For SHRP document purchase instructions, visit the TRB Bookstore.
Asphalt: A Strategic Plan--1990
Discusses the objectives and planned products of the asphalt
program area as of 1990, including performance-based specifications for asphalt binders and
asphalt-aggregate mixtures. Describes numerous secondary research products. 56 pages.
Summary Report on the Aging of Asphalt-Aggregate Systems
A literature study of the aging phenomenon in asphalt-
aggregate mixtures. This report identifies aging procedures that show promise for development
as performance-related accelerated aging tests. 100 pages.
Summary Report on Low Temperature and Thermal Fatigue Cracking
Presents the results of a literature review and analyzes responses to a survey questionnaire
sent to state departments of transportation. Eight performance-related test systems and methods
are evaluated. 83 pages.
Hypotheses and Models Employed in the SHRP Asphalt Research Program
Updates the information presented in Asphalt: A Strategic
Plan-1990. 64 pages.
Summary Report on Fatigue Response of Asphalt Mixtures
Researchers evaluated current test methods and procedures for measuring the fatigue response
of asphalt paving mixtures. Factors influencing fatigue response, including specimen fabrication,
mode of loading, mixture variables, and loading and environmental variables are also discussed.
A Literature Review of the Adsorption of Asphalt Functionalities on Aggregate Surfaces
Examines the current state of knowledge of the theoretical and technical aspects of adsorption
and how adsorption of polar functionalities influences the chemistry of the asphalt-aggregate
interface. 34 pages.
Asphalt Properties and Relationship to Pavement Performance: Literature Review
A summary and analysis of information in technical literature that relates chemical and physical
asphalt properties to pavement performance. 413 pages.
Summary Report on Permanent Deformation in
Examines information concerning permanent deformation characteristics of asphalt-aggregate
mixtures. 120 pages.
Binder Characterization and Evaluation by
Nuclear MagneticResonance Spectroscopy
Eight asphalt cements were studied in solution-state and solid-state experiments to obtain
information about: the amounts of aromatic carbon in an average asphalt molecule; how carbon is
arranged in terms of the size of the aromatic system and the extent of substitution; arrangement and
number of alicyclic rings, aliphatic chain length, and the extent of branching. All these data and
more show both surprising similarities and significant differences among the asphalts studied. 1
Fundamental Properties of Asphalt-Aggregate
Interactions Including Adhesion and Absorption
The results of research on the chemistry and physics of the asphalt-aggregate bond include:
models of adhesion and stripping; a net adsorption test for a quick and reliable method to measure both the affinity and water sensitivity of a given asphalt-aggregate pair; and tests addressing specific problems involving asphalt-aggregate interactions such as the limestone reactivity test. Includes studies of
the impact of water and aging on adhesion. 605 pages.
Development and Validation of Performance
Prediction Models and Specifications for Asphalt Binders and Paving Mixes
Researchers developed a model to predict the amount of fatigue cracking, thermal cracking, and
rutting in asphalt concrete pavements over time, using results from the accelerated laboratory
tests. The model uses detailed environmental data and can determine the optimal mixture design
for specific conditions. The pavement performance models for each distress also were used to
confirm the relevant binder and mixture properties established by other SHRP contractors using
accelerated laboratory tests and laboratory torture tests; and to establish the degree of correlation
between those asphalt binder and mixture properties. Results from these model studies were used
to confirm or make recommendations for revisions to the asphalt binder specification. 518 pages.
Binder Characterization and Evaluation--Volume 1
Investigates the chemical and physical properties of petroleum asphalts used in the construction
of highway pavements. The chemical studies' objective was to measure and understand the interactions
among molecular species that contribute to behavior associated with high molecular weights, which
explains the rheological behavior of asphalt. The characterization of rheological behavior was
emphasized in the measurement of physical properties. A self-consistent description of petroleum
asphalt has been used to develop predictions of asphalt performance in pavements. The model and
predictive capability constitute the major portion of Volume 1. 152 pages.
Binder Characterization and
Evaluation--Volume 2: Chemistry
Describes the experimental results from the chemical composition studies. Analytical methods
such as streamlined preparative size exclusion chromatography, supercritical fluid chromatography,
and potentiometric titration were adapted for asphalt component analysis. As a result of these
separations, asphalt rheological properties were rationalized by chemical parameters such as
molecular weight, molecular size distribution, and polarity factors. Asphalt oxidation studies
indicate that the oxidative aging at service temperatures does not follow the classical radical-chain.
Binder Characterization and
Evaluation--Volume 3: Physical Characterization
Presents new test methods and models for test procedures for aging and adhesion of asphalt.
Stiffness of asphalt binders is characterized as a function of loading time and temperature.
The dynamic shear rheometer is used to characterize conditions at intermediate to upper pavement
surface temperatures. The newly developed bending beam rheometer is used to characterize
conditions at low temperatures, where thermal cracking is important. The direct tension test was
developed to characterize fracture properties. A new phenomenon, low-temperature physical
hardening, was identified. This phenomenon results in increased stiffness of the binder when held
at a constant temperature at room temperature or below. This report describes a new aging procedure
for simulating in-service oxidative hardening of asphalt binders. 475 pages.
Binder Characterization and
Evaluation--Volume 4: Test Methods
Describes the development of test methods for the characterization of asphalt cement. The
information was used to develop models that relate the properties of asphalt cement to mixture
properties and, in turn, to pavement performance. A method for the extraction and recovery of
asphalt binder from asphalt mixes is also included. 193 pages.
Superpave Manual of Specifications,
Test Methods and Practices
Documents the Superpave mix design system for new construction and overlays. This system employs
a series of new performance-based specifications, test methods and practices for material selection,
accelerated performance testing, and mix design. Specifications and procedure formats are suitable
for eventual standardization by the American Association of State Highway and Transportation Officials.
The Application of Small Nuclear Magnetic
Resonance Spectrometers to Quality Control Measurements of Asphalt and Asphalt-Aggregate Mixes
Illustrates the classic wide-line nuclear magnetic resonance techniques used to measure the
quantitative amounts of asphalt in asphalt-aggregate mixtures, including full 4-inch highway
cores. A method for correlating related physical property measurements to nuclear magnetic
resonance parameters is given for a wide range of neat asphalts. It is also shown how interactions
between the asphalt and the aggregate in a mixture influence the physical properties of the asphalt
and determine the physical properties of the mix. 42 pages.
Selection of Laboratory Aging Procedures for
Presents results of a preliminary investigation to evaluate short- and long-term aging methods for
asphalt-aggregate mixtures. Test specimens were fabricated to represent extreme property levels.
The four mixture combinations were prepared at two levels of permeability, representing good and
moderate compaction conditions. The effects of aging were determined using the diametral resilient
modulus test. 91 pages.
Aging: Binder Validation
One short-term and four long-term aging methods were used to simulate aging of asphalt-aggregate
mixtures in the field. Four aggregates and eight asphalts for a total of 32 different material
combinations were tested using the different aging methods. Results of the aging studies were
compared with the studies of asphalt binder and of asphalt mixed with fine aggregates. 81 pages.
Stiffness of Asphalt-Aggregate Mixes
Presents the evaluation of test systems for stiffness determination of asphalt-aggregate mixes,
including 1) axial resilient stiffness, 2) diametral resilient stiffness, 3) resilient and dynamic
flexural stiffness, and 4) dynamic shear stiffness. All tests were found to be sensitive to mix
and test variables. Temperature had the greatest effect on axial, diametral, and flexural stiffness.
Laboratory Aging of Asphalt-Aggregate Mixtures:
Describes two test procedures that simulate short- and long-term field aging of asphalt-aggregate
mixtures using oven aging technology. Analysis of field sites is used to develop prediction models
for all combinations of climatic region and asphalt grade. 204 pages.
Field Validation of the Environmental
Evaluates the environmental conditioning system and its ability to differentiate among asphalt
concrete mixtures performance in regard to water sensitivity in the field. Twelve test sections
were identified within four environmental regions. Specimens were also tested using two other
asphalt wheel trackers. 194 pages.
Stage 1 Validation of the Relationship Between
Asphalt Properties and Asphalt-Aggregate Mix Performance
Various test methods and conditioning procedures were evaluated for their ability to produce
specimens to predict asphalt-aggregate mix performance in terms of fatigue, permanent deformation,
and thermal cracking. These specimens sought to represent post-construction pavement after
short-term and long-term aging. Various combinations of asphalts and aggregates were subjected
to a wheel-tracking device, thermal stress restrained specimen test, oven aging and water-sensitivity
tests. 235 pages.
Low-Temperature Cracking: Binder Validation
Tests were performed on both short-term and long-term aged specimens to (1) relate fundamental
properties of asphalt cement and aggregate to the thermal cracking resistance of asphalt concrete
mixtures, and (2) validate a hypothesis for low-temperature cracking developed for SHRP by Western
Research Institute. Statistical analyses performed on the test results found that the results
correlated well with those found previously. 106 pages.
Low-Temperature Cracking: Test Selection
Describes the selection of the thermal stress restrained specimen test to evaluate low temperature cracking
resistance of asphalt concrete mixtures. The test is conducted by cooling an asphalt concrete specimen at a
specified rate while maintaining the specimen at a constant length. Four asphalts and two aggregates were
tested. 106 pages.
Low-Temperature Cracking: Field Validation of the Thermal
Stress Restrained Specimen Test
Evaluates the validity of the thermal stress restrained specimen test as an accelerated performance test to
predict low-temperature cracking of asphalt concrete mixtures. Included are construction histories, cracking
observations, and temperature data collected from five test roads. 116 pages.
Water Sensitivity: Binder Validation
The influence of binder properties on the moisture susceptibility of asphalt-aggregate mixes was evaluated
by using thirty-two mixes with a combination of eight asphalts and four aggregates. Four procedures were
used to test the mixes. 1) Environmental Conditioning System, 2) Oregon State University Wheel Tracker, 3) SWK
Pavement Engineering/University of Nottingham Wheel Tracker, and 4) Net Adsorption Test. Because the testing
procedures differed, it was not appropriate to make direct comparisons of the results. 104 pages.
Water Sensitivity of Asphalt-Aggregate Mixes:
This report describes the identification of the factors that influence water sensitivity of asphalt
paving mixtures and the development of a test method to evaluate water sensitivity of asphalt concrete
mixtures for mix design. The method was to be related to performance; no single current method was
suitable. A test system was developed to evaluate the major factors that influence water sensitivity. 183 pages.
Fatigue Response of Asphalt-Aggregate Mixes
Covers the development of accelerated performance tests for defining the fatigue response of asphalt-aggregate
mixes and their use in mix analysis and design systems. The report includes: a state-of-knowledge review for
fatigue response of asphalt-aggregate mixes; a description of two pilot test programs developed to validate
candidate tests, to provide an expanded database, and to develop models of fatigue behavior that might substitute
for laboratory testing; and a description of a mix analysis and design system to be used to mitigate fatigue
cracking. 309 pages.
The Superpave Mix Design Manual for New Construction and
Represents the Superpave mix design system in a complete step-by-step format intended for engineers and
technicians in public and private organizations to use when designing paving mixes for all classes of
highways, from farm-to- market roads to urban freeways. 172 pages.
Level One Mix Design: Materials Selection, Compaction,
Conditioning A summary of the research of three aspects of the Superpave
Level 1 mix design: volumetric mix design criteria for aggregates and mixes; compaction; and mix
conditioning. A Delphi group process was used to select aggregate properties and specification
values to be included in the Level 1 mix design procedure. