Collop 2

ABSTRACT

Differing laboratory compaction methods can produce volumetrically identical asphalt mixture specimens but with widely varying mechanical properties. Provided that the mixture design is constant, variations in the mechanical properties are probably due to differences in the structure of the aggregate-bitumen matrix. The objective of this paper is investigate the structure of the internal aggregate-bitumen matrix created by different laboratory compaction methods and compare this to the mechanical performance. This paper considers three types of laboratory compaction: Gyratory, Vibratory and Slab. Image Analysis (IA) techniques have been used to provide quantitative information on the orientation and distribution of aggregates on horizontal planes within asphalt mixture specimens. The IA results indicate that circumferential alignment of aggregate particles occurs in gyratory and vibratory compacted specimens. This behavior is more pronounced for larger aggregate particles and in those with an aspect ratio (maximum length / maximum width) greater than two. Slab compacted specimens display a more random particle orientation. The distribution and segregation of aggregates has been considered relative to the center of each horizontal asphalt specimen cross section. Whilst overall levels of aggregate particle density are similar across all the compaction methods considered, greater segregation occurs in Vibratory and Gyratory compacted specimens. Repeated Load Axial Testing (RLAT) has been undertaken on specimens compacted using each method. The results indicate a higher resistance to deformation in the Vibratory and Gyratory compacted samples compared to volumetrically identical Slab compacted samples.


LAB STUDY ON DEGRADATION OF STONE MATRIX

ASPHALT (SMA) MIXTURES

Hongbin Xie (Corresponding Author)

Graduate Research Assistant National Center for Asphalt Technology

277 Technology Parkway Auburn, AL 36830

Phone: (334) 844-6228 Fax: (334) 844-6248


Donald E. Watson Research Engineer

National Center for Asphalt Technology 277 Technology Parkway

Auburn, AL 36830 Phone: (334) 844-6228 Fax: (334) 844-6248


Submitted for presentation and publication at the 83rd Annual Meeting of the Transportation Research Board, Washington, D.C., January 2004

(2803 words + 7 Tables + 7 Figures = 6303 words)


Xie and Watson 1

ABSTRACT

Stone Matrix Asphalt (SMA) mixtures are designed to have a high coarse aggregate content and stone on stone contact which results in more stress on the coarse aggregate particles during compaction and traffic loads. Therefore, aggregates are more likely to break down in SMA mixtures than in conventional dense graded mixtures. Aggregate degradation during compaction and traffic loading may cause changes in the original gradation, and therefore may also affect the volumetric parameters for SMA mixtures.

In this study, five aggregates in three Nominal Maximum Aggregate Sizes (NMAS) were compacted by the Marshall hammer and Superpave Gyratory Compactor (SGC), which resulted in a total of thirty mix designs. The samples were prepared near optimum asphalt content and were extracted by the NCAT ignition oven, and the breakdown of aggregates was obtained by calculating the difference of compacted SMA mixtures and loose mixtures. The relationships between aggregate breakdown and influencing factors such as compaction effort, L.A abrasion, and Flat and Elongated (F&E) content were investigated. The influence of aggregate breakdown on volumetric properties was also investigated.

Aggregate breakdown by the Marshall hammer was found to be significantly higher than breakdown by the SGC. LA abrasion was found to have a strong relationship with aggregate breakdown, and was also directly related to the Voids in Mineral Aggregate (VMA) of SMA mixtures. F&E content had a moderate relationship with aggregate breakdown, but had relatively little effect on VMA. KEY WORDS: Stone Matrix Asphalt (SMA), Breakdown, L.A. Abrasion, Flat and Elongated Content, Void in mineral aggregate (VMA).


PREDICTION OF THERMAL CRACKING BEHAVIOR OF ASPHALT CONCRETE USING THE VISCOELASTOPLASTIC CONTINUUM DAMAGE MODEL

Ghassan R. Chehab, Ph.D. Postdoctoral Research Associate

Campus Box 7908 Dept. of Civil, Construction, & Env. Engineering

North Carolina State University Raleigh, NC 27695-7908

Phone: 919-515-7735 E-mail: [email protected]

Y. Richard Kim, Ph.D., P.E.

(Corresponding Author) Professor

Campus Box 7908 Dept. of Civil, Construction, & Env. Engineering

North Carolina State University Raleigh, NC 27695-7908

Phone: 919-515-7758 E-mail: [email protected]

Matthew W. Witczak, Ph.D.

Professor Dept. of Civil and Env. Engineering

Arizona State University Tempe, AZ 85287-5306 Phone: (480) 965-3589


Ramon Bonaquist, Ph.D. Advanced Asphalt Technologies

108 Powers Ct., Suite 100 Sterling, VA 20166

Phone: (703) 444-4200 Email: [email protected]

Paper Submitted for Presentation and Inclusion in the TRB 83rd Annual Meeting Proceedings Word Count: (5247 Text + (1 Table and 8 Figures) x 250 = 7497 words)

November 14, 2003


Chehab et al.

2

ABSTRACT

In this paper, the viscoelastoplastic continuum damage model, recently developed under the auspices of the NCHRP 9-19 project entitled “Advanced Mixture Characterization for the Superpave Support and Performance Models Management”, is applied to the prediction of the thermal cracking behavior of asphalt concrete. The primary objective of this study is to validate the model under thermal loading conditions that are distinctively different from the mechanical loading conditions used in the model development. TSRST tests were conducted at the FHWA Turner-Fairbank Highway Research Center using three different cooling rates. The analysis was carried out using the linear viscoelastic model (without considering the cracking damage), the viscoelastic continuum damage (VECD) model, and the viscoelastoplastic continuum damage (VEPCD) model. Although VP behavior is a typical response in AC at high temperatures; however, it is the slow strain rate observed in thermal cracking that triggers VP response based on the t-T superposition principle. The predicted values of the fracture parameters in the TSRST tests were compared to the measured values to evaluate any increase in the accuracy that the higher level model would yield. The comparison confirmed: (1) the ability of the VEPCD model to accurately characterize the tensile behavior of asphalt concrete, whether the loading is mechanical or thermally-induced; and (2) a decrease in the accuracy of prediction as the complexity of the model decreases.


Draft: July 29, 2003

ROAD MAP FOR MITIGATING NATIONAL MOISTURE SENSITIVITY CONCERNS IN

HOT MIX PAVEMENTS

By

R. Gary Hicks MACTEC E & C, Sacramento, CA

[email protected]

Rita B. Leahy MACTEC E & C, Sacramento, CA

[email protected]

Michael Cook California DOT, Sacramento, CA

[email protected]

James S, Moulthrop Fugro-BRE, Austin TX [email protected]

and

Joe Button

Texas A & M University, College Station TX [email protected]

ABSTRACT One of the charges of the national seminar on moisture sensitivity held in San Diego on February 4-6, 2003 was to develop an outline for a road map for addressing the national concern of moisture sensitivity. This paper presents a document based on that outline that is included in the proceedings of the seminar. The Transportation Research Board (TRB) will publish the full proceedings from the national seminar in late 2003. Implementation of the findings, best practices, and research needs resulting from this seminar are expected to be discussed by the various committees within the TRB section on bituminous materials and at the AASHTO subcommittee on Materials.


Draft: July 29, 2003

1.0 INTRODUCTION 1.1 Background There cannot be a Road Map to address the national issues related to moisture sensitivity in hot mix asphalt pavements (HMA) without a vision, a mission, goals and associated work tasks. As such, selected members of the national seminar steering committee have developed the following descriptions for each of these items;

• Vision: Eliminate moisture sensitivity distresses in HMA pavements • Mission: Provide the necessary tools to practitioners that can be used to

eliminate moisture sensitivity in HMA pavements • Tasks: Identify the best practices, gaps in the knowledge and research needs

to address moisture sensitivity in HMA pavements. 1.2 Need for a Road Map

Moisture sensitivity in HMA pavements is one of the leading pavement performance related issues facing highway agencies. Most agree that the current test protocols for identifying moisture sensitive mixtures do not accurately predict field performance. A recent survey dated August 2002 of the state highways agencies, the FHWA federal lands offices and selected Canadian provinces indicated that 45 of the 55 agencies responding identified a moisture related problem in their HMA pavements and they specify some type of treatment to mitigate the problem. Over 50 % use a liquid anti-strip agent, 30 % use lime, and the remainder use one or the other. Forty-eight of the 55 agencies perform a test on the mix at some stage of the mix design and construction process to determine the need for an anti-strip agent. The types of tests include indirect tensile tests (AASHTO T-283, ASTM D-4867), compressive strength tests (AASHTO T-165), and wheel tracking in combination with the tensile test. Slightly over 60 % test for moisture damage during the mix design phase while the remainder test during the mix design and/or construction phases of the project. Though considerable work has been done over the past 50 years to solve the problem of moisture sensitivity in HMA pavements, there is still no agreement on a solution to mitigating the problem. As a result, the road map that is presented in this document is expected to provide direction to the pavement community in solving the moisture sensitivity problem.


The Use of a Performance-Based Fracture Criterion for the Evaluation of Moisture Susceptibility in Hot Mix Asphalt

Bjorn Birgisson

(Corresponding Author)

Assistant Professor Department of Civil and Coastal Engineering

University of Florida, 365 Weil Hall, P. O. Box 116580 Gainesville, FL 32611-6580

Tel: (352) 392-9537 ext. 1462 Fax: (352) 392-3394


Reynaldo Roque

Professor Department of Civil and Coastal Engineering

University of Florida, 365 Weil Hall, P. O. Box 116580 Gainesville, FL 32611-6580

Tel: (352) 392-9537 ext. 1458 Fax: (352) 392-3394


Gale C. Page

State Bituminous Materials Engineer Florida Department of Transportation

State Materials Office 2006 NE Waldo Road Gainesville, FL 32609

Tel: (352) 337-3100 Fax: (352) 334-1648


Submitted For Presentation and Publication at the 2004 Annual Transportation Research Board Meeting, Washington, D.C. Revised on Nov. 14, 2003. Number of words: Abstract = 242; Manuscript Text = 3,538; Number of tables: 4(1,000); figures: 7(7x250=1,750), Total = 6,530.


Birgisson, Roque, Page 2

Abstract. The laboratory testing procedures currently available for testing Hot Mix Asphalt (HMA) moisture susceptibility all evaluate the effects of moisture damage in the laboratory by measuring the relative change of a single parameter before and after conditioning (i.e., Tensile Strength Ratio, Resilient Modulus Ratio). The use of a single parameter to evaluate moisture damage must be questioned. Rather, a single unified framework that accounts for changes in key mixture properties is needed to effectively evaluate the effects of moisture damage in mixtures. This paper evaluates the use of a new performance-based fracture parameter, the Energy Ratio (ER) for quantifying the effects of moisture damage on the fracture resistance of mixtures. The Energy Ratio is used to determine the effects of moisture damage on changes in the fracture resistance of six granite mixtures that were prepared with and without the use of an antistripping additive. The granite aggregate used is a known stripping aggregate. In addition, one limestone mixture with a known high resistance to stripping was also used. The results presented show that not only is the Energy Ratio capable of detecting the effects of moisture damage on the fracture resistance of mixtures, it is also shown to detect the presence of antistripping agents in mixtures. Based on the results presented, the Energy Ratio may form the basis of a promising combined performance-based fracture criterion for evaluating the effects of moisture damage in mixtures as well as the overall resistance to fracture.

Keywords: moisture damage, hot mix asphalt, fracture mechanics, performance-based specification criterion.


Sangpetngam, Birgisson, Roque 1

A Multi-Layer Boundary Element Method for the Evaluation of Top-Down Cracking in Hot Mix Asphalt Pavements

by Boonchai Sangpetngam, Bjorn Birgisson, Reynaldo Roque Boonchai Sangpetngam Geotechnical and Material Engineer Dynamic Engineering Consultants Co., Ltd. SEATEC Group, 281 Soi Phanit Anan, Sukhumvit 71 Bangkok 10150 THAILAND Tel: 66-2-713-3888 Fax: 66-2-713-3889 Email: [email protected] Bjorn Birgisson (Corresponding Author) Assistant Professor Department of Civil and Coastal Engineering University of Florida, 345 Weil Hall, P. O. Box 116580 Gainesville, FL 32611-6580 Tel: (352) 392-9537 ext. 1462 Fax: (352) 392-3394 Email: [email protected] Reynaldo Roque Professor Department of Civil Engineering, University of Florida 345 Weil Hall, P. O. Box 116580 Gainesville, FL 32611-6580 Tel: (352) 392-9537 ext. 1458 Fax: (352) 392-3394 Email: [email protected]

Submitted For Presentation and Publication at the 2004 Annual Transportation Research Board Meeting, Washington, D.C. Revised on Nov. 14, 2003. Number of words: Abstract= 230, Manuscript: Text= 3,647, tables: (3x250)=750, figures: (11x250)=2750, Total = 7,377.


Sangpetngam, Birgisson, Roque 2

Abstract. Cracking in hot-mix asphalt pavements (HMA) is a major mode of premature failure. Recent work at the University of Florida has led to the development of a new viscoelastic fracture mechanics-based crack growth law entitled “HMA Fracture Mechanics” that is capable of fully describing both initiation and propagation of cracks in asphalt mixtures. The successful simulations of crack growth for generalized pavement conditions depend largely on how well the state of stress can be predicted in and around existing cracks in pavements. Previous work by Sangpetngam, Birgisson, and Roque (2, 3) has focused on the adaptation of a displacement discontinuity boundary element method for predicting stresses in the SuperPave IDT test, which then were subsequently used to predict the crack initiation and crack growth in simulated IDT tests using HMA fracture mechanics. This paper presents an extension of the previous displacement discontinuity boundary element formulation into layered materials. Homogeneous layers are stitched together numerically in “welded” contact. The ability of the new numerical for-mulation to model the effects of temperature-induced stiffness gradients on tensile stresses at the top of two cracked pavement sections in Florida. These pavement sections were modeled with and without temperature induced stiff-ness gradients. The introduction of stiffness gradients into the HMA layer is shown to increase the magnitude of tensile stresses at the top of the pavement, which is consistent with previous observations by Myers (4). Key words: pavement cracking, hot mix asphalt, displacement discontinuity method, modeling, top-down cracking, stiffness gradient. BACKGROUND

Cracking has long been accepted as a major mode of premature failure in asphalt concrete pavements. Unfortunately, the complexity of crack propagation in hot mix asphalt mixtures has been an obstacle to the incorpo-ration of fracture mechanics-based approaches in the bituminous pavement area. Improvements in the cracking resistance of mixtures require an understanding of how and where cracks initiate and coalesce into larger cracks all the way to failure.

This paper presents a displacement discontinuity boundary element method that is capable of accounting for the presence of cracks in layered flexible pavements. The DDM method provides an attractive alternative to finite element-based methods for modeling crack initiation and crack growth (2, 3). The DDM method requires meshes only on the boundaries of the pavement, including cracks (1,2, 3). Crack growth is addressed by adding more elements in regions of crack growth. Previous work by Sangpetngam, Birgisson, and Roque (3) has focused on the adaptation of a DDM method for predicting stresses in the SuperPave IDT test, which then were subsequently used to predict the crack initiation and crack growth in simulated IDT tests using HMA fracture mechanics. This paper presents a multi-layer extension to the DDM method presented by Sangpetgnam, Birgisson, and Roque (3). Homogeneous layers are stitched together numerically in “welded” contact. The new numerical formulation is used to predict maximum surface tensile stresses in two cracked pavement sections in Florida with known cracking performance. The ability of the DDM method to model the effects of temperature-induced stiffness gradients on tensile stresses at the top of two cracked pavement sections in Florida is demonstrated. As expected, the introduction of stiffness gradients into the HMA layer is shown to increase the magnitude of tensile stresses at the top of the pavement, which is consistent with previous observations by Myers (4). Finally, it is anticipated that the DDM method presented will be integrated into a pavement analysis tool that can be used within a mechanistic-empirical pavement design framework that is capable of predicting crack initiation and rate of crack growth in an efficient manner. OBJECTIVES

The primary objective of this paper is to describe a new multi-layer boundary element formulation that is based on the displacement discontinuity boundary element method. The displacement discontinuity method is reviewed briefly, followed by a description of the multi-layer formulation used. A second objective is to demonstrate how the resulting formulation can capture the effects of observed temperature-induced stiffness gradients in two pavement sections of known cracking performance. SCOPE

In the following, the displacement discontinuity boundary element method will be described briefly, followed by a description of the multi-layer formulation used. The multi-layer displacement discontinuity method will then be used to simulate stress states in two field sections with known top-down cracking performance. Each pavement section will be modeled with and without observed temperature-induced stiffness gradients. Finally, conclusions


Novak, Birgisson, Roque, and Choubane 1

Effects of One-Way and Two-Way Directional Heavy Vehicle Simulator Loading on Rutting in Hot Mix Asphalt Pavements

Marc Novak University of Florida Graduate Student Department of Civil and Coastal Engineering P.O. Box 116580 Gainesville, FL 32611-6580 Telephone: (352) 392-9537 Fax: (352) 392-3394 E-mail: [email protected] Dr. Bjorn Birgisson (Corresponding Author) University of Florida Assistant Professor Department of Civil and Coastal Engineering P.O. Box 116580 Gainesville, FL 32611-6580 Telephone: (352) 392-9537 Fax: (352) 392-3394 E-mail: [email protected] Dr. Reynaldo Roque Professor Department of Civil Engineering, University of Florida 345 Weil Hall, P. O. Box 116580 Gainesville, FL 32611-6580 Tel: (352) 392-9537 ext. 1458 Fax: (352) 392-3394 Email: [email protected] Dr. Bouzid Choubane Florida Dept. of Transportation Materials Research Park 5007 N.E. 39th Avenue Gainesville, FL 32609 Phone: (352) 955-6302 Fax: (352) 955-6345 E-mail: [email protected] Word Count: 7160 words [abstract (170) + text (3740) plus 4 tables and 9 figures] Revised Nov 14, 2004 for January 2004 TRB Annual Meeting and Subsequent Publication


