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Office of Infrastructure D R & Pavements Serving the transportation community with innovative pavement technology solutions Turner-Fairbank Highway Research Center
Office ofInfrastructure
DR&Pavements
Serving the
transportation
community with
innovative pavement
technology solutions
Turner-FairbankHighway Research Center
Research
that is essential,
indispensable,
and connected to
our customers
Office ofInfrastructureR&D
The Federal Highway Administration’s (FHWA) Officeof Infrastructure Research and Development (R&D)conducts research that improves the design, con-struction, operation, and management of pavementsand structures. Located at the Turner-FairbankHighway Research Center (TFHRC), the office hasan active outreach program that identifies futuretargets of opportunity, and researchers who pursueadvanced initiatives that drive innovative programsto serve customers’ needs.
Sharing research activities and results with partnersand other interested parties is very important. TheOffice of Infrastructure R&D “spreads the word” andengages the transportation community through pub-lications, meetings, and the TFHRC Web site, andcollaborates with State highway agencies, industrytrade associations, and professional societies.
Pavements
Vision and Goals
The Pavements R&D staff pursues the Agency’svision of long-life pavements that meet our cus-tomers’ needs, are safe, cost effective, long lasting,environmentally friendly, and can be maintainedeffectively. Attaining this vision will help FHWAachieve its key goals of improving the productivityand mobility of the national highway system.
The goal of the Pavements R&D program is toaddress this vision through a series of researchefforts within four broad focus areas:
• Optimized Pavement Design, Materials, andEvaluation Systems.
• Advanced Quality Systems.
• Enhanced User Satisfaction with the DrivingExperience.
• Environmental Stewardship.
Eight TFHRC laboratories support the PavementsR&D program. The Pavements R&D staff works withstakeholders, partners, and other FHWA offices todevelop short- and long-term research, develop-ment, and technology transfer plans and projects;demonstrate new technology; conduct field trials;and address customer needs and potential benefitsfrom new technology.
The Pavements R&D staff is composed of threeteams that work together to develop and conductthe program:
• Pavement Design and Performance Modeling(PDPM).
• Pavement Materials and Construction (PMC).
• Long-Term Pavement Performance (LTPP).
These teams’ products include information, tools,and technology that improve pavement safety, per-formance, and durability, and decrease constructiontime and costs. These attributes enhance user sat-isfaction with the Nation’s pavements. The resultingpavements will be easier to maintain and moreenvironmentally friendly.
Because the teams treat pavements as a system,the resulting interaction and synergy among theteams collectively contribute to the successesachieved in each focus area. All three teams alsosolicit feedback from FHWA’s partners and cus-tomers, and provide technical assistance thatincludes forensic analysis, testing, troubleshooting,and guidance.
Learn more about each team...
Working with
the transportation
community to promote
exchange of information
among researchers,
practitioners, and
infrastructure owners
to provide motorists
with safer, more durable,
environmentally friendly,
and cost-effective
pavement systems with
higher driver satisfaction
PavementDesign andPerformanceModeling Team
The PDPM team develops models,
procedures, and processes that
help transportation specialists predict
pavement performance and select
designs to optimize pavement
performance and life cycle costs.
To accomplish this objective,
researchers consider pavements
as a system; integrating materials
selection and mixture design,
structural design, the construction
process, and environmental exposure.
PavementDesign andPerformanceModeling Team
Activities
Pavement Design Analysis. The PDPM team workswith the American Association of State Highway andTransportation Officials (AASHTO), the NationalCooperative Highway Research Program (NCHRP),other FHWA offices, and State departments of trans-portation (DOT) to evaluate, validate, and calibratethe new pavement design guide developed underNCHRP Project 1-37A. The success of these activitieswill require a collaborative team effort.
Concurrently, the PDPM team is developing additionalmechanistic and mechanistic-empirical models to
advance the state-of-the-art of pave-ment structural behavior predictionand design. For example, recent andcurrent accelerated tests conducted atthe Pavement Testing Facility (PTF) atTFHRC have enhanced our knowledge
about the behavior of Superpave® asphalt mixes andconcrete ultrathin whitetopping. These experimentsare conducted with significant input from and cooper-ation with the paving industry, and provide invaluabledata to verify design models. The PDPM team is alsoworking on new pavement design concepts, includingcomposite pavements, to optimize the use of avail-able paving materials.
