+ All Categories
Home > Documents > Module 2-5 Field Sampling and Testing. Identify reasons for conducting field sampling and lab...

Module 2-5 Field Sampling and Testing. Identify reasons for conducting field sampling and lab...

Date post: 23-Dec-2015
Category:
Upload: daniela-kelley
View: 224 times
Download: 1 times
Share this document with a friend
Popular Tags:
32
Module 2-5 Module 2-5 Field Sampling and Field Sampling and Testing Testing
Transcript
Page 1: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Module 2-5Module 2-5

Field Sampling and Field Sampling and TestingTesting

Page 2: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Identify reasons for conducting field Identify reasons for conducting field sampling and lab testing sampling and lab testing

Describe typical Describe typical fieldfield sampling and testing sampling and testing proceduresprocedures

Describe Describe laboratorylaboratory test methods and test methods and their applicationstheir applications

Describe the use of field and laboratory Describe the use of field and laboratory test results in rehabilitation designtest results in rehabilitation design

Learning ObjectivesLearning Objectives

Page 3: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Reasons for Conducting Reasons for Conducting Field Sampling and Lab Field Sampling and Lab

TestingTesting Complement and verify NDTComplement and verify NDT

Absence of NDTAbsence of NDT

Diagnose causes (mechanisms) of distressDiagnose causes (mechanisms) of distress

Identify structural characteristics and layer Identify structural characteristics and layer material properties in existing pavementmaterial properties in existing pavement EconomicsEconomics RecyclingRecycling Emphasis on rehabilitationEmphasis on rehabilitation

Page 4: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Typical Field Sampling and Typical Field Sampling and Testing ProceduresTesting Procedures

Material specimen samplingMaterial specimen sampling CoringCoring AugerAuger Split-spoonSplit-spoon Shelby (push) tubeShelby (push) tube Test pitTest pit

Field testingField testing Dynamic cone penetrometer (DCP)Dynamic cone penetrometer (DCP) Ground penetrating radar (GPR)?Ground penetrating radar (GPR)?

Page 5: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

CoringCoring Widely used method for:Widely used method for:

Laboratory test samplesLaboratory test samples Layer thickness determination (or Layer thickness determination (or

verification)verification) Visually characterizing layer material Visually characterizing layer material

types and conditionstypes and conditions

Relatively inexpensiveRelatively inexpensive

Coring plans used to assess variability Coring plans used to assess variability along a project along a project

Page 6: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

CoringCoringRemoving a CoreRemoving a Core

Page 7: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

CoringCoringLayer Thickness VerificationLayer Thickness Verification

Page 8: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

CoringCoringDistress Cause IdentificationDistress Cause Identification

Page 9: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

CoringCoringSampling ApproachesSampling Approaches

Uniform spacing, e.g., every 500 m Uniform spacing, e.g., every 500 m

Based on review of “strip” charts

Distance Along Roadway

Page 10: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

CoringCoringSampling Locations and Sampling Locations and

FrequencyFrequency

Standard locationStandard location Outside laneOutside lane Outer wheel pathOuter wheel path

Frequency (no. of samples) depends on:Frequency (no. of samples) depends on: Variability (uncertainty)Variability (uncertainty) Project size (anticipated rehab cost)Project size (anticipated rehab cost) Traffic and safety issuesTraffic and safety issues

Typical spacing: 100 to 800 mTypical spacing: 100 to 800 m

Page 11: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Dynamic Cone Dynamic Cone Penetrometer (DCP)Penetrometer (DCP)

Device for measuring in-situ strength of Device for measuring in-situ strength of paving materials and subgrade soilspaving materials and subgrade soils

Correlated to California Bearing Ratio Correlated to California Bearing Ratio (CBR)(CBR)

Page 12: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Cone angle 60o

Handle

Hammer(17.6 lb)

Cone

Steel rod (0.64 in)

22.6 in

39.4 in(variable)

1 in = 25.4 mm1 lb = 0.454 kg

0.79 in

DCP DeviceDCP Device

Page 13: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

DCP Testing ProcessDCP Testing Process

Page 14: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Example DCP ResultsExample DCP Results

No. of BlowsNo. of Blows

DepthDepth

Base

HMA

Subbase

Subgrade Soil

Page 15: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Ground Penetrating Radar Ground Penetrating Radar (GPR)(GPR)

HMAHMA

BaseBase

SubbaseSubbase

Subgrade SoilSubgrade Soil

GPR Transmitter/ReceiverGPR Transmitter/Receiver Conceptual OutputConceptual Output

Page 16: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Laboratory Test Methods Laboratory Test Methods and Their Applicationsand Their Applications

Type of materialType of material

Basic property being measuredBasic property being measured

Material’s state of stressMaterial’s state of stress

Test methods (and their applications) areTest methods (and their applications) are

dependent upon:dependent upon:

Page 17: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Typical Properties Typical Properties Measured in LabMeasured in Lab

GeneralGeneralPropertyProperty Various Test MeasuresVarious Test Measures

StiffnessStiffness MMRR, E*, R-value, E*, R-value

StrengthStrength CBR, indirect tension, CBR, indirect tension, unconfined compressionunconfined compression

CompactionCompaction , AVC, AVC

ConstituentsConstituents , AC, gradation, contaminants, AC, gradation, contaminants

PermeabilityPermeability kk

Volume StabilityVolume Stability PI, PI,

Page 18: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Resilient ModulusResilient Modulus Surrogate for Young’s Surrogate for Young’s

(elastic) modulus(elastic) modulus

Fundamental Fundamental engineering propertyengineering property

Loading conditions:Loading conditions:

EEMMRR

Triaxial compressionTriaxial compression Axial compressionAxial compression Indirect tensionIndirect tension

Page 19: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Resilient Modulus TestResilient Modulus TestTriaxial CompressionTriaxial Compression

Used primarily for Used primarily for testing of unbound testing of unbound materials materials (re-compacted (re-compacted specimens or push specimens or push tube samples)tube samples)

Page 20: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Resilient ModulusResilient ModulusMethod of DeterminationMethod of Determination

Strain,

Dev

iato

r S

tres

s,

D

PlasticStrain

ResilientStrain

Total Strain

P R

MR =D

R

Page 21: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Resilient Modulus TestResilient Modulus TestAxial CompressionAxial Compression

Used primarily Used primarily for testing of for testing of bound materials bound materials (prepared (prepared specimens or specimens or core samples)core samples)

OEM, Inc. © 2000

LoadLoadRamRamLoad Load

CellCell

LVDTLVDTGage LengthGage Length

Heavier duty test equipment is used Heavier duty test equipment is used to measure compressive strengthto measure compressive strength

Page 22: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Complex Modulus (E*)Complex Modulus (E*) a.k.a.: dynamic modulusa.k.a.: dynamic modulus

Applicable to bituminous materialsApplicable to bituminous materials

Equipment and test procedure almost Equipment and test procedure almost identical to resilient modulus under axial identical to resilient modulus under axial compressioncompression

Primary difference is in load pulse Primary difference is in load pulse (haversine vs. sinusoidal)(haversine vs. sinusoidal)

AASHTO 2002 Guide for Design of New AASHTO 2002 Guide for Design of New and Rehabilitated Pavement Structuresand Rehabilitated Pavement Structures

Page 23: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Hveem Resistance TestHveem Resistance Test(R-value) (R-value)

Stiffness measure for Stiffness measure for unbound materialsunbound materials

Standard axial stress Standard axial stress ((vv) is applied) is applied

R-value is basically the R-value is basically the ratio of the applied ratio of the applied vertical pressure (vertical pressure (vv) to ) to the developed lateral the developed lateral pressure (pressure (hh))

vv

hh

150150mmmm

100 mm100 mm

Page 24: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

California Bearing Ratio California Bearing Ratio (CBR) Test(CBR) Test

Strength measure for Strength measure for unbound materialsunbound materials

Piston advanced at Piston advanced at 1.3 mm / min. rate1.3 mm / min. rate

Measure load at 2.5 Measure load at 2.5 mm penetration (Pmm penetration (P2.52.5))

CBR = 100CBR = 100(P(P2.52.5/P/Pstdstd))

SaturatedSaturatedSpecimenSpecimen

50 mmdiameter

piston

150 mm

180mm

Page 25: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Indirect Tension TestIndirect Tension Test a.k.a.: Splitting tension or split tensile testa.k.a.: Splitting tension or split tensile test

Used to determine the tensile strength Used to determine the tensile strength and/or Mr of any bound materialand/or Mr of any bound material

100 or 150 mm diameter (D) 100 or 150 mm diameter (D) specimensspecimens

Sample length should be Sample length should be at least half the diameter at least half the diameter

Prepared samples or coresPrepared samples or cores

v

r D

Load, P

Length

Page 26: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Evaluating Pavement Evaluating Pavement LayersLayers

Subgrade SoilsSubgrade Soils

Soil classification (Unified or AASHTO)Soil classification (Unified or AASHTO)

Moisture content and densityMoisture content and density

DCPDCP

Resilient modulus:Resilient modulus: Measure in the labMeasure in the lab Backcalculate from NDT dataBackcalculate from NDT data Estimated from correlation with R-Estimated from correlation with R-

value, CBR, or other soil propertiesvalue, CBR, or other soil properties

Page 27: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Evaluating Pavement Evaluating Pavement LayersLayers

Unbound Base & Subbase LayersUnbound Base & Subbase Layers

Visual inspectionVisual inspection Layer thicknessLayer thickness Degradation or contamination by finesDegradation or contamination by fines

DCPDCP

Density and moisture contentDensity and moisture content

Resilient modulusResilient modulus

Page 28: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Evaluating Pavement LayersEvaluating Pavement LayersHMA Surface and Stabilized Base LayersHMA Surface and Stabilized Base Layers

Visual inspection of coresVisual inspection of cores Layer thicknessLayer thickness Stripping, segregation, erosionStripping, segregation, erosion

Asphalt content and gradationAsphalt content and gradation

Resilient modulusResilient modulus Lab measured (indirect tension)Lab measured (indirect tension) BackcalculatedBackcalculated

Page 29: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Other ConsiderationsOther Considerations Volume stabilityVolume stability

StrippingStripping

Seasonal variations in moistureSeasonal variations in moisture

PermeabilityPermeability

Page 30: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Use of Field and Lab Tests Use of Field and Lab Tests in Rehabilitation Designin Rehabilitation Design

Help characterize existing support and Help characterize existing support and quantify effect of deteriorationquantify effect of deterioration

Field and lab testing vary depending on:Field and lab testing vary depending on: Material type (i.e., subgrade soil, Material type (i.e., subgrade soil,

unbound base or subbase, and HMA unbound base or subbase, and HMA surface or stabilized base)surface or stabilized base)

Candidate types of rehabilitation Candidate types of rehabilitation treatments (for example, recycling treatments (for example, recycling justifies a higher level of lab testing)justifies a higher level of lab testing)

Page 31: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

What are two situations where field What are two situations where field sampling and lab testing may be sampling and lab testing may be required?required?

What kind of sampling and testing would What kind of sampling and testing would you now consider?you now consider?

What is the motivation for resilient What is the motivation for resilient modulus testing?modulus testing?

Name two ways in which field/lab test Name two ways in which field/lab test results can be used in rehab design?results can be used in rehab design?

ReviewReview

Page 32: Module 2-5 Field Sampling and Testing.  Identify reasons for conducting field sampling and lab testing  Describe typical field sampling and testing.

Key ReferencesKey References Washington State Department of Washington State Department of

Transportation (WSDOT). 1995. Transportation (WSDOT). 1995. WSDOT Pavement Design GuideWSDOT Pavement Design Guide. . Washington State Department of Washington State Department of Transportation, Olympia, WA.Transportation, Olympia, WA.

Livneh, M. 1987. “The Use of Dynamic Livneh, M. 1987. “The Use of Dynamic Cone Penetrometer in Determining the Cone Penetrometer in Determining the Strength of Existing Pavements and Strength of Existing Pavements and Subgrades.” Subgrades.” Proceedings, 9Proceedings, 9thth Southeast Southeast Asian Geotechnical Conference.Asian Geotechnical Conference. Bangkok, Thailand.Bangkok, Thailand.


Recommended