Novak, Birgisson, Roque, and Choubane

2

Abstract. Instability rutting generally occurs within the top five centimeters (two inches) of the asphalt layer when the structural properties of the asphalt concrete are inadequate to resist the stresses imposed upon it. It is generally believed that near-surface transverse shear stresses perpetuate instability rutting. Field observations of Heavy Vehicle Simulator (HVS) testing noted greater rutting in one-way directional loading compared to two-way direc-tional loading, even at lower temperatures and with longer rest periods between load applications. An analysis of stress states in the asphalt pavement layer using the three-dimensional finite element commercial code ADINA showed that longitudinal stress path patterns varied between the different directional loadings. A hypothesis was developed that the differences in longitudinal plane stress path patterns between one-way and two-way directional loading attributed to the different levels of rutting. A visco-elastic model with load applications simulating the different directional loadings was constructed and used to test this hypothesis. The visco-elastic model results indicated qualitatively that even with greater relaxation times, one-way directional loading produces greater strains. Keywords: Instability Rutting, Heavy Vehicle Simulator, Finite Element Analysis, Stress Path Patterns


EFFECTS OF ASPHALT AGING ON HOT-MIX ASPHALT DIELECTRIC CONSTANT

Imad L. Al-Qadi

Charles E. Via, Jr. Professor of Civil and Environmental Engineering Via Department of Civil and Environmental Engineering

Leader of the Roadway Infrastructure Group Virginia Tech Transportation Institute

200 Patton Hall Blacksburg, VA 24061 Email: [email protected]

Phone: 540 231-5262; Fax: 540 231-7532

Samer Lahouar Senior Research Associate

Virginia Tech Transportation Institute 3500 Transportation Research Plaza

Blacksburg, VA 24061-0536 Email: [email protected]

Phone: 540 231-1504, Fax: 540 231-1555

Kun Jiang Graduate Research Assistant

Virginia Tech Transportation Institute 3500 Transportation Research Plaza

Blacksburg, VA 24061-0536 Email: [email protected]

Phone: 540 231-1588, Fax: 540 231-1555

Thomas E. Freeman Senior Research Scientist

Virginia Transportation Research Council, VDOT 530 Edgemont Road

Charlottesville, VA 22903 Email: [email protected]

Phone: 434 293-1957, Fax: 434 823-7978

TRANSPORTATION

INSTITUTE


Al-Qadi, Lahouar, Jiang, and Freeman 1

Effects of Asphalt Aging on Hot-Mix Asphalt Dielectric Constant

Imad L. Al-Qadi, Samer Lahouar, Kun Jiang, and Thomas E. Freeman

ABSTRACT

In this paper, in-situ dielectric constant variations of various hot-mix asphalt (HMA) layers versus time were studied. The dielectric constant of the considered HMA layers were nondestructively estimated using ground penetrating radar (GPR) data collected over a controlled pavement test facility: the Virginia Smart Road. It was found that the dielectric constant of various HMA layers decreased linearly with time but remained within the typical limits. For all tested HMA types, the variation slope was relatively small, with a maximum decrease of approximately 0.8 over a one year period. The main cause of the HMA dielectric constant decrease versus time was found to be the aging of the asphalt binder, which causes the reduction of its susceptibility to be polarized by the applied electric fields, thus decreasing its ability to store electric energy.

INTRODUCTION

Estimating the dielectric properties of materials is very important for many nondestructive evaluation techniques. In fact, the dielectric constant of construction materials can usually be correlated to their volumetric properties and can, therefore, be used as an indication of defects or distresses within the tested structure. For hot-mix asphalt (HMA) materials, the dielectric constant can usually be correlated to the density, air voids, asphalt content, and moisture accumulation (1). For concrete, the dielectric constant can be correlated to the aggregate type, cement-to- water ratio, and chloride content (2).

Since ground-penetrating radar (GPR) signals are affected by the dielectric properties of the materials through which the GPR electromagnetic (EM) waves propagate, estimation of the dielectric properties of construction materials is necessary for correct GPR data interpretation. For pavements, the main application of GPR is to nondestructively estimate the thicknesses of the different layers composing the pavement system. This information is usually needed as input for other nondestructive techniques, such as evaluating the structural capacity of pavements using falling weight deflectometer (FWD). The predicted layer thicknesses are used as input for the backcalculation models. Knowing the pavement layer thicknesses is also very important for a sound pavement management system (PMS). Different researchers have investigated GPR’s success in determining pavement thicknesses (3-5).

Several studies measured and reported the dielectric properties of HMA on laboratory samples. Al-Qadi (6) studied the dielectric properties of HMA in the frequency range of 12.4 to 18.0 GHz, using a set consisting of a focused conical horn antenna and an HP 8510B network analyzer. Results indicated that for dry HMA specimens, the real part of the dielectric constant ranged from 3.7 to 5.2, while the imaginary part ranged from 0.05 to 0.16. For wet HMA specimens (volumetric water content ranging from 1.2% to 8.2%), the real part of the dielectric constant varied from 4.1 to 5.3, and the imaginary part varied from 0.10 to 0.30. In another study, Shang et al. (7) used a coaxial apparatus to measure the dielectric properties of HMA over the frequency range of 0.1 MHz to 1.5 GHz. Results indicated that asphalt content and mix type did not significantly affect the measured complex dielectric constant. However, moisture content was found to be a predominant factor. The average measured real part of the complex dielectric constant over the frequency range of 8 to 900 MHz was 6.00 ± 0.15 for the dry specimens and 6.52 ± 0.99 for the soaked specimens. Using GPR to characterize the in-situ dielectric properties of the SM-12.5D SuperPaveTM HMA versus frequency was studied by Al-Qadi and his co-researchers (8). In their study, the authors found that both the real and imaginary parts of the complex dielectric constant of SM-12.5D vary with frequency within the GPR bandwidth.

This paper examines the variations of the in-situ dielectric properties of HMA versus time. In particular, the effect of asphalt-binder aging on the dielectric properties of various HMA mixes is investigated. For this study, the in-situ dielectric constants of the considered layers were nondestructively estimated using GPR.


1

Pavement Surface Friction Test Using Standard Smooth Tire: The Indiana Experience

by

Shuo Li, Ph.D., PE, Research Engineer

INDOT, Division of Research 1205 Montgomery Street

West Lafayette, Indiana 47906 Tel.: (765) 463-1521 [email protected]

Karen Zhu, Ph.D., Senior System Analyst INDOT, Division of Research

1205 Montgomery Street West Lafayette, Indiana 47906

Tel.: (765) 463-1521 [email protected]

Samy Noureldin, Ph.D., PE, Section Manager INDOT, Division of Research



and

Daehyeon Kim, Ph.D., PE, Research Engineer INDOT, Division of Research



Length of Paper: 7366 words

July 23, 2003


2

ABSTRACT This paper presents the seven-years experience of the Indiana Department of Transportation (INDOT) in the network pavement friction testing with the standard smooth tire. ABAQUS/Explicit was employed to simulate the tire-pavement friction phenomenon in terms of the viscous energy dissipation. Tremendous friction data was measured on the INDOT friction test track and highway pavements. It was found that the friction differences between the smooth and ribbed tires arise from the horizontal forces and vary with the pavement surface features. In general, the friction number with the ribbed tire is greater than that with the smooth tire. The differences remain consistent regardless of the test season. As pavement surface becomes rougher, the difference decreases and becomes insignificant on very rough pavement surface.

Friction seasonal variations are random and negligible. As the air temperature increases the friction number does not necessarily decrease. Applying seasonal correction based solely on the air temperature can not guarantee a better friction measurement. Correlation existed between wet-pavement accidents and network pavement friction condition but was not significant. INDOT established a uniform minimum friction requirement of 20 for the standard smooth tire at 64 km/h (40 mph). It was indicated that by the seven-years friction measurements, this friction requirement can guarantee a reasonable and consistent friction performance for INDOT network pavement.


Paper No. 03xxxx

TITLE:

WHY DO WE NEED TO CHANGE G*/SINδ AND HOW?

Number of words = 5407 (text)

AUTHORS: Rodrigo Delgadillo Kitae Nam Hussain Bahia

The Asphalt Pavement Research Group Department of Civil and Environmental Engineering The University of Wisconsin – Madison 2210 Engineering Hall 1415 Engineering Dr. Madison WI, 53706 (608) 265-4481 [email protected], [email protected], or [email protected]

Paper submitted for presentation and publication at the

Transportation Research Board 83 rd Annual Meeting January 11-15, 2004

Washington, D.C.


1

ABSTRACT

A number of State Highway Agencies claim that the Superpave specification has some critical gaps, most of them related to the performance characterization of modified binders [1]. Recognizing this fact AASHTO sponsored project NCHRP 9-10 and in 2001 NCHRP 459 [2] report was published. The report offered a revised system for testing and evaluating asphalt binders based on damage behavior. A scheme to conduct binder rutting test that would allow a more direct qualification of binders for specific climate and traffic conditions was presented. The proposal, however, was only conceptual and lacked the details required for implementation, such as specific criteria and limits.

This paper addresses the implementation of NCHRP 9-10 for binder rutting resistance. It reviews why G*/sinδ has to be changed for a new parameter, called viscous component of the creep stiffness Gv. It is shown how a mechanistic system based on damage behavior can be transformed in a new rutting specification. A proposal for specification limits in terms of the new Gv parameter is given. To develop the proposal, 19 asphalts of several grades currently used or marketed in Wisconsin were tested. The results of the binder testing were correlated with field performance using the past experience in the state of Wisconsin. The proposed limits are tentative and are mainly based on the ranking of the PG graded binders included in the study. The trial specification limits presented represent one step forward from the existing PG grading system towards a more reliable binder rutting characterization.

Key Words: Asphalt binders, specification limits, binder rutting, dynamic shear rheometer, damage characterization, mechanistic approach.


Analysis of Multivariate Models to Evaluate Segregation in Hot-Mix Asphalt Pavements

Paper 04-3502

By

Jun-Xia Wu Graduate Research Assistant

The University of Utah Department of Civil and Environmental Engineering

122 South Central Campus Drive, Suite 104 Salt Lake City, UT 84112

and

Pedro Romero, Ph.D., P.E

Assistant Professor The University of Utah

Department of Civil and Environmental Engineering 122 South Central Campus Drive, Suite 104

Salt Lake City, UT 84112 Ph: 801-587-7725 Fax: 801-585-5477

e-mail: [email protected]

Words 4,125 Tables 6* 250 1,500 Figures 2* 250 500 Total 6,125

Submitted for presentation and publication at the 2004 Annual Meeting of The Transportation Research Board

Original Document: July 30, 2003 Last Revision: November 14, 2003


Wu and Romero, Paper 04-3502 2

Analysis of Multivariate Models to Evaluate Segregation in Hot-Mix Asphalt Pavements

ABSTRACT Multivariate statistical techniques were used to determine the feasibility of quantifying segregation in hot-mix asphalt (HMA) pavements. This paper involves the analysis of data obtained at nine different field sites as reported by the National Center for Asphalt Technology (NACT) using visual ratings of segregation, nuclear density gauge readings, and laboratory tests.

Data were screened before multivariate statistical analyses were performed to

develop relationships among segregation level, change in key mixture properties (air voids, asphalt content, and percent passing various sieves), and change in mixture density. The results revealed that segregation level cannot be accurately identified by visual ratings and that multivariate statistics is more appropriate to evaluate segregation level based on actual measured properties. Laboratory prepared samples were made to assess the accuracy of the model developed in this study. The verification results indicated that the model can predict segregation level of these samples with good accuracy. Based on the analysis of the models, it was concluded that change in mixture density has the potential to predict segregation. This will give the ability to screen segregated pavement sections based on numerical field measurements instead of relying on subjective visual observations.

Given the promising results from this work, further studies on segregation models

based on density measurements are suggested. KEY WORDS Multivariate statistical analysis, statistical models, segregation, material properties, pavement density, nuclear gauge


EVALUATION OF SIMPLE PERFORMANCE TESTS

ON HMA MIXTURES FROM THE SOUTH CENTRAL UNITED STATES

Date of submission: July30, 2003 Word count: Abstract = 202 (Max = 250) Total paper including abstract, reference, text and tables = 7204 (Max = 7500) Authors: Amit Bhasin, Graduate Research Assistant Joe W. Button, Senior Research Engineer Arif Chowdhury, Associate Transportation Researcher Affiliations: Texas Transportation Institute Texas A&M University, College Station, Texas 77843-3135 Addresses: Texas Transportation Institute Texas A&M University, College Station, Texas 77843-3135 Phone, Fax, e-mail: 979/845-9965, 979/845-0278, [email protected]


2

ABSTRACT Since the development of the Superpave mix design procedure under the Strategic Highway Research Program (SHRP) about a decade ago, there has been a need to develop some type of a simple physical test to compliment the level 1 volumetric mixture design procedure. NCHRP Project 9-19 recognized the dynamic modulus test along with the flow time and flow number tests as the top three candidates for a simple performance test that could identify mixtures susceptible to permanent deformation.

Presented is a critical evaluation of these three tests along with the Superpave shear test - frequency sweep at constant height (SST-FSCH) with the Asphalt Pavement Analyzer (APA) as the torture test to identify mixes susceptible to permanent deformation. The Hamburg wheel-tracking device (HWTD) was also conducted on selected mixtures. Special laboratory HMA mixes designed to exhibit low dynamic modulus but high recovery of strains were also included in this evaluation. Results indicate that flow number value and flow time slope correlated better with laboratory rutting (APA and HWTD) than dynamic modulus. Flow number value, flow time slope, E*/sin φ at 1 Hz, flow number slope, and flow time value were among the best five correlations both with the APA and HWTD rut depths.


Wegman, Dahlberg, Bray, Lukanen, and Thomas 1

A Strong but Flexible Foundation for Chisago County

*Dan Wegman, Koch Pavement Solutions, Junction Hwy 52 & 55, P O Box 64596, St. Paul, MN 55164,[email protected]

Mic Dahlberg, Chisago County, 313 N. Main Street - Room 400, Center City MN 55012,

[email protected]

Ron Bray, WSB and Associates, 4150 Olson Memorial Highway, Suite 300, Minneapolis, MN 55422, [email protected]

Erland Lukanen, ERES Consultants, 251 Reid Lane South St. Paul, MN 55075,

[email protected]

Todd Thomas, Koch Pavement Solutions, 4027 E. 37th St North, Wichita, Kansas 67220, [email protected]

Word Count 4453 words

3 tables = 3 x 250 = 750 words 7 figures = 7 x 250 = 1750

Total = 6953 words


Wegman, Dahlberg, Bray, Lukanen, and Thomas 2

A Strong but Flexible Foundation for Chisago County

Dan Wegman1, Mic Dahlberg2, Ron Bray3, Erland Lukanen4 and Todd Thomas5

ABSTRACT Chisago County, Minnesota, like many other counties in the U.S., has a limited budget and many miles of gravel roads that need ever increasing expenditures to maintain their current condition. Paving would greatly increase the value of this infrastructure to both road owner and road users. However, conventional design and construction methods are too expensive or do not give the needed performance. A team of the county engineer, consultants, a supplier and a contractor developed a cost-effective method for upgrading Chisago’s granular material roads and reducing maintenance costs. The existing gravel road is analyzed and sampled. An emulsion stabilized base mix is designed using performance-related techniques adapted for emulsion mixes. Structural design is performed with traffic, soil and falling weight deflectometer data. The existing gravel is mixed with an asphalt emulsion formulated for optimal coating and curing as well as the desired strength and resistance to thermal cracking. After construction, the newly stabilized base is overlaid with a thin, specially engineered surface mixture or sealed with a chip seal to protect the stabilized base from moisture and to improve surface texture. Stabilizing a granular base strengthens it and makes it more consistent. A project using this method constructed in 2001 was followed by nine more projects in 2002. The initial project described in this study showed a 40 percent improvement in granular equivalency (GE) of the base. The result was a new, engineered system for a strong but flexible bituminous base and surface, ready for possible future staged construction when warranted. This paper discusses the design procedure, construction, laboratory test results, costs and field performance measurements, including structural calculations.