In addition, the PDPM team is developing guidelinesfor systematically selecting optimal alternatives forrepair and rehabilitation techniques, consideringpavement condition, desired performance, and cost,among other factors.
Quality Systems. FHWA has developed the HIPERPAV™software system to predict the behavior of concretepavements and avoid problems during construction(for more details, see the PMC team section). As ithas evolved, HIPERPAV now includes a series of predictive models that are relevant to the behaviorand performance of concrete pavements over boththe short and long term. The PDPM team will beworking with HIPERPAV as it relates to pavement performance and design.
The PDPM manages the Computational laboratory,which includes finite element programs to analyzepavement performance.
For more information, please contact the PDPM team leader:Katherine Petros 202–493–[email protected]
PavementMaterials andConstructionTeam
The PMC team helps increase pavement
life by developing a better understanding
of asphalt and portland cement concrete
(PCC) paving materials and the pavement
construction process.
The PMC team is unique in that it is
composed of two groups: the Asphalt
group and the Portland Cement Concrete
group. These groups work independently
on activities unique to their respective
materials, but also routinely work together
to solve problems and advance knowledge
in areas of mutual interest.
Activities
Pavement Design. The PMC team works toenhance the understanding of paving materialscharacteristics, behaviors, and their role in pave-ment performance by investigating them at scalesranging from micro to macro. The microscaleinvolves chemical approaches to characterize andassess modified asphalt bindersystems, detect asphalt antistripping agents (includinglime), investigate alkali-silicareactivity (ASR), and conductforensic investigations for ourState partners.
In the indoor laboratories, the PMC team has arange of activities. Under the Simulation, Imaging,and Mechanics of All Pavements (SIMAP),advanced two- and three-dimensional imagingtechniques (including x-ray tomography) map thecomplex interaction of binders and aggregates.Image analysis identifies and quantifies behaviorsuch as segregation, and advances the state ofperformance models.
The PMC team has developed several key piecesof equipment used for asphalt andconcrete materials testing. The FHWADynamic Angle Validator™ is used inthe Superpave system to calibrategyratory compactors. The coefficientof thermal expansion test provides acharacteristic of concrete key to itsbehavior in concrete pavements.Several other pieces of equipmentare being assessed and refined.
The Superpave system, developed under theStrategic Highway Research Program (SHRP), isbeing further refined through the efforts of thePMC team. Superpave is used nationally forasphalt binder specification and mixture design.The PMC team is conducting an indepth indoorlaboratory and outdoor full-scale study into thebehavior of polymer-modified binders. This effort isbeing coordinated through the TransportationResearch Board’s (TRB) Superpave Binder ExpertTask Group (ETG) and the Superpave Mixture/Aggregate ETG.
At the outdoor full-scale laboratories, 12 full-scalehot-mix asphalt (HMA) test lanes using modifiedbinders have been constructed at the PTF and areundergoing accelerated load tests. This work ispart of national pooled fund project TPF-5 (019)(still open to additional State participants).Results of this study will help engineers across thecountry better select the asphalt binders appropri-ate for increasing the performance and longevityof pavements in their particular climates.
User Satisfaction. To allow traffic on newly con-structed pavements within days or hours after thework is completed, pavement contractors beganusing “fast-track” PCC mixes in the early 1990s.These mixes gain strength rapidly, thus shorteningthe time delay caused by pavement curing. As aresult, fast-track construction improves highwayuser satisfaction by minimizing the delays causedby construction activities.
The challenge associated with these rapidstrength-gain concretes is to place them success-fully to achieve long-term durability and rapidstrength. In response to this problem, FHWAbegan researching construction guidelines for fast-track jointed plain concrete pavements.Researchers developed the software programHIPERPAV to help control pavement quality duringconstruction. HIPERPAV uses predictive models toconsider design, selection of pavement materials,construction, and environmental factors and torecommend select combinations of variableswithin these factors that will resist early-age dis-tress. Research continues on HIPERPAV to expandits capabilities.
Intelligent construction systems use state-of-the-art technology to streamline and increase thequality of the construction process. The PMCteam is currently exploring the use of smart compaction systems that incorporate a globalpositioning system, density sensors, and a computer graphics interface to help the rolleroperators optimize the compaction of base andasphalt-bound pavement layers.
Quality Systems. The macroscale deals with activi-ties that have a direct impact on the constructionprocess. The PMC team works with the TRB’sSuperpave committee to develop quality assur-ance/quality control guidelines for pavement con-struction projects. Researchers are developing andvalidating HMA performance-related specifications(PRS) in cooperation with NCHRP project 9-22. Inaddition, the team is exploring alternative non-nuclear devices to determine mix compaction anddensity during HMA construction, and evaluationof one such device is currently underway.
For rigid pavements, PRS researchhas produced the PaveSpec™ soft-ware package that helps pavementspecifiers develop their own PRS;the specifications have been testedon several projects in Indiana, withother projects pending.
The PMC team manages the Asphalt Mixtures laboratory, Binder laboratory, Chemistry laboratory,PCC laboratory complex, Petrographic laboratory,PTF, and the SIMAP laboratory.
For more information, please contact the PMC team leader: Tom Harman202–493–[email protected]
Long-TermPavementPerformanceTeam
The LTPP team conducts the LTPP
program to increase the understanding
of why some pavements perform better
than others. This information is key to
building and maintaining a cost-effective
highway system.
Long-TermPavementPerformanceTeam
Activities
Pavement Design. In 1987, the LTPP program—acomprehensive 20-year study of inservice pave-ments—began a series of rigorous long-term fieldexperiments monitoring more than 2,400 asphaltand PCC pavement test sections across theUnited States and Canada. These sectionsincluded both existing pavements (GeneralPavement Studies) and newly constructed sec-tions (Specific Pavement Studies).
NCHRP Project 1-37A has developed a new pave-ment design guide. Data collected at the LTPPsites since the program’s inception have beenessential for evaluating and validating the modelsincluded in the new guide. LTPP data will continueto be used for further evaluation and validation ofthe guide.
A new pooled fund study, TPF 5 (039), is being offeredto interested States. Objectivesof the study, “Falling WeightDeflectometer (FWD)Calibration Center and
Operational Improvements,” include minimizingthe variability in pavement-deflection dataobtained with FWDs and developing and imple-menting long-term plans for FWD calibrationcenters.
User Satisfaction. The LTPP team recently com-pleted a study of pavement smoothness indexrelationships to improve pavement evaluation anddata comparisons. The correlations developedbetween Profile Indices and InternationalRoughness Indices will allow States to convertfrom one system of measurement to another andstill make use of archived data.
The results of this studyand other LTPP efforts willimprove monitoring ofLTPP sections and otherpavements. This will leadto improved qualitycontrol during pavement construction, improvedpavement performance, and, ultimately, enhancedsatisfaction among highway users.
Quality Systems. In addition to managing the LTPPprogram to its completion, the LTPP team is col-lecting, formatting, storing, and analyzing data onthe characteristics and performance of pavingmaterials and pavements, in support of the activi-ties of the other two pavement teams. Work willinclude using new equipment and procedures tocollect information, and developing a more user-friendly framework to store and retrieve data,allowing easy access for multiple uses.
LTPP Data Availability
Standard Data ReleaseLTPP has developed a new “Standard DataRelease,” which is a set of CD-ROMs containingthe most current pavement performance data inzipped Microsoft® Access® 2000 database files.Also included is an application called TableNavigator, which helps the user understand thecontents of the release by combining referencedocuments into a searchable database. A manualfor Table Navigator also is included. To obtain acopy of the current Standard Data Release, pleasecontact the LTPP Customer Support Service Centerat [email protected], by calling865–481–2967, or by faxing 865–481–8555.
DataPave OnlineDataPave Online is the latest effort to expandaccess to the LTPP pavement performance datawhile providing a user-friendly graphical interface.DataPave is available at http://www.datapave.com.The data provided in DataPave online will be thesame as that delivered with the new StandardData Release, described above; however, dataupdates on the Web site may lag somewhatbehind the Standard Data Release as data istransferred between the two media.
For more information, please contact the LTPP team leader:Aramis López202–493–[email protected]
For more information, contact:Office of Infrastructure R&D
Stephen ForsterTechnical Director for Pavements
202–493–[email protected]
Paul TengDirector
202–493–[email protected]
Visit us on the Web at:www.tfhrc.gov
FHWA-RD-03-090
HRDI-04/08-04(2.5M)E
