Instructor’s Guide
Module 2-5. Field Sampling and Testing
MODULE 2-5
FIELD SAMPLING AND TESTING
HMA Pavement Evaluation and Rehabilitation
2-5.1
Instructor’s Guide
Module 2-5. Field Sampling and Testing
NOTES
2-5.2
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Module 2-5. Field Sampling and Testing
MODULE 2-5
FIELD SAMPLING AND TESTING
Instructional Time: 45 minutes
Presentation File: HMA Module 02-05.ppt
Overview
This module describes procedures for conducting an effective field sampling, field testing, and laboratory
testing program. This can be a key component in an overall project level evaluation process, especially
when there is uncertainty in the layer conditions and properties of the existing pavement.
Learning Objectives
At the conclusion of this module, the participant should be able to accomplish the following:
1. Explain the purpose of conducting field sampling and testing.
2. Describe typical field sampling and testing procedures.
3. Describe commonly used laboratory test methods and their applications.
4. Describe the use of field and laboratory test results as part of the rehabilitation design process.
Participant Review Questions and Answers
1. What are two situations where field sampling and lab testing may be required?
Field sampling and laboratory testing is commonly used to:
 Complement NDT data. NDT will not provide data regarding layer thicknesses, moisture
content, and density. Coring provides (confirms) the layer thickness information needed for
backcalculation as well as material samples needed to help explain areas of high (or low)
deflection. Field and lab testing can help improve (or validate) the backcalculation results.
 Provide information in the absence of NDT data. In the absence of any project level NDT
data, a thorough laboratory testing program is essential. It provides the data needed to
adequately characterize the material properties and support conditions of the existing
pavement.
 Identify causes of distress. Field sampling is used to determine the cause of distresses such as
rutting, fatigue cracking, thermal cracking, raveling, stripping, bleeding, and shoving.
 Characterize the structural and materials properties of the pavement.In recent years the
importance of adequately characterizing the structural characteristics of the existing
pavement, prior to evaluating various rehabilitation alternatives, have been widelyrecognized. Although economics is often the driving force behind these efforts, other factors
HMA Pavement Evaluation and Rehabilitation
2-5.3
Instructor’s Guide
Module 2-5. Field Sampling and Testing
such as the increased emphasis on recycling and the increased emphasis on rehabilitating
existing pavement networks are also credited.
2. What kind of sampling and testing would you now consider?
This is an open-ended question to the course participants asking them to compare their current
sampling and testing practices with the methods presented in this module. Some of the sampling and
testing methods that should be considered include the following:
 Material specimen sampling. These include coring, augering, split-spoon sampling, Shelby
(push) tube sampling, and test pits.
 Field testing. Common field testing methods include use of the dynamic cone penetrometer
(DCP) and ground penetrating radar (GPR).
 Laboratory testing. Common laboratory testing methods include testing for resilient modulus,
complex modulus, Hveem resistance, California bearing ratio (CBR), and indirect tensile
strength.
3. What is the motivation for resilient modulus testing?
Resilient modulus is a closely-related surrogate for Young’s (elastic) modulus. Young’s modulus (E)
represents the relationship between stress and strain for linear elastic materials. Most pavement
materials are non-linear. Thus, resilient modulus represents the best estimate of Young’s along a
non-linear relationship between applied stress and strain. Young’s modulus (and to a large extent,
resilient modulus) represent a fundamental property of the material.
4. Name two ways in which field/lab test results can be used in rehabilitation design?
The primary purposes of this field and laboratory investigation are to calibrate/verify NDT data,
provide material information where NDT data is not available, and help determine the causes of any
observed pavement deficiencies. When conducting an evaluation for pavement rehabilitation, the
focus of all sampling and testing is to facilitate the selection of the most appropriate rehabilitation
technique. Such sampling and testing methods greatly help the engineer in making final
rehabilitation technique recommendations by 1) determining material details, and 2) estimating the
variability of material differences along a pavement. In addition, such sampling and testing may
provide material properties that are required by some of the modern mechanistic pavement design
procedures.
Pitfalls
None.
Discussion Points
None.
2-5.4
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Module 2-5. Field Sampling and Testing
Areas to Reduce if Time Constraints Exist
Time can be saved by not going into as much detail on the different laboratory test methods as is available
in the slide notes.
Associated Workshop
None.
HMA Pavement Evaluation and Rehabilitation
2-5.5
Module 2-5. Field Sampling and Testing
Instructor’s Guide
Presentation Graphics and Instructor’s Notes
Slide
1
Module 2-5
Field Sampling and
Testing
Slide
2
Learning Objectives
This module addresses issues associated
with conducting a valid field sampling,
field testing and laboratory testing
program. This can be a key component in
an overall project level evaluation process,
especially when there is uncertainty in
existing pavement layer characteristics
and/or nondestructive testing is not an
option.
Upon completing this module, the
participants should able to accomplish the
items listed here.
 Identify reasons for conducting field
sampling and lab testing
 Describe typical field sampling and testing
procedures
 Describe laboratory test methods and
their applications
 Describe the use of field and laboratory
test results in rehabilitation design
Slide
3
Reasons for Conducting Field
Sampling and Lab Testing
 Complement and verify NDT
 Absence of NDT
 Diagnose causes (mechanisms) of distress
 Identify structural characteristics and layer
material properties in existing pavement
 Economics
 Recycling
 Emphasis on rehabilitation
2-5.6
These items drive the need to accurately
characterizing the structural and materials
properties of the pavement.
 Complement NDT Data. NDT will not
provide data regarding layer
thicknesses, moisture content, and
density. Coring provides (confirms)
the layer thickness information needed
for backcalculation as well as material
samples needed to help explain areas of
high (or low) deflection. Field and lab
testing can help improve (or validate)
the backcalculation results.
 Absence of NDT Data. In the absence
of any project level NDT data, a
thorough laboratory testing program is
essential. It provides the data needed to
adequately characterize the material
properties and support conditions of the
existing pavement.
 Distress Type. Field sampling is used to
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Module 2-5. Field Sampling and Testing
determine the cause of distresses such
as rutting, fatigue cracking, thermal
cracking, raveling, stripping, bleeding,
and shoving.
 In recent years the importance of
adequately characterizing the structural
characteristics of the existing
pavement, prior to evaluating various
rehabilitation alternatives, have been
widely-recognized. Although
economics is often the driving force
behind these efforts, other factors such
as the increased emphasis on recycling
and the increased emphasis on
rehabilitating existing pavement
networks are also credited.
Slide
4
Typical Field Sampling and
Testing Procedures
 Material specimen sampling
 Coring
 Auger
 Split-spoon
 Shelby (push) tube
 Test pit
 Field testing
 Dynamic cone penetrometer (DCP)
 Ground penetrating radar (GPR)?
HMA Pavement Evaluation and Rehabilitation
1. Specific sampling techniques to obtain
material specimen samples include:
 Coring allows the engineer to obtain
a cross section of all pavement
layers (low disturbance).
 Augers are used primarily to collect
granular material samples (high
disturbance).
 Split spoon sampling is most suited
for the sampling of fine-grained
soils (medium disturbance).
 Shelby tubes are used to collect
sample fine and some coarsegrained soils (low disturbance).
 Test pits (or trenches) are used to
collect and test “undisturbed”
samples of all subsurface layers.
2. Field testing associate with a thorough
project-level evaluation:
 There is one field test procedure that
permits an in-situ assessment of the
soil strength. The dynamic cone
penetrometer basically measures the
material’s resistance to penetration.
It has been shown to be correlate
well with a measure of soil stiffness,
i.e., resilient modulus.
 GPR is used primarily to measure
(or confirm) pavement layer
thicknesses.
2-5.7
Module 2-5. Field Sampling and Testing
Slide
5
Coring
 Widely used method for:
 Laboratory test samples
 Layer thickness determination (or
verification)
 Visually characterizing layer material
types and conditions
 Relatively inexpensive
 Coring plans used to assess variability
along a project
Slide
6
Slide
7
2-5.8
Coring
Removing a Core
Coring
Layer Thickness Verification
Instructor’s Guide
 Coring provides two other major
benefits besides providing samples for
lab testing.
 As a destructive sampling procedure,
coring is relatively inexpensive. The
associated traffic control can be much
more expensive.
 Typically, coring plans are designed to
gather as much information as possible
to measure or explain variability along
project.
These two photographs illustrate the
process of cutting a core using a truck
mounted coring rig. Heavier duty
equipment (such as that shown) can
expedite the coring process and minimize
delay to the road users.
 Cores are cut from the pavement using
diamond-tipped cylindrical (hollow)
core barrels.
 Core barrels are typically 100 or 150
mm (4 or 6 in) in diameter.
 Water is used to lubricate the barrel.
This slide illustrates the use of coring to
verify different layer thicknesses.
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Module 2-5. Field Sampling and Testing
Slide
8
Coring
This slide shows a core hole, in which
there are signs of asphalt stripping below.
Distress Cause Identification
Slide
9
Coring
Sampling Approaches
 Uniform spacing, e.g., every 500 m
 Based on review of “strip” charts

Distance Along Roadway
Slide
10
Coring
Sampling Locations and Frequency
 Standard location
 Outside lane
 Outer wheel path
 Frequency (no. of samples) depends on:
 Variability (uncertainty)
 Project size (anticipated rehab cost)
 Traffic and safety issues
 Typical spacing: 100 to 800 m
HMA Pavement Evaluation and Rehabilitation
Two primary methods for identifying core
locations have been used:
 The uniform spacing approach is used
when there is little information to
indicate variability. For example,
records indicate that the project is of a
uniform thickness and soil support
condition throughout. Similarly, the
condition does not change from start to
end. Also, NDT data was not collected.
 When information demonstrating
project variability, i.e., NDT variability,
structural changes, cut/fill differences,
core locations should be located at
points where the differences occur.
1. For HMA pavements, cores are
typically taken in the outer wheel path
of the outer lane. This is the area
where deterioration tends to develop
first. Sometimes, cores are taken
between the wheel paths to attempt to
measure the original properties.
2. The number of samples is affected by:
 The apparent variability in the
project (more variability means
more samples).
 The size (or anticipated cost of
rehabilitation) for the project (more
investment at stake justifies greater
expense for sampling).
 The amount of traffic being affected
and safety issues associated with
confining or detouring traffic (major
impacts on traffic can kill a coring
2-5.9
Instructor’s Guide
Module 2-5. Field Sampling and Testing
program).
 Under a uniformly spaced coring
program, the spacing of the core
locations can range from 100 to 800
m (300 to 2500 ft). The spacing of
cores in a typical rigorous sampling
program is between 150 and 300 m
(500 and 1000 ft).
Slide
11
Dynamic Cone Penetrometer
(DCP)
 Device for measuring in-situ strength of
paving materials and subgrade soils
 Correlated to California Bearing Ratio
(CBR)
Slide
12
DCP Device
Handle
 The DCP is a device for measuring the
in situ strength of subsurface layers and
subgrade soils.
 Currently, DCP testing procedures are
being developed in an ASTM
subcommittee.
 The DCP penetration rate (PR) can be
used to identify pavement layer
boundaries and subgrade strata, and to
estimate the CBR values of those
layers.
Shown here are the key statistics of a
manual DCP.
Hammer
(17.6 lb)
Cone angle 60o
22.6 in
0.79 in
1 in = 25.4 mm
1 lb = 0.454 kg
39.4 in
(variable)
Steel rod
(0.64 in)
Cone
Slide
13
2-5.10
DCP Testing Process
The DCP test is performed by driving the
cone into the pavement/subgrade by
raising and dropping the hammer. The
cone penetration is recorded for each drop
and termed the penetration rate.
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Slide
14
Module 2-5. Field Sampling and Testing
Example DCP Results
No. of Blows
HMA
Base
Subbase
Depth
Slide
15
Subgrade Soil
Ground Penetrating Radar
(GPR)
GPR Transmitter/Receiver
Conceptual Output
HMA
Base
Subbase
Subgrade Soil
Slide
16
Shown here (conceptually) are the
graphical results of the DCP. Each data
point represents the number of drops
required to travel a given distance at a
given depth. Measurements are taken at
pre-selected depths within the pavement
substructure to characterize the subsurface
strength profile.
Laboratory Test Methods
and Their Applications
Test methods (and their applications) are
dependent upon:
 Type of material
 Basic property being measured
 Material’s state of stress
HMA Pavement Evaluation and Rehabilitation
Another tool which has been used to
measure pavement layer thickness
variability is ground penetrating radar.
Interfaces between subsurface layers act as
surfaces for reflecting radar pulses. The
feedback is plotted as the device travels
down the road. The output shown here is
over simplified for the sake of explanation.
Interpreting GPR output takes experience.
Because of changes from site to site, the
device itself is almost always calibrated
against a section of known layer
thicknesses.
Lab tests are performed on field samples
obtained from the pavement structure for a
number of reasons (that will be discussed
later). The types of tests performed are
dependent upon:
 Type of material – Is it bound or
unbound? Is it a surface or subsurface
layer?
 Property being measured – Obviously,
a test designed to measure material
strength will not be useful for
measuring its permeability.
 Material’s state of stress – If this can
affect the property being measured,
certain lab tests are designed to
simulate the in-situ stress conditions.
2-5.11
Module 2-5. Field Sampling and Testing
Slide
17
Typical Properties
Measured in Lab
General
Property
Stiffness
Strength
2-5.12
Various Test Measures
MR, E*, R-value
CBR, indirect tension,
unconfined compression
Compaction
, AVC
Constituents
, AC, gradation, contaminants
Permeability
k
Volume Stability
PI, 
Instructor’s Guide
1. This table lists the general material
properties that can be measured in the
lab and which are related to pavement
layer materials characterization. For
each general property class, there are
one or more specific test measures
designed to quantify it.
 Stiffness – There are three typical
measures of material stiffness
(resistance to deformation) that have
been use for HMA pavement-related
applications, resilient modulus,
dynamic modulus and R-value.
(These will be discussed in more
detail later).
 Strength – The California Bearing
Ratio (CBR) test, the indirect
tension test and the unconfined
compression test are the three
primary test methods that have been
used to measure material strength in
an HMA pavement structure. The
first two of these will be discussed
in more detail later. The unconfined
compression test provides an
estimate of the strength of a
stabilized subsurface pavement
layer. Because of it limited
application, it will not be addressed
here in any more detail. It should be
noted that pavements are designed
to operate at stress levels well below
the strengths of the materials
(particularly for subsurface layers),
material strength is not as important
a factor as stiffness.
2. It is assumed that the participants will
have much more familiarity with the
following general properties and their
related test procedure. Accordingly,
beyond this point, very little additional
detail is provided.
 Compaction – Density is the
standard measure for compaction
adequacy for subsurface layers. Air
void content is the standard for the
bituminous surface layers.
 Constituents – Moisture content
(subsurface layers), asphalt content
(HMA surface layers), gradation (all
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Module 2-5. Field Sampling and Testing
layers), contaminants (intrusion of
fines into subbase).
 Permeability – Rate at which
moisture travels through any given
layer. Permeability is desirable for
good drainage in subsurface layers.
High permeability is undesirable
characteristic in an HMA surface
layer.
 Volume stability – Plasticity index
(a measure of the expansive nature
of a fine-grained material as it
absorbs moisture). Thermal
coefficient (a measure of a
material’s propensity to expand and
contract with changes in
temperature).
Slide
18
Resilient Modulus
 Surrogate for Young’s
(elastic) modulus
 Fundamental
engineering property

E
 Loading conditions:
Slide
19

Triaxial compression

Axial compression

Indirect tension
MR
Resilient Modulus Test
Triaxial Compression
Used primarily for
testing of unbound
materials
(re-compacted
specimens or push
tube samples)
HMA Pavement Evaluation and Rehabilitation

What is resilient modulus?
1. It is a closely-related surrogate for
Young’s (elastic) modulus. Young’s
modulus, E (shown in the figure),
represents the relationship between
stress and strain for linear elastic
materials. Most pavement materials are
non-linear. Thus, resilient modulus
represents the best estimate of Young’s
along a non-linear relationship between
applied stress and strain.
2. Young’s modulus (and to a large
extent, resilient modulus) represent a
fundamental property of the material.
3. Resilient modulus can be measured
under one of three different loading
conditions.
Photograph of resilient modulus test
apparatus shows pneumatic chamber (for
application of confining pressure), sample
mounts, LVDTs, load ram (for application
of axial load) and load cell.
2-5.13
Instructor’s Guide
Module 2-5. Field Sampling and Testing
Slide
20
This figure illustrates the part of a typical
loading and unloading stress strain curve
that is used to determine the resilient
modulus. Note that the plastic strain
portion of the loading curve is not
considered.
Resilient Modulus
Method of Determination
Deviator Stress,
D
Total Strain
Plastic
Strain
P
Resilient
Strain
R
MR =
D
R
Strain, 
Slide
21
Resilient Modulus Test
Axial Compression
 Used primarily
for testing of
bound materials
(prepared
specimens or
core samples)
Load
Ram
Load
Cell
Gage Length
LVDT
OEM, Inc. © 2000
 Heavier duty test equipment is used
to measure compressive strength
 Photo illustrates resilient modulus test
apparatus for bound materials, typically
HMA and PCC. Simpler heavy duty
equipment is used to load the sample to
failure and measure their compressive
strength.
 The problem with this type of lab
equipment, especially for cores from
HMA pavements, is that the height
needs to be twice the diameter. (This is
one of the reasons why the splitting
tension test has become more popular).
Note: this is the testing machine that is
used to conduct testing in accordance with
AASHTO T292-96, Resilient Modulus of
Subgrade Soils and Untreated
Base/Subbase Materials. It is not the same
testing apparatus used for testing in
accordance with AASHTO T307-99,
Determining the Resilient Modulus of Soils
and Aggregate Materials. The testing
apparatus used in accordance with
AASHTO T307-99 uses vertical LVDTs.
AASHTO T307-99 is currently viewed as
the accepted standard by FHWA.
2-5.14
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Slide
22
Module 2-5. Field Sampling and Testing
Complex Modulus (E*)
 a.k.a.: dynamic modulus
 Applicable to bituminous materials
Complex modulus is also a surrogate for
resilient modulus. It is geared primarily
for HMA surface layers and is intended to
replace HMA resilient modulus (2002
AASHTO Guide).
 Equipment and test procedure almost
identical to resilient modulus under axial
compression
 Primary difference is in load pulse
(haversine vs. sinusoidal)
 AASHTO 2002 Guide for Design of New
and Rehabilitated Pavement Structures
Schematic diagram of Hveem’s R-value
test. Many western states use this test to
characterize their soil and base materials.
Slide
23
Slide
24
California Bearing Ratio
(CBR) Test
50 mm
diameter
piston
180
mm
Saturated
Specimen
 Strength measure for
unbound materials
 Piston advanced at
1.3 mm / min. rate
 Measure load at 2.5
mm penetration (P2.5)
 CBR = 100(P2.5/Pstd)
150 mm
HMA Pavement Evaluation and Rehabilitation
 The first strength-related laboratory test
is the California Bearing Ratio (CBR)
test.
 This is a schematic diagram illustrating
the many details of the CBR test.
 Conversions: 180 mm = 7 in; 150 mm
= 6 in; 50 mm = 1.95 in; 1.3 mm/min =
0.05 in/min; 2.5 mm = 0.1 in.
This is a schematic diagram illustrating the
many details of the CBR test. This
“index” test is not very popular anymore.
2-5.15
Instructor’s Guide
Module 2-5. Field Sampling and Testing
Slide
25
Indirect Tension Test
 a.k.a.: Splitting tension or split tensile test
 Used to determine the tensile strength
and/or Mr of any bound material
 100 or 150 mm diameter (D)
specimens
 Sample length should be
at least half the diameter
D
Load, P
v
r
 Prepared samples or cores
Length
 The indirect tension test is also known
by other names.
 PCC specimens are typically loaded to
failure to determine the tensile strength.
LVDTs can be attached, however, to
determine the resilient modulus of the
material.
 Test can be performed on either of the
two typical specimen sizes, however,
the length should be at least half the
diameter.
 Test can be run on either prepared
samples or cores.
 Conversions: 100 mm = 4 in; 150 mm
= 6 in.
This diagram illustrates the way in which
cylindrical specimens are loaded to
indirectly generate tension. A compressive
load is applied through loading strips at the
top and bottom of the sample.
Slide
26
Evaluating Pavement Layers
Subgrade Soils
 Soil classification (Unified or AASHTO)
 Moisture content and density
 DCP
 Resilient modulus:
Slide
27

Measure in the lab

Backcalculate from NDT data

Estimated from correlation with Rvalue, CBR, or other soil properties
Evaluating Pavement Layers
Unbound Base & Subbase Layers
 Visual inspection

Layer thickness

Degradation or contamination by fines
 DCP
 Density and moisture content
 Resilient modulus
2-5.16
This slide indicates the suggested tests on
samples of the subgrade soil.
 Although they do not typically serve as
direct inputs to the rehabilitation design
process, soil class, moisture content,
density and DCP values do provide the
engineer/designer with supportive
information on the quality of the soil.
 Resilient modulus, on the other hand,
does represent a key input to
determining the structural capacity of
the existing pavement as well as the
thickness of any planned overlays.
This slide indicates the candidate field and
lab tests for the base and subbase layers.
 The visual inspection of the base and
subbase layers confirms their thickness
and provides a good indication of their
structural integrity.
 The DCP, density and moisture content
provide the designer/engineer with an
indication of the stiffness and overall
quality of the unbound layers.
 Resilient modulus is a key input to
determining the structural capacity of
the existing pavement as well as the
thickness of any anticipated overlays.
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Module 2-5. Field Sampling and Testing
Point out that resilient modulus can be
lab measured, backcalculated, or
correlated with other tests.
Slide
28
Evaluating Pavement Layers
HMA Surface and Stabilized Base Layers
 Visual inspection of cores

Layer thickness

Stripping, segregation, erosion
 Asphalt content and gradation
 Resilient modulus
Slide
29

Lab measured (indirect tension)

Backcalculated
Other Considerations
 Volume stability
 Stripping
 Seasonal variations in moisture
 Permeability
HMA Pavement Evaluation and Rehabilitation
Shown here are alternative tests for the
HMA surface and stabilized base layers.
 The visual inspection of the cores
confirms thicknesses of the HMA and
stabilized base layers. It also provides
an opportunity to determine if the
layers are experiencing any
deterioration in the form of stripping,
segregation or erosion.
 Asphalt content and gradation are
usually only required if a rehabilitation
alternative involving mix recycling is
involved.
 As was the case with the subgrade soil
and granular layers, resilient modulus is
a key input to determining the
structural capacity of the existing
pavement as well as the thickness of
any anticipated overlays.
Other rehabilitation design considerations
include:
1. Volume stability – This refers to the
swelling potential for the subgrade soil
(not usually a big problem after the
original pavement has been there for a
while) and the potential for thermal
contraction and expansion in the HMA
layer (reflection cracking issue).
2. Stripping – This is a form of HMA
pavement deterioration that is difficult
to detect without coring. Its existence
can have a major impact on the
structural capacity of the existing
pavement and the selection of
appropriate rehabilitation treatments.
3. Seasonal variations in moisture –
Recognize that the conditions during
which the pavement is sampled and
tested may not be representative of the
average conditions throughout the year.
In environments where moisture
contents vary significantly,
consideration should be given to
quantifying the variability and
accounting for it in the rehabilitation
design process.
2-5.17
Module 2-5. Field Sampling and Testing
Instructor’s Guide
4. Permeability – In pavements where
excess moisture is a problem and
drainage is an issue, it may be
worthwhile conducting permeability
tests on the existing subsurface
materials. This could help determine
whether added drainage features as part
of the rehabilitation design are worth
considering. (Edge drains and base
day-lighting are examples of these
candidate drainage improvement
options).
Slide
30
Use of Field and Lab Tests
in Rehabilitation Design
 Help characterize existing support and
quantify effect of deterioration
 Field and lab testing vary depending on:
Slide
31

Material type (i.e., subgrade soil,
unbound base or subbase, and HMA
surface or stabilized base)

Candidate types of rehabilitation
treatments (for example, recycling
justifies a higher level of lab testing)
Review
 What are two situations where field
sampling and lab testing may be
required?
 What kind of sampling and testing would
you now consider?
 What is the motivation for resilient
modulus testing?
 Name two ways in which field/lab test
results can be used in rehab design?
2-5.18
1. Data gathered from field and laboratory
testing complement the data gathered as
part of the condition surveys and the
NDT program. Together, they provide
a basis for characterizing the support
offered by the existing pavement to a
subsequent overlay and to quantify the
effect of past deterioration.
2. Field and laboratory testing
requirements vary depending upon the
materials that make up the pavement
structure and the candidate types of
rehabilitation treatments.
Upon completing this module, the
instructor should review these questions
with the participants to reinforce their
learning.
HMA Pavement Evaluation and Rehabilitation
Instructor’s Guide
Slide
32
Module 2-5. Field Sampling and Testing
Key References
 Washington State Department of
Transportation (WSDOT). 1995.
WSDOT Pavement Design Guide.
Washington State Department of
Transportation, Olympia, WA.
 Livneh, M. 1987. “The Use of Dynamic
Cone Penetrometer in Determining the
Strength of Existing Pavements and
Subgrades.” Proceedings, 9th Southeast
Asian Geotechnical Conference.
Bangkok, Thailand.
HMA Pavement Evaluation and Rehabilitation
Shown here are some other key references
for information on field sampling and
testing.
2-5.19
Instructor’s Guide
Module 2-5. Field Sampling and Testing
NOTES
2-5.20
HMA Pavement Evaluation and Rehabilitation