INTRODUCTION One of the biggest problems facing most road owners is the lack of sufficient funding to maintain all the roads in their system. (1) Chisago County Minnesota, like many other counties in the U.S., has both a limited budget and miles of gravel roads they spend money on each year just to maintain their current condition. The county, located 40 miles northeast of Minneapolis-St. Paul, was faced with periodic grading, re-profiling, adding gravel, and spraying these roads with dust control agents. Paving these roads would eliminate dust problems, protect the existing pavement structure, and increase property values, thus providing economic benefits for both the agency and the road users. (2) Several agencies have developed recommendations for improvements to unpaved roads. For example, the Iowa Department of Transportation calculates that paving a gravel road with 300 to 400 vehicles per day is economically viable, while the break even traffic level is 100 VPD. (3) The Vermont Local Roads Program recommends considering paving gravel roads when the traffic level reaches 50 VPD, and seriously considering it at 400 VPD. Further, it recommends the use of staged construction. (4) The Kentucky Transportation Cabinet agrees with Vermont, and concludes that gravel roads are more expensive to drive primarily because of higher vehicle maintenance costs. (5) When a road needs surfacing, the most common fix is applying a hot mix asphalt (HMA) overlay. Simply paving the existing gravel surfaces meets some of the objectives; however, without some strengthening of the existing foundation, it would be an invitation for premature failure of the pavement surfacing. Unfortunately the cost of building a structurally sound road by sub-cutting base inadequacies and realignment and placing a thick pavement structure of an 8.9 to 10.2 cm (3.5 to 4 in) asphalt wearing course is just too big a strain on the county’s budget. Thick overlays require ditch slope corrections and at times substantial grading in order to meet

1 Koch Pavement Solutions, Junction Hwy 52 & 55, P O Box 64596, St. Paul, MN 55164, (651)480-3821, Fax: (651)480-3874,[email protected] 2 Chisago County, 313 N. Main Street - Room 400, Center City MN 55012, (651)-213-0708, Fax: (651)213-0772, [email protected] 3 WSB and Associates, 4150 Olson Memorial Highway, Suite 300, Minneapolis, MN 55422, 763-541-4800, Fax: 763-541-1700, [email protected] 4 ERES Consultants, 251 Reid Lane South St. Paul, MN 55075, (651) 453-2080, Fax: (651) 453-2081, [email protected] 5 Koch Pavement Solutions, 4027 E. 37th St North, Wichita, Kansas 67220, (316)828-6737, Fax: (316)828-7385, [email protected]




Title: “Identification of Hot Mix Asphalt Permanent Deformation Parameters Using Triaxial Strength Tests and a Microstructure-Based Viscoplastic Continuum Model” Authors: Laith Tashman1, Eyad Masad2, Dallas Little3, and Hussein Zbib4

1 Graduate Research Assistant, E-mail: [email protected], Tel: 979-458-0893, Fax: 979-845-0278

2 Assistant Professor, E-mail: [email protected], Tel: 979-845-8308, Fax: 979-845-0278

3 Professor E-mail: [email protected], Tel: 979-845-9847, Fax: 979-845-9356

Texas Transportation Institute Texas A&M University 3135 TAMU College Station, TX 77843-3135 4Professor, E-mail: [email protected], Tel: 509-335-7832, School of Mechanical and Material Engineering Washington State University Pullman, WA 99164


Number of words=(4837 WORDS + 0 Table@250 + 10 Figures@250) = 7337


Tashman et al. 2

ABSTRACT Complex interactions take place within the microstructure of Hot Mix Asphalt (HMA) due to the different length scales and material properties involved. One of the main challenges in modeling HMA is the ability to capture the manifestations of these interactions using a reasonable experimental program, a systematic analysis procedure, and a continuum model that accounts for the phenomena influencing performance.

This paper presents experimental and analytical methodologies to determine important material properties that influence HMA permanent deformation at high temperatures. This is achieved by analyzing data from compressive triaxial tests conducted at different confining pressures and strain rates within the framework of a non-associated microstructure-based viscoplastic continuum model. The model is developed to account for several phenomena known to influence HMA permanent deformation such as aggregate structure friction, aggregate structure dilation, confining pressure dependency, strain rate dependency, anisotropy, and microstructure damage following the mix hardening. The presented model is shown to account for these phenomena and match the experimental data fairly well. Keywords: viscoplastic, anisotropy, damage, continuum, Drucker-Prager, permanent deformation, asphalt concrete, microstructure, triaxial strength test.


VERIFICATION OF VCA TESTING TO DETERMINE STONE-ON-STONE CONTACT OF HMA MIXTURES

By

Donald E. Watson

(Corresponding Author) Research Engineer



E-Mail: [email protected]

Eyad Masad Assistant Professor

Department of Civil Engineering and Texas Transportation Institute

Texas A&M University College Station, TX 77843-3135

Tel: 979 845 8308 Fax: 979 845 0278

E-Mail:[email protected]

Kathryn Ann Moore, P.E. Graduate Research Assistant, Auburn University


Kevin Williams Research Engineer

National Center for Asphalt Technology E-mail: [email protected]

L. Allen Cooley, Jr.

Burns, Cooley, Dennis, Inc. (Formerly, National Center for Asphalt Technology)


Paper submitted for presentation and publication at the 2004 Annual Meeting of the

Transportation Research Board

Abstract = 236 Text = 4453 Tables/Figures (11 x 250) = 2750 Total Words = 7439


Watson, Masad, Moore, Williams, Cooley 1

VERIFICATION OF VCA TESTING TO DETERMINE STONE-ON-STONE CONTACT OF HMA MIXTURES

ABSTRACT During NCHRP 9-8, Designing Stone Matrix Asphalt Mixtures, the Voids in Coarse Aggregate (VCA) concept was selected as the preferred method to determine if stone-on-stone contact existed in stone matrix mixtures. It is believed that stone-on-stone contact is important for Open-Graded Friction Course (OGFC) mixes in order to minimize the potential for rutting. Therefore, the same VCA requirements were adopted for OGFC mixes as had been developed for Stone Matrix Asphalt mixtures.

The objective of this study was to verify the VCA concept for defining stone-on-stone contact within OGFC mixtures by utilizing digital imaging techniques such as analyzing particle contacts and the air void size distribution. The effect of aggregate breakdown on stone-on-stone contact by the VCA method was also evaluated. Conclusions made based on the information presented in this study are: (1) A general guideline for determining the critical breakpoint sieve would be to select the finest sieve for which there is at least 10 percent of the total aggregate retained. This sieve size should also differentiate between the aggregate skeleton and filler particles. (2) Digital imaging provides a scientific method for identifying when stone-on-stone contact exists and supports the VCA. An advantage of digital imaging is that it can quantify the number of contacts between aggregate particles.

Keywords: Open-Graded Friction Course, Superpave Gyratory Compactor, digital imaging, X-ray tomography, Voids in Coarse Aggregate


PAPER 04-3747

FIELD VALIDATION STUDY OF LOW-TEMPERATURE PERFORMANCE GRADING

TESTS FOR ASPHALT BINDERS

PAPER SUBMITTED FOR PRESENTATION AND PUBLICATION TRANSPORTATION RESEARCH BOARD

JANUARY 2004

Simon A.M. Hesp and Serban Iliuta, Department of Chemistry, Queen’s University,

Kingston, Ontario, K7L 3N6 Canada

Mihai O. Marasteanu, Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota, 55455-0116 USA

Tony Masliwec and Kai K. Tam, Bituminous Section, Materials Engineering and Research

Office, Ontario Ministry of Transportation, Downsview, Ontario, M3M 1J8 Canada WORD COUNT ABSTRACT: 234 WORDS IN TEXT: 5764 FIGURES: 1250 TABLE: 250 _____+ TOTAL: 7498


Hesp, Iliuta, Marasteanu, Masliwec and Tam – Paper 04-3747 Page 2

FIELD VALIDATION STUDY OF LOW-TEMPERATURE PERFORMANCE GRADING TESTS FOR ASPHALT BINDERS Simon A.M. Hesp and Serban Iliuta, Department of Chemistry, Queen’s University, Kingston, Ontario, K7L 3N6 Canada Mihai O. Marasteanu, Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota, 55455-0116 USA Tony Masliwec and Kai K. Tam, Bituminous Section, Materials Engineering and Research Office, Ontario Ministry of Transportation, Downsview, Ontario, M3M 1J8 Canada ABSTRACT This paper examines the effectiveness and/or deficiencies of current Performance Graded Asphalt Cement (PGAC) specification testing to predict low-temperature performance. The ability of various binder properties to predict cracking in the field is assessed from a total of 17 trial sections constructed in northern Ontario. The tests include the currently used bending beam rheometer and direct tension tests as well as a more fundamental fracture mechanics-based method. The results indicate that the currently used grading procedure does a reasonable job at predicting the ranking for most sections within each site but a poor job at the prediction of the onset of cracking. The need for improvement is illustrated with two sections on Highway 631, which were constructed in 1991 with binders of the same grade, but show a difference in transverse cracking severity of nearly a factor twenty. Furthermore, two sections on Highway 118, constructed in 1994 with binders of almost identical grade, are cracked by a more modest difference of 40 percent. Finally, the PG 58-28 and both of the PG 58-34 sections, as constructed in 1996 on Highway 17, which were exposed to minimum surface temperatures of -26.8°C in their first winter and -27.2°C in 2003, and hence should not have cracked, are damaged by a significant 169, 52 and 65 transverse cracks/km, respectively. Physical aging and notch sensitivity of the binders are indicated as major contributing factors for this early distress.


EVALUATION THE MOISTURE SENSITIVITY OF BITUMINOUS MIXTURES USING COMPLEX MODULUS APPROACH.

Authors : Eduardo Castañeda Pinzón Universidad Industrial de Santander, Colombia Professor, School of Civil Engineering Carrera 27 Calle 9 Bucaramanga, Colombia Tel. 57-6320744 Fax. 57-6320744

Christian Such Laboratoire Central des Ponts et Chaussées, France Division de Matériaux et Structures de Chaussées Route de Bouaye, 44341 Bouguenais Cedex, France Tel. 33-240845762 Fax. 33-240845994

Abstract. Various laboratory tests are used to evaluate the moisture sensitivity of bituminous mixtures. However, most of them are destructive and require a large number of specimens. Consequently, they do not permit continuous monitoring of the deterioration in mechanical performance or, still less, measurement of the recovery of this performance as water evaporates during the drying process. Monitoring of the stiffness modulus could provide a clearer picture of the process of deterioration and recovery that occurs during an immersion – drying cycle. However, during the specimen immersion phases, bitumen ages and hardens ; its stiffness modulus increases. Thus, the action of water simultaneously produces deterioration in the bitumen-aggregate bond and hardening of the binder; these two processes lead to opposing responses and prevent us from making a clear appraisal of the bituminous mixture’s ability to withstand the action of water. Evaluating the mechanical characteristics of bituminous mixtures using a Cole-Cole plot or in Black space provides new possibilities for isolating the effect of water at the bitumen-aggregate interface from the effect resulting from the binder.

INTRODUCTION

Pavements deteriorate under the combined effect of traffic and the climate, leading to premature expenditure because of the need for frequent maintenance. Water reduces the mechanical strength of bituminous mixtures and speeds up the rate at which the quality of service of pavements is lost. In the laboratory, the mechanical characteristics of the mix formulations used for pavement construction are evaluated using materials that have been dried beforehand. The tests that are performed to characterize the stiffness or fatigue strength of bituminous mixtures are performed on laboratory specimens, without taking any account of the possible presence of water which may modify the performance of the mixture during its service life.

The study presented in this paper describes a non destructive method for evaluating the effects of immersion and drying on the mechanical performance of a bituminous coated material. This work was conducted as part of doctoral research at Nantes University and conducted at the Laboratoire Central des Ponts et Chaussées.

EVALUATING THE EFFECT OF WATER

In bituminous mixtures water acts essentially at the aggregate-bitumen interface by impairing the bond between the two materials (1); drying, however, can reverse this process (2). Mix design studies for hot mixes feature tests which consider the effect of water either on the complete mix or on some of its components (3). Thus, passive adhesion is evaluated by immersing a specimen of bituminous mixture for a specified length of time and at a specified temperature and subsequently measuring the surface area that is still coated with bitumen. Among the most frequently used moisture sensitivity tests are the Duriez test or the test of compressive strength before and after immersion (4, 5) and the Lottman method or the Indirect Tensile Test (6).


Punith et al. 1

Characterization of Polymer and Fiber-Modified Porous Asphalt Mixtures Submission Date: 07/31/2003 Word Count: 6229 V.S. PUNITH, S. N. SURESHA, A. VEERARAGAVAN Centre for Transportation Engineering (CTE), Department of Civil Engineering, Bangalore University, Bangalore-560056, India. Dept Phone No: 091-080-3214001 Ext 267/264 Fax: 091-080-3218134 Email: [email protected] SRIDHAR RAJU, SUNIL BOSE Central Road Research Institute (CRRI), New Delhi-110020, India. Fax: 091-011-26845943 Email: [email protected]


Punith et al. 2

In view of the increasing vehicular intensity in India with regard to the impact of that on wet-weather accident rates due to skidding and poor visibility during rainy season, there is a requirement for an investigation into friction and drainage course as a surface layer. Friction course popularly known as porous asphalt or popcorn mix, which in recent years, has become popular in European countries, South Africa and in United States, for addressing environmental and safety needs was the best alternative. A research study focusing on the use and properties of porous asphalt mixtures containing reclaimed polyethylene modified binder (RPEB), crumb rubber modified binder (CRMB) and 60/70-grade binder with cellulose fibers was undertaken. In the present study, the relative performance of modified porous asphalt mixtures and an aspect relating to the design of such mixtures, based on the laboratory study has been presented. Laboratory tests were carried out on porous asphalt mixtures to determine the resistance to abrasion, moisture-induced damage, fatigue, plastic deformation and the coefficient of friction. The test results indicated that polymer-modification of the binder enhances the relevant engineering properties of the porous asphalt mixtures.


Romanoschi, Hossain, Gisi and Heitzmann

1

PAPER 04-3811

Accelerated Pavement Testing Evaluation of the Structural Contribution of Full-Depth Reclamation

Material when Stabilized with Foamed Asphalt

by

Stefan A. Romanoschi, Mustaque Hossain, Andrew Gisi and Michael Heitzmann

(4917 words + 1 table +9 figures = 7417 words)

November 2003 Stefan A. Romanoschi, Ph.D., P.E. Assistant Professor, Department of Civil Engineering, 2118 Fiedler Hall, Kansas State University, Manhattan, KS 66506. Ph: (785) 532-1594, Fax: (785) 532-7717, e-mail: [email protected] Mustaque Hossain, Ph.D., P.E. Professor, Department of Civil Engineering, 2118 Fiedler Hall, Kansas State University, Manhattan, KS 66506. Ph: (785) 532-1576, Fax: (785) 532-7717, e-mail: [email protected] Andrew Gisi, P.E. Geotechnical Engineer, Bureau of Materials and Research,

Kansas Department of Transportation, 2500 Van Buren St., Topeka, KS 66506. Ph: (785) 532-1594, Fax: (785) 532-7717, e-mail: [email protected]

Michael Heitzmann, P.E. Bituminous Materials Engineer, IADOT Central Materials

Laboratory, Ames, IA . Ph: (785) 532-1576, Fax: (785) 532-7717, e-mail: [email protected]


Romanoschi, Hossain, Gisi and Heitzmann

2

ABSTRACT The objective of this research was to determine the effectiveness of the use of foamed asphalt stabilized Recycled Asphalt Pavement from Full-Depth Reclamation (FAS-FDR) as base material for flexible pavements. The experiment, conducted at the Civil Engineering Infrastructure Systems Laboratory (CISL) of Kansas State University, consisted of constructing four pavements, one with a nine inch conventional Kansas AB-3 granular base and three with six, nine and 12 inches of FAS-FDR, and subjecting them to full-scale accelerated pavement test. All four pavements sections were loaded with 500,000 axle load repetitions, at room temperature and under moderate moisture levels in the subgrade soil. The measured stresses and strains as well as the permanent deformation (rutting) observed on the pavement sections indicated that FAS-FDR can be successfully used as a base material. The measured rut depths and compressive vertical stresses at the top of the subgrade suggest that one inch of FAS-FDR base shows performance equivalent to that of one-inch conventional Kansas AB-3 granular base. The effective structural number computed from the Falling Weight Deflectometer (FWD) tests on the as-constructed pavements showed that average structural layer coefficient for the FAS-FDR base material is 0.18.

ACKNOWLEDGEMENTS The research project was selected, designed and monitored by the members of the Midwest States Accelerated Pavement Testing Pooled Fund Technical Committee. The authors acknowledge the cooperation and supervision of all committee members in this study and Wirtgen GmbH for providing technical support and the foamed asphalt mixing plant.


THE EFFECT OF DIFFERENT AXLE CONFIGURATIONS ON THE FATIGUE LIFE OF AN ASPHALT CONCRETE MIXTURE

By

Karim Chatti, Ph.D. (Corresponding Author)

Assistant Professor Department of Civil and Environmental Engineering

Michigan State University 3546 Engineering Building

East Lansing, Michigan 48824 phone: 517-355-6534; fax: 517-432-1827


Chadi S. El Mohtar Former Graduate Student

Department of Civil and Environmental Engineering Michigan State University 3546 Engineering Building

East Lansing, Michigan 48824 email: [email protected]

prepared for presentation and publication

at the

2004 Annual Meeting of TRB Washington, D.C.

November 15, 2003

Text = 3663 words No. of figures =10x250 = 2500 word equivalents No. of tables = 4x250 = 1000 word equivalents

Total = 7163 word equivalents


mailto:[email protected]

Chatti and El Mohtar

ABSTRACT In this paper, the fatigue life of an asphalt mixture under different truck axle configurations was determined directly from the indirect tensile cyclic load test by using load pulses that are equivalent to the passage of an entire axle group or truck. The dissipated energy approach was adopted in analyzing the results and determining the number of repetitions to failure for each case, and a unique fatigue curve that can be used for multi-axle configurations was developed. Trucks consisting of up to eleven axles and axle groups of up to eight axles were studied. The results showed that the normalized damage per load carried decreases with increasing number of axles within an axle group. Additionally, the fatigue lives predicted using single load pulses were compared to the measured ones from the different axle groups and trucks.

ii


Detecting and Measuring Hot-Mix Asphalt Segregation Using High-Speed Texture Measurement

Kevin K. McGhee, P.E. Senior Research Scientist, Virginia Transportation Research Council 530 Edgemont Road Charlottesville, VA 22903 voice (434) 293-1956, fax (434) 293-1990 email: [email protected]

Gerardo W. Flintsch, Ph.D., P.E. (1) Associate Professor, The Via Department of Civil and Environmental Engineering Transportation Fellow, Virginia Tech Transportation Institute 200 Patton Hall, Virginia Polytechnic Institute and State University Blacksburg, VA 24061-0105 voice (540) 231 9748, fax (540) 231 7532 email: [email protected]

Edgar de León Graduate Research Assistant, Virginia Tech Transportation Institute 3500 Transportation Research Plaza Blacksburg, VA 24061-0105 voice (540) 231 1588, fax (540) 231 1555 email: [email protected]

Word Count: 3938 + 10 figures + 4 tables = 7438

(1) Corresponding author

Key words: Pavement segregation, macrotexture, uniformity, quality control, pavement surface characteristics.


McGhee, Flintsch, and de León

2

ABSTRACT

Segregation has long been one of the major problems in the production and placement of hot-mix asphalt (HMA). This paper discusses the application of high-speed texture measurement for detecting and quantifying segregation of HMA pavements. The described research attempts to apply the approach proposed in NCHRP Report 441, which builds on the ability to predict the expected non-segregated macrotexture using various mix properties. The foundation of this project was a series of field experiments designed to sample the uniformity of typical VDOT paving mixtures and to test the validity of available equations to predict target macrotexture values. Eight HMA mixes with variable maximum aggregate size and volumetric properties were considered. At each location, the research team conducted dynamic macrotexture measurements and selected the areas to conduct static tests based on those measurements. The static tests included the following: static macrotexture using a Circular Track Meter, density using nuclear and electromagnetic devices, and core extraction and testing. The laboratory tests performed on the cores included: core height (mm), Specific Gravity, void content, laboratory permeability, asphalt content, and gradation. The researchers demonstrated that macrotexture measurement holds great promise as a tool to detect and quantify segregation for quality-assurance purposes. Correlations of texture with void level/density and asphalt content (traditional measures of segregation) are strong, especially for mixes with moderately-sized aggregates. .


Determining Air Voids Content of Compacted SMA Mixtures

Hongbin Xie (Corresponding Author)

Graduate Research Assistant National Center for Asphalt Technology


Phone: (334) 844-6228 Fax: (334) 844-6248


Donald E. Watson Research Engineer




Submitted for presentation and publication at the 83rd Annual Meeting of the Transportation Research Board

Washington, D.C., January 2004 Abstract = 245 Figures/Tables (15 x 250) = 3750 Text = 3490 Total Words = 7485


Xie, Watson 1

Determining Air Voids Content of Compacted SMA Mixtures

Hongbin Xie and Donald E. Watson

ABSTRACT

This study compared the difference in air voids, optimum asphalt content and VMA using the SSD and CoreLok methods for determining Gmb. The critical air voids level at which SMA mixtures are considered to become permeable was also determined for the gradations used in this study.

Some of the pertinent conclusions are as follows: (1) There is a significant difference between air voids content measured by the SSD method and CoreLok method. (2) The CoreLok method resulted in a higher optimum asphalt content and VMA than designs based on the SSD method. (3) The CoreLok method was found to have a system error that overestimated the air voids content at zero to very low air void levels, therefore a correction factor was suggested to apply to the Corelok results. (4) At a permeability threshold of 125 ×10-5 cm/s, the critical air voids content are 4.5, 5.7 and 7.8 percent by the SSD method for 19, 12.5 and 9.5 mm NMAS SMA mixtures, respectively. (5) Both the SSD and corrected CoreLok methods can be used for SMA 9.5 mm NMAS mixtures. For SMA 12.5 mm NMAS mixtures with 6.0 percent or more air voids and for SMA 19 mm NMAS mixtures with more than 4 percent air voids, there is a greater potential for error by the SSD method and the corrected CoreLok method should be used.

Keywords: Stone Matrix Asphalt (SMA), Air Voids, Saturated Surface Dry (SSD), CoreLok, Voids in Mineral Aggregate (VMA), Permeability.


Paper No. 04-3974

TITLE:

Role of Modified Binders in Rheology and Damage Resistance Behavior of Asphalt Mixtures

AUTHORS:

Hamid R. Soleymani, Ph.D.1

Huachnun Zhai, Ph.D. 2 Hussain Bahia, Ph.D.3

1Department of Civil and Environmental Engineering

220 Civil Engineering Building University of Alberta, Edmonton, Canada, T6G 2G7

2Laboratory Manager

Idaho Asphalt Supply, Inc. P.O. Box 966

Nampa, Idaho 83653

3Department of Civil and Environmental Engineering The University of Wisconsin – Madison

2210 Engineering Hall, 1415 Engineering Dr. Madison WI, 53706

Word Counts = 4499

Paper submitted for presentation and publication at the Transportation Research Board

83rd Annual Meeting January 11–15, 2004

Washington, D.C.


Soleymani, Zhai, and Bahia,

1

ABSTRACT Rheological and damage characterization of asphalt mixture under dynamic loading, different frequencies, and temperatures can simulate wide range of traffic loads and climate conditions. Unfortunately, the characterization of asphalt mixtures with their rhelogical properties requires considerable time, financial resources, and equipment, elements that are not readily available to contactors and design engineers in most firms. Consequently, researchers have made significant attempts to estimate the dynamic properties of asphalt mixtures based on their binder and aggregate properties.

This study attempts to add to existing knowledge in the area of modified asphalt mixture by presenting data from 36 different mixtures produced from nine different modified binders, all of which were tested for their rheology, rutting, and their fatigue resistance. A set of simple models is offered to quantify the relationship between binder properties and mixture properties including G*, rutting, and fatigue life. It is shown that G* of modified mixtures could be represent by a simple power law function of G* of modified binders. For rutting rate, the change in the binder rutting rate of mixtures is approximately 20% that of binders. Also is shown that changing the fatigue life of binders by 100% can result in a 20% change in the fatigue life of mixtures. Although the relationships are not fundamental, and are entirely phenomenological, they provide good first approximation tools to quantify the effects of binders and thereby inform initial decisions regarding the importance of modified binders in pavement performance.

Key Words: Polymer Modified, Rheology, Complex Shear Modulus, Rut, Fatigue


Bertollo, Bernucci, Fernandes & Leite 1

Mechanical Properties of Asphalt Mixtures Using Recycled Tire Rubber Produced in Brazil - A Laboratory Evaluation Submission date: August 1, 2003 (Abstract: 213 words) (Text: 4844 words) (4 tables & 4 figures: 2000 word equivalents) Total: 7057 words Authors’ names: Sandra A. Margarido Bertollo, Liedi Bariani Bernucci, Jose Leomar Fernandes Jr. and Leni Mathias Leite Liedi Bariani Bernucci and Sandra A. Margarido Bertollo Affiliation: Department of Transportation – University of Sao Paulo Address: Av. Prof. Almeida Prado, Travessa 2, 83, 05508-900 - Sao Paulo, SP, Brazil Phone numbers: 55 (11) 3091-5213 / 3091-5485 Fax number: 55 (11) 3091-5716 E-mails: [email protected] and [email protected] Jose Leomar Fernandes Jr. Affiliation: Department of Transportation – Engineering School of Sao Carlos, University of Sao Paulo Address: Av. Trabalhador Sao-carlense, 400 – Centro, 13566-590 - Sao Carlos, SP, Brazil Phone number: 55 (16) 273-9598 Fax number: 55 (16) 273-9602 E-mails: [email protected] Leni Mathias Leite Affiliation: Petrobras – Brazilian Petroleum SA Address: CENPES – Centro de Pesquisas da Petrobras Ilha do Fundao Quadra 7 – Cidade Universitária, 91949-900 - Rio de Janeiro, RJ, Brazil Phone numbers: 55 (21) 3865-6736 Fax number: 55 (21) 3865-6771 E-mail: [email protected]


Bertollo, Bernucci, Fernandes & Leite 2

ABSTRACT This work presents the findings of a laboratory study that aimed to evaluate the effects of recycled tire rubber on the properties of dense asphalt mixtures. Three mix types, a conventional dense hot-mix asphalt concrete, a dry process rubber modified asphalt concrete, and a wet process asphalt-rubber, were included in the investigation. For the evaluation of mechanical properties, the asphalt mixtures were submitted to dynamic indirect tension tests for determining the resilient modulus, indirect tensile strength test, and resistance to rutting in a wheel-tracking device. The dense-graded mixes produced by both the wet and the dry process showed good laboratory performance. In both cases, the mixes presented reduction of resilient modulus in comparison with the conventional asphalt mixture, proving that the addition of rubber is an interesting alternative to increase the flexibility. The resistance to permanent deformation was improved when adding tire rubber. For the wet process, it was observed that the increase in asphalt content did not affect the rutting resistance, confirming the possibility of employing this technique as intermediate course or SAMI for reducing reflective cracking. The use of tire rubber in the asphalt paving industry could contribute to minimize the problems related to the disposal of waste tires and, at the same time, improve some engineering properties of asphalt mixtures.


Laboratory Study of Fatigue Characteristics of HMA Surface Mixtures Containing RAP

Baoshan Huang, Dept. of Civil and Env. Eng., The Univ. of Tennessee, Knoxville, TN 37996, [email protected] Brian K. Egan, Materials & Tests Division, TN Dept. of Transportation, 6601 Centennial Blvd, Nashville, TN 37243 William R. Kingery, Zhixiang Zhang and Gang Zuo, Dept. of Civil and Env. Eng., The Univ. of Tennessee, Knoxville, TN 37996. Abstract. The use reclaimed asphalt pavement (RAP) in flexible pavement surface layer has been a sensitive issue. One of the main concerns has been the fatigue resistance of these mixtures. This paper presents the preliminary findings of a laboratory study, in which the fatigue characteristics of hot-mix asphalt mixtures containing No. 4 sieve screened RAP were evaluated. A typical surface mixture commonly used in the state of Tennessee was evaluated at 0, 10, 20, and 30 percent of RAP content. Fatigue characteristics of mixtures were evaluated through indirect tensile strength, semi-circular bending (SCB) and semi-circular notched fracture resistance tests. Word count Abstract 98 Text 3351 Figure (14x250) 3500 Table (1x250) 250 Total 7051

INTRODUCTION

Reclaimed asphalt pavement (RAP) is a valuable resource in pavement construction. Unlike the crushed concrete, the possibility of utilizing the old asphalt binder in the newly blended mixtures, and therefore reducing the required (new) asphalt content, makes the use of RAP in HMA mixtures more economically attractive. As early as the 1930s, there were reports on the use of RAP in asphalt pavements [1]. Since the mid to late 1970s, with the ever increasing cost of raw materials and the awareness of environmental protection, the use of RAP has become more and more popular [2]. In spite of wide application of RAP materials today, however the use of RAP in major load carrying and surface layers of asphalt pavements has always been a sensitive issue. The main concerns about the use of RAP (especially in significant quantity) in surface or load carrying layers are the durability and long-term fatigue resistance of HMA mixtures with RAP materials. For this reason, most state DOT’s in the US either limit or restrict the use of RAP on the surface layer and limit the percentage use of RAP on the structural layers. Generally, the addition of RAP in the HMA mixtures will blend the long-term aged asphalt cement in the RAP with the fresh asphalt binder. The resulting asphalt cement in the mixtures tends to be stiffer. Generally such mixtures are not prone to rutting. The main concerns to such mixtures are their resistance to long-term fatigue cracking and moisture susceptibility.

OBJECTIVE

The objective of this paper was to analyze the fatigue characteristics of a Tennessee surface mixture with the inclusion of different percentages of No. 4 sieve screened RAP materials. The fatigue characteristics of the mixtures were evaluated through laboratory mixture performance tests. A typical surface mixture commonly used in the state of Tennessee was evaluated at 0, 10, 20, and 30 percent of RAP content. One type of aggregate (limestone) and an SBS polymer modified asphalt binder meeting Superpave specification for PG76-22 were considered in this paper.

MATERIALS

Asphalt Binder and Aggregates

The asphalt binder used in the preliminary study was an SBS polymer modified asphalt meeting the Superpave specification for PG76-22. The aggregates used in the mixtures included the coarse limestone “D-Rock”, No.10 soft limestone screening, natural sand, manufactured sand, and No. 4 sieve screened RAP. Figure 1a presents the laboratory verified aggregate gradations for each individual stockpiles and RAP. The verified asphalt content of the RAP material was 5.5 percent.


EFFECT OF AGING ON ASPHALT

CONCRETE MOISTURE DAMAGE

Pedro Castro-Fernandez, Ph.D. Candidate, PE

Professor, Civil Engineering Department,

University of Costa Rica

Víctor Cervantes – Calvo, PE

Highway Engineering Research, Civil Engineering Department,


Roy Barrantes – Jiménez, PE

Highway Engineering Research, Civil Engineering Department,


Vincent Blackamore – Barrantes, PE

Alumnus, Civil Engineering Department,


Escuela de Ingeniería Civil,

Ciudad Universitaria Rodrigo Facio,

Universidad de Costa Rica,

San Pedro de Montes de Oca,

San José, Costa Rica.

Tel. 011 – 506 – 207 – 4125

Fax. 011 – 506 – 207 – 4440

Email. [email protected]

Submission date: November 10st, 2003.

Word count: 7174


Castro-Fernández, Cervantes-Calvo, Barrantes-Jiménez, and Blackamore-Rodríguez 2

ABSTRACT

This research project was conducted in order to assess the effect of different techniques of asphalt binder

aging and asphalt concrete aging, on retained strength after a 24 hour 60°C conditioning period, as an indication of moisture damage susceptibility. Two different gradation curves (well graded dense and dense with bigger amounts of coarse aggregate and mineral dust), as well as two different additives (lime and a plastomer), were considered. Asphalt binder (AC-20) was used.

In regard to asphalt binder aging, thin film oven aging (TFO) has been applied, in order to simulate the critical aging an asphalt binder can go through in an actual plant operation (short term). In regard to hot mixed asphalt concrete aging, short term oven aging has been applied (oven curing before compaction), as well as long term oven aging (compacted samples are aged at 85°C for 5 days, after short term aging).

It has been found that the critical aging condition, in order to measure the least possible retained strength (smallest nominal strength and smallest percentage), is the short term oven aging technique. Additionally, it has been found that the relative benefit of additive application (lime or a plastomer) consists of an increased asphalt mastique (mix of asphalt binder and mineral dust) stiffness, very similar to what actually occurs after more severe levels of aging; it has also been found, nevertheless, that this increased stiffness takes place just when aging is lenient (TFO and STOA).

With aging, moisture damage susceptibility is reduced, due to an increase in asphalt binder cohesion, as well as to an increase in asphalt – aggregate adhesion. It is also concluded that the immersion – compression test considers the effect of asphalt – aggregate adhesion in a higher degree than the indirect tensile strength test. Immersion - compression is the most critical test to assess asphalt concrete moisture damage susceptibility (at least for the crushed igneous aggregate tested, on dense graded mixes, where it appears aggregate – asphalt binder adhesion is more relevant than asphalt binder cohesion).

Marshall mix design method, together with immersion-compression and indirect tensile retained strength

methods have been considered in order to judge actual testing techniques in Costa Rica. It was intended to gather valuable information in regard to development of new specifications on hot mix asphalt concrete. 1. INTRODUCTION The main purpose of this research project is to assess the effect of different laboratory aging techniques on retained strength (measured by immersion-compression and indirect tensile strength). In addition, the effect of a series of experimental factors on hot mixed asphalt concrete strength (dry and wet) is evaluated.

Two mix aging techniques are considered, together with an asphalt aging technique. Two different gradations are taken into account, as well as two asphalt binder contents (optimum according to Marshall mix design method and lowest allowable according to current Costa Rican plant tolerance on asphalt content), and three additive conditions (lime, plastomer, and none).

The objectives of this research project are: • Determine the most critical aging conditions, in regard to retained strength (nominal and percentage). • Identify the most significant variables associated to retained strength, considering the following experimental

factors: additive, gradation, asphalt binder content and aging technique.

Costa Rican aggregates and asphalt binders are used in order to gather valuable information regarding actual paving materials and to aid in the development of new specifications.


7,038 words including the Abstract

Evaluating the Performance of Modified Asphalt Binders with Identical High-Temperatures PG’s but Varied Polymer Chemistries

by

Kevin D. Stuart and Jack S. Youtcheff Federal Highway Administration

Turner-Fairbank Highway Research Center 6300 Georgetown Pike

McLean, VA 22101-2296 TELEPHONE: (202) 493-3073

FAX: (202) 493-3161

and

Walaa S. Mogawer, Ph.D, P.E. Civil and Environmental Engineering Department

University of Massachusetts Dartmouth North Dartmouth, MA 02747

TELEPHONE: (508) 999-8468 FAX: (508) 999-8964


Stuart, Mogawer, and Youtcheff 2

Abstract The objective of this study was to determine if the Superpave high-temperature properties of polymer-

modified asphalt binders correlate to asphalt mixture rutting resistance. The rutting resistances of

mixtures containing polymer-modified asphalt binders with identical performance grades, but varied

polymer chemistries were evaluated. Eleven asphalt binders were obtained for this study: two

unmodified asphalt binders, an air-blown asphalt binder, and eight polymer-modified asphalt binders.

Five binders used in a prior study were also included.

Asphalt binder properties were measured by a dynamic shear rheometer. Mixture rutting resistance

was measured by: (1) G* and G*/sinδ, (2) cumulative permanent shear strain (CPSS), (3) the rut depths

from the French Pavement Rutting Tester (French PRT), and (4) the creep slopes from the Hamburg

Wheel-Tracking Device. CPSS and the rut depths from the French PRT were the primary mixture tests

because they were specifically developed to measure rutting resistance under dry conditions.

The high-temperature properties of the 11 asphalt binders had a high correlation to mixture rutting

resistance as measured by the CPSS’s. A weak correlation was found using the French PRT. Both

correlations were high when analyzing the data from all 16 asphalt binders and mixtures. The number of

discrepancies between the high-temperature properties of the asphalt binders and mixture rutting

resistance was low. A change in high-temperature PG from 70 to 76 significantly increased rutting

resistance based on both mixture tests.


A New Criterion For Superpave High Temperature Binder Specification

By

Raj Dongré, Ph. D. Consultant, Federal Highway Administration 6300 Georgetown Pike, McLean, VA-22101 (703) 395-8854 [email protected] John D’Angelo, P. E. Federal Highway Administration 400 Seventh Street, NW Washington, D.C. 20590 (202) 366-0121 John.D’[email protected] and Gerry Reinke MTE Services Inc. 915 Commercial Ct. Onalaska, WI – 54650 (608)-781-4683 [email protected] Word Count:

Text = 3106

6 Tables = 1500

9 Figures = 2250

Total = 6856

Submitted August 2003 to The Transportation Research Board For Presentation and Publication at the 83rd Annual Meeting of TRB.

August 1, 2003


Abstract

This paper describes the results of a study conducted to determine a new binder parameter that may replace the existing Superpave high temperature specification parameter (G*/sinδ). The current parameter (G*/sinδ) is inadequate due to increasing concerns of its applicability to polymer and other modified asphalt binders (PMA). In this study several parameters were calculated from rheological test data generated on four asphalt binders of different grades at four test temperatures. Two of the binders were unmodified and the other two were modified binders. Laboratory hot-mix rutting tests were also conducted at three temperatures on the Asphalt Pavement Analyzer (APA) and the Dry Hamburg rut testers. It was found that the APA overestimated the rutting potential of modified binders used in this study. The Dry Hamburg produced reasonable results. From the correlation between Dry Hamburg data and binder parameters, the storage viscosity, η’, was was found to be the most promising binder parameter that can adequately characterize the rutting resistance of both unmodified and modified asphalt binders. This is because out of all the other parameters it is the easiest to measure with minimal change in existing instrumentation and software. A specification criterion for η’ was also determined. According to the new criterion the temperature at which the η’ has a value of 220 Pa.s for RTFOT aged asphalt binders is the high PG grade temperature that may reasonably replace the current Superpave high PG grade temperature obtained using G*/sinδ.


Modeling Permanent Deformation Using Laboratory, Proto-type, and In-Service Accelerated Pavement Testing.

By

Sivaranjan Sivasubramaniam, Research Assistant1 [email protected]

Khaled A Galal, Ph.D.2

Pavement and Materials Research Engineer [email protected] (corresponding author)

A.Samy Noureldin, Ph.D., P.E.2

Transportation Research Section Manger [email protected]

Thomas D. White, Ph.D., P.E.

Professor and Head, School of Civil Engineering Mississippi State University [email protected]

Mississippi State, MS 39762 Tel (662)325-7185

John E. Haddock, Ph.D., P.E.1

Assistant Professor of Civil Engineering [email protected]

1 School of Civil Engineering

Purdue University West Lafayette, IN 47906

Tel (765) 463-1521 Fax (765) 497-1665

2 INDOT – Research Division West Lafayette, IN 47906

Tel (765) 463-1521 Fax (765) 497-1665

This Paper is Submitted for Consideration of Presentation at the annual TRB meeting in

January 2004 and the Publication of the TRB Journal. (August 1, 2003)

Word Count: 7500 word, including tables and figures

TRB 2004


2

Abstract State Departments of Transportation began using the Superpave mixture design system and the associated material specifications, without long-term validation. This design system is based on the Strategic Highway Research Program performance models which need further calibration. Within this context, the National Center for Asphalt Technology built and tested several test sections on a full-scale oval test track in Opelika, Alabama. One purpose of the track was to provide validation of the Superpave mixture design method. The test track also provided a unique opportunity to verify the relationships between the PURWheel laboratory wheel tracker, the Indiana Department of Transportation/Purdue University Accelerated Pavement Tester and the in-service track performance.

The verification was accomplished by replicating eight hot-mix asphalt mixtures from the test track in the Accelerated Pavement Tester (APT). Samples were also taken from the APT facility and the test track and tested in the PURWheel. A simple power model was used to relate the rutting performance in both the Accelerate Pavement Tester and the PURWheel. The results demonstrate a strong correlation between the two, and their capabilities to predict the in-service rutting performance at the test track. The effect of initial density and varying in-service temperatures on rutting performance is also presented and explained.


Accelerated Moisture Susceptibility Testing of Hot Mix Asphalt (HMA) Mixes

M. Shane Buchanan, Ph. D., P.E. Assistant Professor

Civil Engineering, Mississippi State University 235 Walker Engineering Building, Mississippi State, Mississippi 39762

Phone: (662) 325-3838, Fax: (662) 325-7189 e-mail:[email protected]

Vernon Moore

Graduate Research Assistant, Mississippi State University

235 Walker Engineering Building, Mississippi State, Mississippi 39762 Telephone: (662) 325-3050, Fax: (662) 325-7189

e-mail:vmoore@engr. msstate.edu

Rajib B. Mallick. Ph.D. PE, Corresponding Author Assistant Professor

Civil and Environmental Engineering Department, Worcester Polytechnic Institute Worcester, MA 01609,

Phone: 508 831 5289, Fax: 508 831 5808 e-mail: [email protected]

Sean O’Brien

Graduate Student, Civil and Environmental Engineering Department

Worcester Polytechnic Institute, Worcester, MA 01609 Phone: 508 831 6034, Fax: 508 831 5808


Ali Regimand President

InstroTek, Inc. 3201 Wellington Court, Suite 101, Raleigh, NC 27615

Phone: 919 875 8371, Fax: 919 875 8328, E-mail: [email protected]

Paper prepared for presentation and publication at the 83rd Transportation Research

Board Annual Meeting, Washington, DC, January 11-15, 2004


Buchanan, Moore, Mallick, O’Brien and Regimand

1

ACCELERATED MOISTURE SUSCEPTIBILITY TESTING OF HOT MIX ASPHALT (HMA) MIXES

by

M. Shane Buchanan Vernon Moore

Rajib B. Mallick Sean O’Brien Ali Regimand

ABSTRACT

A rational test protocol is needed to better condition and evaluate hot mix asphalt (HMA) mix stripping potential. A prototype Moisture Induced Stress Tester (MIST) is currently undergoing preliminary laboratory evaluation. The basic set up for the MIST consists of a system using a supply of compressed air to load and apply vacuum to force water out and in (respectively) through a HMA sample, which is kept in water maintained at a constant temperature. The objective of this paper is to present the results of a study being conducted on development, evaluation, and refinement of the MIST. The scope of work reported in this paper consists of work conducted for evaluation of the MIST procedure, and determining the optimum test pressure, test cycles, and temperature for the MIST testing. Testing was conducted on gravel, limestone and granite mixes at 60oC and for different time intervals, and data on turbidity of water used for conditioning in the MIST was collected and analyzed. MIST testing conducted with 30-35 mm thick HMA samples using 60oC and 5,000 to 9,999 cycles seems to provide effective conditioning. The conclusions from this study are that MIST is capable of detecting adhesion failure (stripping), and that the MIST determined turbidity ratio difference shows promise as a tool of predicting moisture susceptibility. Once stripping (adhesion) problems are identified using the MIST device, effective porosity change in the sample could possibly indicate cohesive failures, eliminating the need for a highly variable tensile strength ratio (for retained strength) tests.


James A. Scherocman et. Al. 1

Innovation of Compaction Techniques for HMA

James A. Scherocman, P.E. Consulting Engineer, 11205 Brookbridge Drive Cincinnati, OH 45249, USA Phone: 513-489-3338, Fax:513-489-3349, [email protected] Dr. Yukinori Nose, Sakai America, Inc. 90 International Pkwy, Adairsville, GA 30107, USA Phone: 770-877-9433, Fax:770-877-9886, [email protected] Todd Mansell Graniterock, 411 Walker St., Watsonville, CA 95077 Phone: 831-768-2000, Fax: 408-487-3134, [email protected] TOTAL NUMBER OF WORDS: 7500 including abstract, text, and reference.




James A. Scherocman et. Al. 2

ABSTRACT The advent of the new Superpave designed asphalt concrete pavement mixes has created some problems with achieving the required level of density in these mixtures when placed on the roadway. In some cases, the Superpave mixes are very stiff and difficult to compact due to the large amount of crushed fine aggregate incorporated into the mix. In other cases, particularly for coarse graded Superpave mixtures--those designed with aggregate gradations below the maximum density line--the mixtures are tender and move or shove under the applied compactive effort. In order to improve the efficiency of the compaction process for both stiff and tender Superpave mixtures, a high frequency double drum vibratory roller was developed by Sakai Heavy Industry, Ltd., to obtain the required level of density before the mix cools to a level where density can not be achieved. Use of a high vibratory frequency permits the roller to be operated at a higher speed needed to obtain density and still obtain the required impact spacing to achieve smoothness in the asphalt concrete layer. In addition, a vibratory rubber tire roller was also developed by the same company. This new compaction concept was tested in Japan with the aim of imparting a more uniform level of compaction throughout the asphalt pavement layer thickness. It was found that the combination of the kneading action and the vibratory force of the rubber tires would increase the uniformity of the density obtained at both the top and the bottom of the asphalt pavement layer.


Tandon et al. Page 1 of 24

Results of Simple Performance Tests and Environmental Conditioning System Integration Efforts

Vivek Tandon, Babu S. Kambham, Ramon Bonaquist, and Mansour Solaimanian

By Vivek Tandon Assistant Professor Center for Transportation Infrastructure Systems The University of Texas at El Paso El Paso, Texas 79968-0516 Ph: 915-747-6924 Fax: 915-747-8037 Email: [email protected] Babu S. Kambham Graduate Research Assistant Center for Transportation Infrastructure Systems The University of Texas at El Paso El Paso, Texas 79968-0516 Ph: 915-747-5464 Fax: 915-747-8037 Email: [email protected] Ramon Bonaquist Chief Operating Officer Advanced Asphalt Technologies 6300 Georgetown Pike McLean, VA 22101 Ph: 703-444-4200 Fax: 703-444-4368 Email: [email protected] Mansour Solaimanian Senior Research Associate Pennsylvania State University 219 Transportation Research Building University Park, PA 16801 Ph: 814-863-1903 Fax: 814-865-3039 Email: [email protected]


Tandon et al. Page 2 of 24

ABSTRACT Under the guidance of SHRP, an Environmental Conditioning System was developed that simulated field conditions to identify moisture sensitivity of asphalt concrete mixes. However, the system was not included in the Superpave due to poor repeatability. Studies conducted at the University of Texas at El Paso improved prediction capabilities of the conditioning system. The modified system uses resilient modulus as a moisture sensitivity indicator.

Resilient modulus has been commonly used by highway practitioners as an indicator of hot mix asphalt concrete performance. However, as an extension to the Superpave system, under NCHRP project 9-19, researchers have proposed Simple Performance Tests to evaluate performance of asphalt concrete. These simple performance tests are referred to as dynamic modulus, flow number and flow time. It has been the objective of this study to evaluate the potential of theses tests, when integrated with ECS, to predict moisture damage in lieu of the resilient modulus.

To achieve this objective three mixes of known performance were selected and conditioned using conditioning procedure of modified system. The Simple Performance Tests were performed on unconditioned as well as ECS conditioned specimens.

The integration results indicate that the flow number and flow time tests, as conducted during this study, do not have potential to replace resilient modulus in ECS for identification of moisture susceptible asphalt concrete in the present form. However, the dynamic modulus test demonstrated the potential as a performance indicator replacing the resilient modulus test. In this paper, results of the integration efforts are presented. KEYWORDS: ECS, SPT, Moisture Damage, Dynamic Modulus, Flow Number, Flow Time Word Count Abstract 247 Text 4,492 Figure (3X 250) 750 Table (7X 250) 1,750 Total 7,239


Andrei, Witczak, Schwartz, and Uzan (2004) 1

Harmonized Resilient Modulus Test Method for Unbound Pavement Materials

Dragos Andrei (Corresponding Author) Fugro-BRE, Inc. 8613 Cross Park Drive Austin, Texas 78754 512.977.1834 (voice) 512.976.9565 (fax) [email protected] Matthew W. Witczak Department of Civil and Environmental Engineering Arizona State University Tempe, Arizona 85287-5306 480.965.2759 (voice) 480.965.0557 (fax) [email protected] Charles W. Schwartz Department of Civil and Environmental Engineering University of Maryland College Park, MD 20742 301.405.1962 (voice) 301.405.2585 (fax) [email protected] Jacob Uzan Transportation Research Institute Technion – Israel Institute of Technology Technion City, Haifa 32000, Israel 972.4.829.3325 (voice) 972.4.822.5716 (fax) [email protected] Body Text Word Count: 4828 Total Number of Figures: 9 Total Number of Tables: 3 Total Equivalent Word Count: 7828 ABSTRACT: The paper describes a new laboratory test protocol for the measurement of resilient modulus of unbound pavement materials. This harmonized protocol combines the best features from four state-of-the art resilient modulus test procedures in current use. The harmonized procedure most closely follows the recommended protocol proposed in NCHRP Project 1-28 Appendix E with some exceptions. The main modifications deal with revised and more rational stress sequences and a more accurate stress-dependent resilient modulus predictive equation. Thirteen different predictive models and 25 sets of resilient modulus test data were evaluated as the basis for the recommended predictive equation.

INTRODUCTION

The determination of the elastic moduli of pavement materials is of vital importance for any mechanistically based design and/or analysis procedure for flexible pavements. The resilient modulus (MR), defined as the unloading modulus after many cycles of repeated loading, is commonly used in


Andrei, Witczak, Schwartz, and Uzan (2004) 2

pavement engineering as an appropriate measure of stiffness for the unbound (i.e., soil) layers in a pavement structure. The characterization of unbound material stiffness using the resilient modulus was incorporated in the American Association of State Highway and Transportation Officials (AASHTO) Pavement Design Guide beginning with the 1986 Edition (1).

The selection of an appropriate design MR value for base, subbase and/or subgrade materials has long been complicated by various test and analysis problems. The National Cooperative Highway Research Program (NCHRP) initiated NCHRP Project 1-28 “Laboratory Determination of Resilient Modulus for Flexible Pavement Design” to address these testing and analysis issues (2). The NCHRP 1-28 study produced an excellent set of recommendations regarding MR characterization using triaxial testing for unbound base/subbase/subgrade soils. However, the NCHRP Project 1-28 recommendation for yet another MR test protocol complicated the standardization of a universally accepted testing procedure that could be implemented throughout the pavement community. As a consequence, NCHRP Project 1-28A “Harmonized Test Methods for Laboratory Determination of Resilient Modulus for Flexible Pavement Design” was initiated to combine the best features of the various resilient modulus testing procedures in current usage (3).

OBJECTIVES

The major objective of NCHRP Project 1-28A (Task II – Unbound Materials) was to develop a single test method for measurement of the resilient modulus of unbound granular base/subbase materials and subgrade soils that harmonized all existing testing protocols: AASHTO T 292-91 (4), AASHTO T 294-92 (5), AASHTO T P46-94 (6) and NCHRP 1-28 Draft-96 (2). The harmonized protocol developed in this research closely follows the recommendations of the NCHRP Project 1-28 Final Report - Appendix E. A flow chart for the original NCHRP Project 1-28 test protocol is provided in Figure 1. The corresponding flow chart for the harmonized protocol developed in NCHRP Project 1-28A is provided in Figure 2. The key differences between these two protocols include:

• Changes in material type definitions • Changes in specimen sizes • Changes in specimen compaction methods • Increased loading time for subgrade soils • Revised stress sequences • Revised predictive equation

TEST PROTOCOL DIFFERENCES

The key differences between the original NCHRP 1-28 and harmonized NCHRP 1-28A test protocols are described in more detail in the following sections.

Types of Materials, Specimen Size and Compaction Methods

The material type designation governs the methods for preparing and compacting the test specimens. The harmonized NCHRP Project 1-28A protocol uses gradation data and Atterberg limits to classify materials as either granular, low plasticity materials (Type 1) and cohesive, plastic materials (PI>10) having a large percent of fines (Type 2). These two types of materials require different compaction techniques in order to simulate the structure of the in situ compacted material.

Once the material is classified, the next issue addressed in the protocol is the size of the test sample. The original NCHRP Project 1-28 protocol (Figure 1) recommended the use of 71 mm (2.8 in), 102 mm (4 in) and 152 mm (6 in) diameter samples, depending on the maximum particle size (dmax) of the material. Also, for both types of materials (Type 1 and Type 2), a method for scalping and replacing the coarsest material is specified for certain conditions, as illustrated in the flow chart in Figure 1. The method of scalping and replacing the coarsest material is directly related to the dimensions of the specimen and has the purpose of maintaining an acceptable dmax/D ratio, where D is the diameter of the sample (mold). In the case of a Type 2 material, the original NCHRP 1-28 protocol permits use of the 71 mm (2.8 in) mold for materials with less than 10% retained on the 12.5 mm (0.5 in) sieve.


Paper No. 04-4490

TITLE:

COMPARISON OF FIELD AND LABORATORY PERMEABILITY OF HMA MIXTURES

AUTHORS: Kunnawee Kanitpong1

Robert Schmitt2

Hussain Bahia1 Jeffery Russell1

1Department of Civil and Environmental Engineering The University of Wisconsin – Madison 2210 Engineering Hall, 1415 Engineering Dr. Madison, WI 53706, (608) 265-4481 [email protected], [email protected], [email protected] 2Department of Civil and Environmental Engineering The University of Wisconsin – Platteville

1 University Plaza Platteville, WI 53818, (608) 342-1566 [email protected]


Transportation Research Board 83rd Annual Meeting January 11-15, 2004

Washington, D.C.


Kanitpong, Schmitt, Bahia, and Russell 1

Comparison of Field and Laboratory Permeability of HMA Mixtures By Kunnawee Kanitpong, Robert Schmitt, Hussain Bahia, and Jeffery Russell Abstract: Field permeability testing of asphalt mixtures is very important since it can measure an actual rate of water infiltration into the pavement structure based on the finished pavement layer. It is however necessary to estimate the permeability before construction during the mixture design process. The laboratory permeability testing is, therefore, necessary. This study was conducted based on four fine-graded mixes projects to compare field permeability testing result using the NCAT field permeameter device and the laboratory permeability testing results for field cores and laboratory compacted specimens by using a Flexible wall permeameter following the ASTM D5084 method. In addition, the study included evaluating the relationships between the density, thickness, and permeability in the lab and in the field. The results indicate that the field permeability correlates well to the lab permeability measured on the field cores taken from the field. There is, however, a significant difference between the two measurements as the field measurements are on the average an order of magnitude higher than the lab permeability. The relationship between field and lab measurements of SGC specimens is not as good. There is only a fair relationship between the lab permeability of field cores and lab compacted specimen. Therefore, it appears that the lab permeability testing of the field cores can be used as a good predictor of field permeability but this is not true for the lab compacted specimens. The lab compacted specimen does not offer a good representation of field permeability and thus cannot be used for designing and predicting the permeability of the field layers. The density shows some effect on permeability, however, the thickness do not show any significant effect. Key words: field, laboratory, permeability, permeameter, asphalt, density, thickness


1

Rheological Properties of Asphalt Mixtures Containing Recycled Asphalt Pavement (RAP)

Jo Sias Daniel Assistant Professor Department of Civil Engineering University of New Hampshire 235 Kingsbury Hall Durham, NH 03824 Ph: (603) 862-3277 Fax: (603) 862-2364 Email: [email protected] Aaron Lachance Graduate Research Assistant Department of Civil Engineering University of New Hampshire A115A Kingsbury Hall Durham, NH 03824 Ph: (603) 862-1433 Fax: (603) 862-2364 Email: [email protected] Submitted for Presentation at the 2004 TRB Annual Meeting and Publication in the Transportation Research Record: Journal of the Transportation Research Board Word Count: 6431 words (3931 text, 10 tables and figures) July 2003


2

ABSTRACT

Recycled Asphalt Pavement (RAP) is created from the reclamation of damaged pavements during the preparation for placement of new mixtures. Historically, RAP was disposed of in landfills and considered to be a worthless byproduct of roadway rehabilitation. However, as the space available in landfills and the amount of high quality virgin aggregate declines, the use of RAP in new asphalt concrete mixtures has become common. This research examines how the addition of RAP changes the mechanistic properties of asphalt mixtures. A Superpave 19 mm mixture containing 0% RAP is used as the control for evaluating properties of mixes containing 15%, 25%, and 40% RAP. Testing includes complex modulus and creep compliance tests. Using the time-temperature superposition principle, dynamic modulus and creep compliance master curves are constructed to describe the behavior of each mix over a range of temperatures.

INTRODUCTION

The use of recycled asphalt pavement (RAP) material is increasing as local, state and federal transportation agencies make more efficient use of their resources. RAP material is generated when old, damaged pavement materials are milled and crushed for addition as a component to new mixtures placed in the pavement structure. Historically, old pavement material was removed and disposed of in landfills. As landfilling these materials has become less practical and more expensive and the availability of quality virgin materials declines, the addition of RAP to pavement mixtures has become more and more prevalent. Recycling of pavement material can be done as an in-place process or a central plant process. The in-place process combines the reclamation, mixing, laydown, and compaction procedures into a single paving train in the field. In-place recycled materials are typically used for base or binder courses and are typically overlaid with a surface course. The central plant process involves stockpiling RAP at the asphalt plant, which is then mixed with virgin materials at the plant and trucked to the construction site for laydown and compaction. The state of New Hampshire currently allows up to 35-50% RAP material to be used in base or binder courses and up to 15% RAP in surface courses.

The addition of RAP to an asphalt mixture changes the mechanistic properties (i.e., strength, durability) of the mixture and affects its performance (i.e., resistance to cracking and deformation) in the field. The mechanistic properties change as a result of the aged binder introduced to the mixture as part of the RAP. The binder in the RAP will have a different chemical composition and different properties than the virgin binder added during the mixing process. These two binders will mix to some extent, changing the properties of the mixture containing RAP from one that contains only virgin material. The properties of the aggregate in the RAP will also affect the final mixture properties, particularly if the aggregate is different from the virgin aggregate used in the mixture. As the pavement industry moves towards more mechanistic based pavement design and analysis methods such as the American Association of State Highway and Transportation Officials (AASHTO) 2002 Design Guide and proposed Simple Performance Test (1), it is essential to evaluate the effect of RAP on the properties of asphalt mixtures.

There is much interest in the use of RAP at both the local and national levels and any data obtained will benefit the understanding of the use of RAP. Current research in the area deals with binder properties (2), mixture design and specification development, but not specifically with the change in mechanistic material properties with the addition of RAP. The use of RAP was listed as one of the research priorities among member state Departments of Transportation at the 2001


Upgraded TTI Overlay Tester: A Simple Reflective Cracking Simulation Test

Fujie Zhou

Assistant Research Scientist, Texas Transportation Institute

501F CE/TTI Building, Texas A&M University, College Station, TX 77843

Phone: 979-458-3965, Fax: 979-845-1701, Email: [email protected]

Tom Scullion

Research Engineer, Texas Transportation Institute

501E CE/TTI Building, Texas A&M University, College Station, TX 77843


Richard Williammee, P. E.

Texas Department of Transportation

Fort Worth, TX 76115-0868


Paper Submitted to the Transportation Research Board for Presentation and Publication at the 2004 Annual Meeting in Washington, D. C.

Words: 4334 Figures: 8 Total: 6334


ABSTRACT: Reflective cracking is the major distress of asphalt overlay on existing pavements. Normally, the opening and closing of joint and/or crack induced by daily temperature change is the main “contributor” to the reflective cracking. This mechanism is further validated in this paper by the field observation on US175 and US84 Remixer sections plus state highway 6, Texas. Furthermore, Texas Transportation Institute (TTI) overlay tester designed to simulate this mechanism is described in this paper. Especially, an upgraded overlay tester has been developed for testing the small sample with 150 mm long by 76 mm wide by 38 through 50 mm high, which can be easily made from Superpave gyratory compactor and/or field cores. This improvement makes the overlay tester easier and more practical for routine use. In addition, the repeatability of overlay tester has been studied. The results indicates that overlay tester is very repeatable, and the average reflective cracking life of two samples will be within ± 12 percent of the “true” reflective cracking life of asphalt mixture with 95 percent reliability. Finally, three case studies have been used to validate the upgraded TTI overlay tester. The results clearly show that upgraded TTI overlay tester can effectively differentiate the reflective cracking resistance of different asphalt mixtures. It is also found that the reflective cracking resistance of asphalt mixture has a good correlation with the asphalt binder used. Stiff binder has poorer reflective cracking resistance than soft binder. KEY WORDS: Reflective Cracking, Overlay Tester, Asphalt Overlay


Bouldin and Dongre

Page 1 of 25

NOVEL HIGH PERFORMANCE COMPOSITES FOR HOT MIX

ASPHALT APPLICATIONS

By

Mark G. Bouldin, Ph.D

Pebblecrest Materials & Service Corp.

24165 IH-10 West, Suite 217-268

San Antonio, TX 78257

Tel: (830) 755-4226

Fax: (530) 937-9517


and

Raj Dongré, Ph.D

Federal Highway Administration/Salut

6300 Georgetown Pike, McLean-VA-22101

Tel: (202) 493-3104

Fax: (703) 783-0305


Word Count:

Text = 3000

9 Tables = 2250

8 Figures = 2000

Total = 7500

Submitted August 2003 to The Transportation Research Board For Presentation and Publication at the 83rd Annual Meeting of TRB.

August 1, 2003


Bouldin and Dongre

Page 2 of 25

ABSTRACT

Hot mix asphalt (HMA) aggregates were pre-treated with Gilsonite and Gilsonite-modified elastomers. These blends were compared with the non-treated mix as well as a mix where the pre-treatment additive had been blended into the binder rather than with the aggregate/filler. These mixes were subsequently evaluated with respect to their rut resistance and moisture susceptibility. The initial results indicate that advanced composite systems may be created which provide significant performance benefits. The experimental results support the idea that ultra-high viscosity Gilsonite-based modifier creates an interlayer between the aggregate surface and the binder matrix. This significantly enhances the overall mix performance without negatively affecting the binder’s low temperature properties.

Keywords: advanced composite, Gilsonite-based interlayer, rutting, stripping, mix modifier


Suriyanarayanan Sadasivam, N.Paul Khosla and Glen.A.Malpass 1

NCSU Wheel Tracking Device: Its Ability to Predict Rutting of Superpave Mixtures Suriyanarayanan Sadasivam, Graduate Research Assistant, North Carolina State University, Raleigh, NC, 27695-7908 ssadasi@ ncsu.edu Phone: (919) 515-4233 Fax: (919) 515-7908 N.Paul Khosla * Professor of Civil Engineering, North Carolina State University, Raleigh, NC, 27695-7908 [email protected] Phone: (919) 515-7835 Fax: (919) 515-7908 Glen A. Maplass, Graduate Research Assistant, North Carolina State University, Raleigh, NC, 27695-7908 [email protected] Phone: (919) 515-7744 Fax: (919) 515-7908 * Corresponding Author Word Count: 6552 words


Suriyanarayanan Sadasivam, N.Paul Khosla and Glen.A.Malpass 2

ABSTRACT There are several accelerated loaded wheel testers in practice to evaluate the rutting potential of the asphalt concrete mixtures. The NCSU Wheel Tracking Device (WTD) was designed to simulate the field conditions of asphalt concrete pavements from construction to application. The NCSU WTD is used to rutting performance of the mixtures. The slabs for rutting tests were compacted using the WTD instead of a conventional roller. The device has a compaction foot that can be used to compact slabs of 540mm x 430mm in 75mm lifts at a desired air void content. The compaction and the rutting tests are controlled by windows based software. The mixtures for the test specimens were obtained from the test sites. The field mixtures were selected in such a way that each mixture had a different type of aggregate gradation and nominal size of aggregate. The rut tests were performed using a rubber tire of 100 psi for 10000 cycles of loading at 60oC. The rutting profile of the slab was measured after every 1000 cycles of loading using a laser measurement system. The cylindrical specimens were cored out from the rolling wheel compacted slabs. The Repeated Shear test at Constant Height (RSCH) was performed on these specimens. The rut depths were estimated using the SHRP rutting model. The results of the WTD rut tests were compared with the rut depths estimated from the shear strains of the RSCH test. The comparison showed significant correspondence between the WTD rut test and RSCH test.


EVALUATION OF MODIFIED GERMAN ROTATING FLASK

By

Satish Ramaiah,

Turner Fairbanks Highway Research Center, Federal Highway Administration

6300 Georgetown Pike, McLean, VA – 22101

Phone 202-493-3103

Fax 202-493-3161

Raj Dongre, Ph.D.

Turner Fairbanks Highway Research Center, Federal Highway Administration

6300 Georgetown Pike, McLean, VA – 22101

Phone 202-493-3104

Fax 202-493-3161

And

John D’Angelo, P. E.

Office of Pavement Technology, Federal Highway Administration

400 S. 7th Street, Washington, D. C.

Phone 202-366-0121

Fax 202-493-2070

Text - 3320 words 9 Tables 6 Figures


Ramaiah, Dongre, & D’Angelo

2

2

ABSTRACT

This report summarizes the findings of a study conducted to evaluate the Modified German

Rotating Flask (MGRF). The purpose of this evaluation was to determine if the MGRF might be

used as replacement for the Rolling Thin Film Oven (RTFO) aging method. The RTFO has been

found to be inadequate in aging polymer modified binders. This study was completed in three

phases using a wide range of asphalt binders, which were primarily polymer modified asphalt

binders. Phase I, was conducted to evaluate the effects of temperature and rotation speed on

aging. In Phase II the goal was to identify off-the-shelf components so that the MGRF may be

assembled easily. A fully functional off-the-shelf MGRF was developed at the completion of

Phase II. The cost of this equipment is approximately $3500. Phase III, was conducted to evaluate

the effects of MGRF aging procedure on a wide range of asphalt binders. In Phase III full range of

binder physical properties were determined to grade all binders according to AASHTO M320 and

MP1-a. It was found that the MGRF aging procedure did not significantly affect the PG grade of

the asphalt binders studied. Therefore from the available data it may be concluded that MGRF

aging is equivalent to RTFO. The advantage of using the MGRF is that it does not have the run out

problems faced by the modified binders in an RTFO oven.




Title: “Aggregate Shape Classification System Using AIMS” Authors: Taleb Al -Rousan1, Eyad Masad2, Leslie Myers 3, Dallas Little4 and John D’Angelo3 1Graduate Research Assistant 2Assistant Professor 4Professor Texas Transportation Institute Texas A&M University 3135 TAMU College Station, TX 77843-3135 E-mail: [email protected], Tel: 979-845-8308, Fax: 979-845-0278 3 Asphalt Pavement Team Office of Pavement Technology Federal Highway Administration


Number of words= (4254 WORDS + 2 Table@250 + 11 Figures@250) = 7504


Al-Rousan et al. 2

ABSTRACT This paper presents a framework for the development of a comprehensive system

for classifying the shape properties of both fine and coarse aggregates. This classification system offers several advantages over current methods used in practice. Coarse aggregate form is analyzed using the three dimensions of particles which allow distinguishing between flat, elongated or flat and elongated particles. Angularity is analyzed based on measurements of surface irregularities. Surface texture is quantified us ing wavelet analysis. The texture influence on hot mix asphalt (HMA) performance has been missing in the past due to the lack of a technique to accurately quantify this important characteristic. These shape properties are measured using the recently developed Aggregate Imaging System (AIMS).

AIMS was used to measure the shape characteristics of 22 coarse and fine aggregate samples with different sizes. Each of the shape characteristics in an aggregate sample was described by a cumulative distribution function rather than an average value. Consequently, statistical analysis was used to compare results obtained from analyzing these aggregates with those obtained from analyzing the shapes used in the past by geologists for visual classification of particles. This comparison has lead to the development of a classification system.

Keywords: Aggregate, Shape, Angularity, Form, Texture, Imaging, AIMS, Classification.


1

VARIABILITY OF AIR VOIDS AND MECHANISTIC PROPERTIES OF PLANT PRODUCED ASPHALT MIXTURES

By

Louay N. Mohammad1, Ph.D. Corresponding Author Zhong Wu2, Ph.D., P.E.

Chenggang Zhang 3 Mohammad J. Khattak4, Ph.D.

Chris Abadie5, P.E.

Louisiana Transportation Research Center 4101 Gourrier Lane

Baton Rouge, LA 70808 Phone: (225) 767-9126

Fax: (225) 767-9108 E-mail: [email protected]

Submitted to:

83th Transportation Research Board Annual Meeting January 11-15, 2004

Washington, D.C.

1 Associate Professor, Depart. of Civil and Environmental Engineering and Louisiana Transportation Research Center, Louisiana State University, 4101 Gourrier Ave, Baton Rouge, LA 70808.

2 Research Associate, Louisiana Transportation Research Center, 4101 Gourrier Ave, Baton Rouge, LA 70808

3 Graduate Research Assistant, Louisiana Transportation Research Center, 4101 Gourrier Ave, Baton Rouge, LA 70808

4 Assistant Professor, Depart. of Civil Engineering University of Louisiana at Lafayette, PO Box 42991, Lafayette LA 70504.

5 Material Research Manager, Louisiana Transportation Research Center, 4101 Gourrier Ave, Baton Rouge, LA 70808


2

ABSTRACT

This paper presents the results of a laboratory and field evaluation of the variability of

physical and mechanistic properties of plant produced asphalt mixtures. Three asphalt

mixtures from two overlay rehabilitation projects were selected. Comparison analyses were

conducted on density measurements between two laboratory (AASHTO T-166 and ASTM

D6752-02, or CoreLok) and one in-situ test (PQI) methods. In addition, two laboratory

mechanistic tests: Indirect tensile (IDT) strength and Frequency sweep at constant height

(FSCH) tests, and two field non-destructive tests using falling weight deflectometer (FWD)

and light weight falling weight deflectometer (LFWD) were performed to characterize the

variability of the plant produced mixtures evaluated in this study. Superpave Gyratory

Compactor (SGC) samples and field cores were used in the laboratory testing program. A

strong correlation was observed between the two laboratory bulk specific gravity test

methods: the AASHTO T-166 and the CoreLok. The IDT strengths of SGC samples were

found higher than those of field cores. A good correlation was found between the complex

shear moduli of SGC samples and field cores. Field test results indicated that LFWD test may

be used as an alternative for the FWD test in pavement structure evaluation.

KEYWORDS: Asphalt, mixture, air void, core, SGC, IDT, FSCH, FWD, LFWD, PQI, CoreLok


Paper No. 04-4734

TITLE:

CAN CHEMICAL MODIFICATION OF PAVING ASPHALTS BE EQUATED TO POLYMER MODIFICATION? A LABORATORY STUDY

AUTHORS: Hossein Ajideh 1

Andres Rangel 2 Hussain Bahia1

1Department of Civil and Environmental Engineering The University of Wisconsin – Madison 2210 Engineering Hall, 1415 Engineering Dr. Madison WI, 53706, (608) 265-4481 [email protected], [email protected]

[email protected] 2 Laboratory Manager

Texpar Energy, Inc.

2020 Springdale Road Waukesha, WI 53186



83 rd Annual Meeting January 11-15, 2004

Washington, D.C.


Ajideh, Rangel, and Bahia

2

ABSTRACT Chemical modification of asphalt binder by an acid has been known for quite some time. Chemically modified asphalts can extend the upper application limit, and prevent possible rutting of an asphalt mixture by improving asphalt stiffness. During the past two decades many studies have been focused on polymer modification indicating polymer additives can successfully improve asphalt pavement performance. The low cost of acid modification, relative to polymer and other modifiers, makes the acid modification alternative very important and competitive. Unlike other modifiers, information about acid chemically modified asphalts is limited and performance data is almost non-existent. During the past few years major advancement in characterization of load-related damage resistance behavior of asphalt binders has been achieved. A new protocol for measuring resistance of binders to rutting and to fatigue damage has been introduced by the NCHRP 9-10 project. In addition new protocols to measure construction relation properties, such as Zero Shear Viscosity for mixing and compaction and storage stability under static and high agitation conditions, are proposed. This study was conducted to evaluate and compare the effectiveness of two types of chemical treatments with acid and one polymer modifier in improving damage and construction related properties of asphalt binders and asphalt mixtures. A PG 64-22 was used as the base asphalts and was modified with various types of chemical and polymer additives. The results indicate that chemically modified asphalts show significant improvement in rutting and fatigue resistance. It is found, however, that unlike polymer modified asphalt; the effect of aging on rheological and engineering properties of chemically modified asphalts is significantly different. There are also indications that moisture damage of mixtures made with chemically modified asphalts are significantly different than those made with polymer modified asphalts.


1

Falling Weight Deflectometer Spatial and Temporal Variability within and between Pavement Sections of

the Virginia Smart Road

Alexander K. Appea (Former Graduate Student at Virginia Tech)

Florida Department of Transportation Materials Research Park

5007 NE 39th Ave Gainesville, FL 32609


Imad L. Al-Qadi Charles E. Via, Jr. Professor of Civil and Environmental Engineering

Roadway Infrastructure Group, Leader Virginia Tech Transportation Institute

200 Patton Hall, Virginia Tech, Blacksburg, VA 24061-0105 Tel: 540 231-5262, Fax: 540 231-7532


Virginia Tech Transportation Institute Virginia Tech

Blacksburg, Virginia


Appea and Al-Qadi 1

FWD Spatial and Temporal Variability within and between Pavement Sections of the Virginia Smart Road

Alexander K. Appea and Imad L. Al-Qadi

ABSTRACT

Falling weight deflectometer measurements were conducted on 12 sections at the Virginia Smart Road to quantify the variability within and between test sections. Measurements were taken on the instrumented and non-instrumented lanes every 10m from May 2000 through October 2002. Pavement temperature data were collected every time FWD testing was conducted. Analysis of the deflection measurements and temperature data resulted in the development of an exponential model for deflections versus temperature for all 12 sections. The model was used to correct deflections within the measured hot-mix asphalt (HMA) temperature range. The temperature correction model was compared to an independently developed correction model. Both models produced the same trend when used for all of the test sections. Seasonal variation of the HMA moduli during freeze-thaw periods, were also observed over a three-year period monitoring from November 1999 to June 2002 for all of the sections. The greatest moduli were backcalculated in January 2001 and December 2001, and the lowest moduli were backcalculated in July 2001 and June 2002. An Analysis of Variance (ANOVA) of the sensor deflections showed significant statistical differences between mean deflections of the different sections. Sensor spacing, with the exception of the last sensor, had no influence on the results. Analysis of deflection results from the first sensor (D0) was successfully used to assess variability among sections at the Virginia Smart Road. The study concluded that temporal and spatial variations exist in the deflections within and between sections at the Virginia Smart Road. The coefficient of variation (COV) ranged from as low as 7% to as high as 42% for the FWD loading plate center deflections. These variations are temperature and pavement-structural dependent.

Keywords: Falling Weight Deflectometer, spatial variation, temporal variation, temperature correction, sensor spacing

INTRODUCTION

Because the estimated structural capacity of existing pavements is known to be affected by the spatial variability of the measured deflections, several studies have focused on the spatial and temporal variability of FWD measurements. Spatial variation is known to be due to the heterogeneous nature of the pavement materials, while temporal variations in material properties are caused by temperature changes. Mamlouk et al. (1) concluded from the results of an extensive study on test sections in Arizona that the variability caused by the equipment was insignificant compared to the spatial variability. Siddharthan et al. (2) analyzed data from six sites, each approximately 300m in length, where the thickness of the HMA layers varied from 75 to 200mm; deflection testing was conducted at 15m intervals. In that study, the authors used Monte Carlo simulation method to statistically investigate the influence of variation in pavement moduli and pavement response strains on pavement analysis and performance. The study showed that the coefficient of variation (COV) of the measured deflections varied from 9% to 48%, with generally higher values occurring at sensors farthest away from the loading plate. It also showed that the variation in pavement strain, caused by variation in FWD measurements, had significant influence on pavement life prediction. Hossain and Zaniewski (3) reported that the variability in FWD deflection data resulted in variability of the pavement’s remaining service life, estimated in terms of equivalent single axle loads (ESAL’s) to cause fatigue failure.

Rauhut and Jordal (4) found FWD deflection COV’s ranging from 4% to more than 40% in 132 flexible and 88 rigid Long Term Pavement Performance (LTPP) sections. The backcalculated stiffness moduli COVs ranged from 13 to 67% for the sections in the United States. Variability in backcalculated moduli for base layers was much higher than for the HMA layers and the subgrade. The researchers also found that COVs for backcalculated HMA moduli were proportional to those for measured deflections at the center of the loading plate. In general, statistical


Ruggedness Evaluation of the Dynamic Angle Validation (DAV) Kit For Superpave Gyratory Compactors

(Word Count: 250-Abstract; 1832-text; 1500-Tables/Figures)

By


University of Arkansas Department of Civil Engineering

4190 Bell Engineering Center Fayetteville, AR 72701

[email protected] (501) 575-8695

(501) 575-7168 Fax

Paper prepared for consideration of presentation and publication by the Transportation Research Board

July 2003


Ruggedness Evaluation of the Dynamic Angle Validation (DAV) Kit For Superpave Gyratory Compactors

Kevin D. Hall

ABSTRACT

Superpave hot-mix asphalt (HMA) specimens are compacted in the laboratory using the Superpave

gyratory compactor (SGC). The SGC compacts specimens through the application of pressure and an

applied angle of gyration. The original compaction specification for the SGC requires the angle of

gyration to be 22±0.35 mrad (1.25±0.02 degrees), measured externally against the compaction mold.

Questions concerning the ability of different compactors to produce HMA specimens of the same mix

having the same density led to the development of the Dynamic Angle Validation (DAV) kit, which

measures the angle of gyration internally (on the inside of the mold). Two tasks groups were formed

independently to develop a standard specification for DAV usage; the groups combined efforts and

produced AASHTO PP-48, with a companion ASTM specification slated for consideration in the Fall of

2003. The specifications do not include a statement of precision and bias. The task group(s) conducted a

ruggedness study using the guidelines contained in ASTM C1067 and E1169. Factors considered in the

ruggedness study included height of mix used in the mold with the DAV; number of gyrations used to

determine the angle of gyration; operating temperature of the DAV; and the nominal maximum aggregate

size of the mix used with the DAV. A total of six SGC models were included in the study. The

ruggedness study showed no factor significantly affected the DAV-measured angle. The findings clear

the way for a planned interlaboratory study to establish the precision of the angle of gyration measured

using the DAV.


Kavanagh 1

A Nine Year Evaluation Of Field Cracking And Rutting Performance Of SPS-9 Superpave Experiment

By Leonnie N. Kavanagh, P. Eng. Surfacing Materials Engineer Materials Engineering Branch 12-215 Garry Street Manitoba Department of Transportation & Government Services Winnipeg, Manitoba R3C 3Z1 Phone (204) 945-1941 Fax (204) 945-2229 Email [email protected]


Kavanagh 2

ABSTRACT Though the first of twenty-six Specific Pavement Studies SPS-9 experiments was built over nine years ago to assess the field performance of the Superpave asphalt and mix design and analysis system, there have been no definitive report on the experiment’s overall field performance. This analysis therefore provides an evaluation of the performance of the SPS-9 experiment using the 2001 distress data available from the Long Term Pavement Performance (LTPP) Information Management System (IMS) database. Field distresses evaluated in this study included rutting, fatigue cracking, longitudinal wheelpath and non-wheelpath cracking, and transverse cracking. In addition to the field distress evaluation, a statistical analysis was conducted to determine whether a performance difference exists between the Superpave “correct” Performance Graded (PG) Binder section and the Superpave Alternate PG Binder section designed to exhibit early distress at each of the SPS-9 sites. The statistical analysis relates the distresses through means (T-test) and variances (F-test). Based on the data analysis, over 78% of the Superpave sections have no cracking, and over 80% have only nominal rutting. When cracking occurred, fatigue and longitudinal non-wheel path cracking were the predominant distresses. For the Superpave Binder sections, distresses began to appear within four years of construction, with overlays outperformed new pavements, and agency sections performing as well or better than Superpave sections. Surprisingly, the result of the T-test and the F-test analysis shows no statistical difference in the fatigue cracking, longitudinal wheelpath cracking, longitudinal non-wheelpath cracking and rutting distresses between the Superpave Binder sections and the Superpave Alternate Binder sections. However, a statistical difference (based on the F-Test) existed for transverse cracking performance between the two PG binder sections.


GAMMA-RAY SPECTROMETRIC METHOD FOR DETERMINING BULK SPECIFIC GRAVITY OF CYLINDRICAL HOT-MIX ASPHALT CONCRETE

SPECIMENS

By

*Linus Dep, Ph.D. Physicist / Research & Development

Troxler Electronic Laboratories 3008 Cornwallis Road

Research Triangle Park, NC 27709 [email protected] (919) 549-8661 Voice (919) 485-2258 Fax

Robert E. Troxler, Ph.D.

Director/ Advanced Technologies Troxler Electronic Laboratories

3008 Cornwallis Road Research Triangle Park, NC 27709

[email protected] (919) 549-8661 Voice (919) 485-2258 Fax

Michael E. Bienvenu, Ph.D., P.E. Manager/ Engineering Research Troxler Electronic Laboratories

3008 Cornwallis Road Research Triangle Park, NC 27709

[email protected] (919) 549-8661 Voice (919) 485-2258 Fax

*Corresponding Author (Paper Length: Text Word Count 3,516 + (Tables/Figures) 15 X 250) = Total 7,216

A Paper Submitted to the 83rd Annual Transportation Research Board for Presentation


Dep, Troxler, and Bienvenu 2

ABSTRACT

This paper examines the precision of a gamma-ray spectrometric method to determine the bulk

specific gravity (Gmb) of cylindrical laboratory prepared and field cored hot-mix asphalt concrete

specimens. The method uses a low-activity spatially distributed Cs-137 gamma-ray source, a

high efficiency energy-selective gamma-ray detector and a spectrum acquisition system. The

instrument design uses axial measurement geometry, as the source and the detector are along the

longitudinal axis of the cylindrical specimen.

This paper presents the principle of the gamma-ray method, and the factors that affect the

Gmb measurement precision. Based on examining specimens made with six different aggregate

types, no measurable effect on Gmb could be found from chemical composition of the specimen.

For thin specimens with heights between 20 to 35 mm, due to the sensitivity of the Gmb

measurement to the specimen height, height should be determined with high precision.

Furthermore, a new method of height measurement of saw-cut specimens with non-parallel flat

faces has demonstrated that the height can be determined to 0.1 mm precision at the 1-sigma

level. Based on an interlaboratory study, for specimens with well-determined heights, the

gamma-ray method of measuring Gmb showed a repeatability of 0.005 and a reproducibility of

0.007 at the 1-sigma level.


AN ANALYSIS OF THREE METHODS OF SAMPLING HOT MIX ASPHALT FROM BEHIND A PAVER

By

R. Christopher Williams, Ph.D. Assistant Professor Department of Civil & Environmental Engineering Michigan Technological University 301B Dillman Hall Houghton, Michigan 49931 phone: 906-487-1630; fax: 906-487-1620 email: [email protected] Andrea N. Kvasnak Research Assistant Department of Civil & Environmental Engineering Michigan Technological University 855 Dow Engineering Building Houghton, Michigan 49931 phone: 906-487-3294; fax: 906-487-2942 email: [email protected] Krista L. Hofmann Research Assistant Department of Civil & Environmental Engineering Michigan Technological University 105 D Dillman Hall Houghton, Michigan 49931 phone: 906-487-2725; fax: 906-487-1620 email: [email protected] prepared for presentation and publication at the 2004 Annual Meeting of TRB Washington, D.C. July 31, 2003 No. of tables =8x250 = 2000 word equivalents No. of figures = 2x250 = 500 word equivalents Text =4834 words TOTAL WORD COUNT= 7335 Words


Williams, Kvasnak, Hofmann 2

ABSTRACT

Quality control/quality assurance specifications are being implemented across the United States as

governmental agencies are move toward statistically based specifications. Amongst several issues that have been raised, is representative sampling for payment. Over the past few years, owner agencies have implemented variations to hot mix asphalt sampling including the use of three-way splitters, Ring and Plate sampling of the hot mix asphalt mat after placement with a laydown machine, and sampling the mat with a shovel. The impacts of the shovel sampling practice on pay factor adjustments are not well known. This paper compares the Ring and Plate sampling procedure and two types of shovel sampling methods. A statistical analysis to determine whether or not statistical differences exist as well as a risk analysis is provided as means to evaluate the three sampling methods. The analysis included categorizing the data by aggregate size, traffic volume, and coarse versus fine mixes.

The statistical and risk analysis indicated that the preferred method of sampling is Plate and Shovel based on the

data collected. The Plate and Shovel sampling in general offers the widest percent within limits acceptance and the least amount of risk concerning the pay deducts. The risk analysis also revealed the adequacy of Monte Carlo Simulation with Latin Hypercube Sampling. Finally, the measured binder contents utilizing the Abson method with trichloroethylene are statistically different than back calculated binder contents using the measured Gmm and the Gse from the job mix formula.


M. J. Crocker, D. Hanson, Z. Li, R. Karjatkar, K. S. Vissamraju 1

Measurement of the Acoustical and Mechanical Properties of Porous Road Surfaces and Tire/Road

Noise

Malcolm J. Crocker, Douglas Hanson*, Zhuang Li, Ravi Karjatkar and Krishna S. Vissamraju

Mechanical Engineering Department *National Center for Asphalt Technology

Auburn University, AL 36849 Tel: 334-844-3310 Fax: 334-844-3306


(total number of words: 7316)


M. J. Crocker, D. Hanson, Z. Li, R. Karjatkar, K. S. Vissamraju 2

ABSTRACT

The absorption coefficient of dense and porous road surfaces has been measured in the laboratory using core samples with 4- and 6-inch diameter impedance tubes and with an impedance tube mounted vertically in situ on the pavement surfaces. The 6-inch tube allows the absorption of a large core sample surface to be determined, but only up to a frequency of about 1250 Hz. The 4-inch tube allows the absorption coefficient to be determined up to a frequency of about 1950 Hz. The two different diameter impedance tubes were also mounted vertically on some of the same pavement types and the absorption coefficient of these pavement types was measured in this way too. The peak sound absorption coefficient measured of the fine and coarse mix aggregate porous surfaces suggests that the first peak frequency and peak absorption coefficient magnitude is only slightly different for the two types of porous surfaces. Since the fine mix aggregate porous surface is smoother, it is preferred since it should result in less tire tread impact noise and thus lower overall tire noise than the coarse aggregate surface. A porous surface of between 1.5 and 2.0 inches thickness is recommended for the type of porous surface examined, if a peak absorption frequency of about 1000 Hz is desired, so as to be most effective at reducing interstate highway noise of automobiles.


Evaluation of Non-Nuclear Density Measurement Devices for Determination of In-place Pavement Density

Graham C. Hurley Research Engineer

National Center for Asphalt Technology 277 Technology Park Auburn, AL 36832

Phone: (334) 844-6228 Fax: (334) 844-6248


Brian D. Prowell Assistant Director

National Center for Asphalt Technology 277 Technology Park Auburn, AL 36832

Phone: (334) 844-6228 Fax: (334) 844-6248


L. Allen Cooley, Jr. Burns Cooley Dennis, Inc.

Formerly, National Center for Asphalt Technology Auburn University, AL


Corresponding Author: Graham C. Hurley Paper No.: 04-4854 Word Count: 4,291 words + 4 Tables (1000 words) + 8 Figures (2000 words) = 7,291 words

Submitted for Presentation and Publication for the 83rd Annual Meeting of the Transportation Research Board.


Hurley et al. i

Evaluation of Non-Nuclear Density Measurement Devices for Determination of In-place Pavement Density

Graham C. Hurley, Brian D. Prowell, and L. Allen Cooley, Jr.

ABSTRACT

The air void content of both in-place and laboratory compacted hot-mix asphalt

(HMA) may be the single factor that most affects the performance of a properly designed mixture. A mediocre mix, well constructed with good in-place air voids, will often perform better than a good mix that has been poorly constructed. Currently, in-place density may be monitored using three methods: cores, nuclear density gauge measurements or non-nuclear density gauge measurements. The objective of this study was to evaluate and compare two non-nuclear density devices, the Pavement Quality Indicator (PQI) Model 301 and the PaveTracker, to in-place core densities. Based upon the testing and analyses of twenty projects, uncorrected gauge measurements (from each gauge) provided reasonable correlation (significant at a 5 percent level of significance) with core density measurements approximately 75 percent of the time. Average coefficients of determination for the relationships between uncorrected gauge measurements and core densities were approximately 0.50. Simulation analyses indicated that the error in measuring in-place air voids using calibrated PQI Model 301 gauge measurements based upon the constant offset method can be 1.0 to 3.97 percent air voids for the average of ten measurements. The numerical experiments also indicated that calibration of the PQI Model 301 by simple offset or by slope and offset did not improve the correlation between the gauge and core densities.


The Role of Bending Beam Rheometer Parameters in Thermal Stress Calculations

Submission date: August 1, 2003 Word count: 3057 plus 2 tables and 9 figures

Submitted to The Transportation Research Board

for Presentation and Publication by

Mihai O. Marasteanu Assistant Professor, University of Minnesota

500 Pillsbury Drive S.E., Minneapolis, MN 55455 Telephone: (612) 625-5558, E-mail: [email protected]


Marasteanu 2

ABSTRACT The development of the Strategic Highway Research Program (SHRP) low temperature

binder specifications were based on the observation that asphalt mixture creep stiffness at 2 hours correlated well with instances of transverse cracking. Extending the correlation to asphalt binder stiffness and using time-temperature superposition, a maximum stiffness value was imposed on the binders and a limiting temperature at which the stiffness at 60 seconds reached the limiting value was selected as a specification criterion. In addition, the slope at 60 seconds of the stiffness vs. time curve on a double logarithmic scale, the so-called “m-value” was introduced as an additional criterion. This paper investigates the role played by the stiffness and the m-value in the development of thermal stresses in asphalt pavements. The analysis shows that thermal stress magnitude is strongly related to the stiffness magnitude. At similar stiffness levels higher m-values result in the faster development of thermal stresses. INTRODUCTION The development of the Strategic Highway Research Program (SHRP) asphalt binder criterion for low temperature cracking was based on the assumption that the 2-hour mixture stiffness correlated well with the severity of thermal cracking in the field (1). This assumption was extended to asphalt binder stiffness obtained in low-temperature creep tests. To expedite the testing process the time-temperature superposition principle was used to show that, for asphalt binders in general, the stiffness at 60 seconds at T1ºC is approximately equal to the stiffness at 2 hours at T1-10ºC (1). The time-temperature superposition was considered valid but actual 2-hour tests were not conducted to experimentally verify it. To keep the PG binder specification to a reasonable level of simplicity the effects of physical hardening were not considered although one of the major findings during SHRP was the significant effect of physical hardening on binder physical properties.

The slope at 60 seconds of the stiffness vs. time curve on a double logarithmic scale, the m-value, was introduced as an additional parameter to control the rheological type of asphalt binders and to eliminate heavily blown asphalts. This additional criterion was based on the idea that a low m-value corresponded to slower relaxation of the thermal stresses that build up at low temperatures, which was detrimental for performance. The most recent addition to asphalt binder low temperature specification is AASHTO MP1a standard (2) which uses a thermo-viscoelastic model to calculate thermal stresses using asphalt binder creep compliance. The stress curve is compared with binder strength data obtained from the direct tension test to arrive at a critical temperature (TCR) below which transverse cracking occurs in the pavement.

OBJECTIVES The objectives of this paper are to investigate the relation between the stiffness and the m-value calculated from the BBR experimental data and the development of thermal stresses in asphalt pavements. The current specification procedure of selecting the highest of the two limiting temperatures given by S(60s) and m(60s) is also investigated. RESEARCH APPROACH The following approach was taken in this research study:


Y. Kim, Hosin “David” Lee, R. Ceccovilli 1

Laboratory Evaluation of Engineered CIR Emulsion and Foamed Asphalt Mixtures for Cold-In-Place Recycling of Asphalt Pavements Y. Kim, Hosin “David” Lee, R. Ceccovilli YongJoo Kim Graduate Research Assistant Public Policy Center Department of Civil and Environmental Engineering 4105 Seamans Center University of Iowa Iowa City, IA, 52242-1527 Tel: 319-335-2957 Fax: 319-335-5660 E-mail: [email protected] Hosin “David” Lee Associate Professor Public Policy Center Department of Civil and Environmental Engineering 4117 Seamans Center University of Iowa Iowa City, IA, 52242-1527 Tel: 319-384-0831 Fax: 319-335-5660 E-mail: [email protected] Renato Ceccovilli Product Development Engineer Koch Materials Company 4027 E. 37th St. North Wichita, KS 67220 Phone: 316-828-8237 Fax: 316-828-7385 E-mail: [email protected] Submission data: Sep 15, 2003 Word count: 4,268 with 4 tables and 12 figures


Y. Kim, Hosin “David” Lee, R. Ceccovilli 2

ABSTRACT The main objective of this research is to compare the laboratory responses of engineered CIR emulsion and foamed asphalt as a binder for RAP materials collected from the cold in-place recycling project on US-20 in Iowa. Based on the visual observation of laboratory specimens, as expected, the engineered CIR emulsion coated the RAP materials better than the foamed asphalt. Foamed asphalt instead created a mastic mixture structure to provide better bonding of RAP materials. Given the same compaction effort, foamed asphalt mixtures obtained higher density than the engineered CIR emulsion mixtures. After four hours of curing in the room temperature, the engineered CIR emulsion mixtures showed less raveling than the foamed asphalt mixtures. Both Marshall stability and indirect tensile strength of foamed asphalt mixtures were about same as those of engineered CIR emulsion mixtures. However, Marshall stability and indirect tensile strength of the vacuum-saturated wet samples of foamed asphalt mixtures were lower than those of engineered CIR emulsion mixtures.


LABORATORY PERFORMANCE TESTING OF OGFC MIXTURES

by

Donald E. Watson (Corresponding Author)



Phone: (334) 844-6228 Fax: (334) 844-6248

E-Mail: [email protected]

L. Allen Cooley, Jr. Burns, Cooley, Dennis, Inc.

(Formerly, National Center for Asphalt Technology) E-mail: [email protected]

Kathryn Ann Moore, P.E.

Graduate Research Assistant, Auburn University E-mail: [email protected]

Kevin Williams



Paper submitted for presentation and publication at the 2004 Annual Meeting of the


Abstract = 220 Text = 4704 Tables/Figures (10 x 250) = 2500 Total Words = 7424


Watson, Cooley, Moore, Williams 1

LABORATORY PERFORMANCE TESTING OF OGFC MIXTURES ABSTRACT Several lab tests were used in this study to evaluate mixture properties. A drain down test, Cantabro stone loss test, permeability test, and a modified version of AASHTO T283 were used to evaluate laboratory performance of the OGFC mixes in this study.

Some of the more pertinent conclusions from this study were (1) The CoreLok procedure appears to be a more accurate method of determining bulk specific gravity of compacted specimens than the dimensional method. (2) The minimum air void content for new-generation OGFC mixtures should be 18 percent based on the dimensional method and 16 percent based on the CoreLok method. (3) The addition of fiber stabilizers significantly reduced the potential for draindown. (4) SGC compacted samples can be used for the Cantabro stone loss procedure. Unconditioned SGC samples should have stone loss of no more than 20 percent. If an aging process is used the maximum amount of stone loss should be limited to 24 percent. Since there is not a significant difference between unaged and aged sample results, the aging procedure is not necessary. (5) Results from this study show no significant difference in tensile strength between 1, 3, or 5 freeze-thaw cycles are used in the moisture conditioning procedure. Therefore, only one freeze-thaw cycle is needed.

Keywords: Open-Graded Friction Course, draindown, Cantabro, CoreLok, permeability, moisture susceptibility.


1

DYNAMIC MODULUS TESTING OF ASPHALT CONCRETE IN INDIRECT TENSION MODE

Y. Richard Kim, Ph.D., P.E. (Corresponding Author)

Professor Dept. of Civil Engineering, Box 7908


Ph: (919) 515-7758 Fax: (919) 515-7908


Youngguk Seo, Ph.D. Postdoctoral Research Associate


Raleigh, NC 27695-7908 Email: [email protected]

Mark King

Graduate Research Assistant Dept. of Civil Engineering, Box 7908



Mostafa Momen Graduate Research Assistant


Raleigh, North Carolina 27695-7908 Email: [email protected]

Submitted for Presentation at the 2004 TRB Annual Meeting and Publication in the Transportation Research Record: Journal of the Transportation Research Board.

Word Count: 7,498 (4,748 words for text, 7 figures, and 4 tables)

November 2003


2

ABSTRACT This paper presents the results from an analytical/experimental study on the dynamic modulus testing of hot mix asphalt (HMA) using the indirect tension (IDT) mode. An analytical solution for the dynamic modulus in the IDT mode is developed using linear viscoelasticity. To verify the analytical solution, temperature and frequency sweep tests were conducted on 12 asphalt mixtures commonly used in North Carolina, using both axial compression and IDT test methods. In doing so, a modified dynamic modulus test protocol is introduced that reduces the required testing time by using more frequencies and fewer temperatures based on the time-temperature superposition principle. A comparison of results from the axial compression and IDT test methods shows that the dynamic modulus mastercurves and shift factors derived from the two methods are in good agreement. It was also found that Poisson’s ratio is a weak function of the loading frequency; its effect on the phase angle mastercurve is discussed. Key words: dynamic modulus, phase angle, shift factor, indirect tension, viscoelastic, axial compression, time-temperature superposition INTRODUCTION The design methods adopted in the AASHTO 2002 Guide for Design of New and Rehabilitated Pavement Structures are based on mechanistic-empirical principles in which the prediction of pavement responses and performance must take into account fundamental properties of layer materials. Among these, the most important property, but a relatively new concept to state highway agencies, is the dynamic modulus of asphalt concrete. This property represents the temperature and frequency (and, therefore, time) dependent stiffness characteristics of the material.

Recently, a significant amount of effort has been given to the development of a test protocol to determine the dynamic modulus of HMA. This effort has resulted in a standard test protocol that can be used for the 2002 AASHTO Design Guide (1). This test protocol calls for the use of axial compression testing for measuring the dynamic modulus.

One of the issues related to the dynamic modulus is its use in forensic studies and pavement rehabilitation design. The current dynamic modulus protocol calls for the axial compression testing of 100 mm diameter and 150 mm tall asphalt concrete specimens. It is often impossible to obtain this size specimen from actual pavements. Given that a typical asphalt layer thickness is less than a few inches and that coring is the most effective method of obtaining specimens from actual pavements, the IDT testing of cores seems to be more appropriate for the evaluation of existing pavements. However, several differences between the axial compression and IDT tests raise questions about the interchangeability of the dynamic modulus values obtained from the two test methods.

Two major differences between these two test methods are: 1. state of stress: Compression testing creates the uniaxial state of stress, whereas the

stress state in the IDT test is biaxial; and


Material Characteristics of Asphalt Rubber Mixtures By Aleksander Zborowski Graduate Research Assistant Arizona State University Department of Civil and Environmental Engineering PO Box 875306, Tempe, AZ 85287-5306 Tel (480)-9655512 e-mail: [email protected] Andres Sotil Graduate Research Assistant Arizona State University Department of Civil and Environmental Engineering PO Box 875306, Tempe, AZ 85287-5306 Tel (480)-9655512 e-mail: [email protected] Kamil E. Kaloush, Ph.D, P.E. Assistant Professor Arizona State University Department of Civil and Environmental Engineering PO Box 875306, Tempe, AZ 85287-5306 Tel (480)-9655509 e-mail: [email protected] and George B. Way, P.E. Chief Pavement Design Engineer Arizona Department of Transportation 1221 North 21st Avenue, MD 068R Phoenix, AZ 85009 Tel (602) 712-8085 e-mail: [email protected] Submitted for Presentation and Publication at the 2004 Annual Meeting of the Transportation Research Board Submission date: August 1st 2003 Word count: 4848 Number of tables: 1 Number of figures: 8


Zborowski, Sotil, Kaloush and Way 2

ABSTRACT This study focused on conducting experimental program on several Asphalt Rubber (AR) mixtures to obtain their typical engineering properties and understand their field performance. Most of the laboratory program was based on tests recommended by the National Cooperative Highway Research Program, NCHRP 9-19 Project, which dealt with recommending Simple Performance Tests (SPT) for the evaluation of asphalt mixes. The laboratory tests included: consistency binder tests, triaxial shear strength, repeated load permanent deformation, dynamic modulus, flexural beam fatigue, and indirect tensile tests. The results obtained for the AR mixtures were also compared, when possible, with results obtained for conventional mixtures.

The AR mixes were those typically used in Arizona, along with an experimental mixture that was constructed by Alberta Transportation, in Canada. All laboratory test specimens were prepared using mixes that were collected during construction. The tests also included sensitivity studies of the mixtures to air voids, temperatures, and influence of confinement level.

It was concluded that many parameters obtained from the above tests were successful in describing the observed good field performance of AR mixes.


Highway Preventive Maintenance Implementation: Comparing Challenges, Processes, and Solutions in Three States

Deborah A. Carroll, Ph.D. Candidate Department of Political Science

University of Wisconsin-Milwaukee 3210 N. Maryland Ave, Bolton Hall 674

Milwaukee, WI 53201 [email protected]

Rita Cheng, Ph.D., CPA, A.O. Smith Professor of Accounting and Associate Dean

School of Business Administration University of Wisconsin-Milwaukee

PO Box 742 Milwaukee, WI 53201

[email protected]

Robert J. Eger III, Ph.D., Assistant Professor

Andrew Young School of Policy Studies Georgia State University

33 Gilmer St., Unit 2 Atlanta, GA 30303-3082

(404) 651-3350 (404) 651-1378 (fax)

[email protected]

Lara Grusczynski, Ph.D. Student Department of Political Science

University of Wisconsin-Milwaukee 3210 N. Maryland Ave, Bolton Hall 674

Milwaukee, WI 53201 [email protected]

Contact Author Justin Marlowe, Ph.D. Candidate

University of Wisconsin-Milwaukee Department of Political Science

3210 N. Maryland Ave., Bolton Hall 664 Milwaukee, WI 53201 Office: (414) 229-5010

Fax: (414) 229-5021 E-mail: [email protected]

Ali Roohanirad, Adjunct Professor

School of Interdisciplinary Computing and Engineering University of Missouri-Kansas City

Hani Titi, Assistant Professor

Department of Civil Engineering and Mechanics University of Wisconsin-Milwaukee

Revised Manuscript Submission Date: November 15, 2003 Revised Manuscript Word Count: 6,923


Carroll, Cheng, Eger, Grusczynski, Marlowe, Roohanirad, and Titi 2

ABSTRACT One of the central challenges facing today’s state transportation policymakers is how to incorporate preventive maintenance concepts and strategies into existing asset management systems. This paper presents case studies of how that incorporation has occurred in the Departments of Transportation in Michigan, Kansas, and Nebraska. It begins by describing seven (7) unique challenges to preventive maintenance implementation identified in the literature and elsewhere, and discusses how states have addressed those challenges through various implementation strategies. The three case studies are then presented in an effort to demonstrate the advantages and disadvantages of these three unique approaches, herein labeled the “top down” approach in Michigan, the “bottom up” approach in Kansas, and the “inclusive” approach in Nebraska. In particular, this paper examines how preventive maintenance concepts were integrated into the planning, budgeting, and technical needs assessment for state highways.


Reduced Confined Dynamic Modulus Testing Protocol for Asphalt Mixtures By Andres Sotil Graduate Research Assistant Arizona State University Department of Civil and Environmental Engineering PO Box 875306, Tempe, AZ 85287-5306 Telephone: (480)-9655512 e-mail: [email protected] Kamil E. Kaloush, Ph.D., P.E. Assistant Professor Arizona State University Department of Civil and Environmental Engineering PO Box 875306, Tempe, AZ 85287-5306 Telephone: (480)-9655509 e-mail: [email protected] and Matthew W. Witczak, Ph.D. Professor Arizona State University Department of Civil and Environmental Engineering PO Box 875306, Tempe, AZ 85287-5306 Tel (480) 965-2759 Fax (480) 727-7058 e-mail: [email protected] Submitted for Presentation and Publication in the 83rd Annual Meeting of the Transportation Research Board Re-submission date: November 15, 2003 Word count: 5131 Number of tables: 1 Number of figures: 7


Sotil, Kaloush and Witczak

2

ABSTRACT The Dynamic Modulus (E*) of Asphalt Mixtures has shown to correlate well to field performance. Studies have also shown that when comparing dense, gap and open graded mixtures, confined E* (C-E*) tests are recommended to rank and compare the expected field performance of the different mixtures. Unfortunately, C-E* tests are harder to perform than unconfined E* (U-E*) tests. Factors like time, availability of equipment, technical complexity, and financial needs must be carefully considered when a confined laboratory-testing program is being proposed.

This objective of this study was to develop a simple method by which C-E* values can be predicted from U-E* results and a reduced number of C-E*-tests. The methods analyzed were developed using E*-test results conducted on nine asphalt rubber mixtures at different confinement levels, and were validated using three conventional dense graded mixes previously tested at Arizona State University.

The U-E* and C-E* test results generally showed a linear relationship with the applied bulk stress, and were almost parallel regardless of the confinement level. An approach to predict C-E* relationship from U-E* test data was developed using one (or two) confined test(s), rather than the five required by the current test protocols. The methods investigated would potentially provide a decrease in laboratory testing time by at least 50%. Since some level of laboratory confinement is recognized for gap and open graded mixes, the methods investigated in this paper may also prove helpful in future development of more accurate pavement distress prediction models.


EVALUATION OF NEW TEST PROCEDURES FOR DETERMINING THE BULK SPECIFIC GRAVITY OF FINE AGGREGATE USING AUTOMATED

METHODS

Brian D. Prowell Assistant Director




Nolan V. Baker Engineering Associate Thompson Engineering 3707 Cottage Hill Road

Mobile, AL 36609 Formerly

National Center for Asphalt Technology


Corresponding Author: Brian D. Prowell Paper No. 04-5196 Word Count: 4,082 words, 5 tables and 3 figures = 6,082 words Submitted for Presentation and Publication at the 83nd Annual Meeting of Transportation

Research Board


Prowell and Baker ii

ABSTRACT

This study evaluated two automated methods for determining the dry bulk specific gravity (Gsb) of fine aggregates, the Thermolyne SSDetect and InstroTek Corelok. Each proposed method was evaluated against the standard method described in AASHTO T-84. The evaluation was based on a round robin study with twelve labs and six materials, four crushed fine and two uncrushed (natural) fine aggregate sources.

The Corelok and SSDetect methods of determining fine aggregate specific gravity offer significant timesavings over AASHTO T84. Both the Corelok and SSDetect methods generally produce Gsb results that are similar to AASHTO T84. It is believed that AASHTO T84 may not produce accurate results for angular materials with high dust contents. More frequent statistical differences exist between both the Corelok and SSDetect apparent specific gravity (Gsa) and water absorption results than those produced by AASHTO T84. However, Gsa and water absorption are not used in volumetric calculations for hot mix asphalt.

The SSDetect offers improved precision to AASHTO T84. The precision of the Corelok method is slightly worse than AASHTO T84, but expected to improve as technicians become more familiar with the procedure.


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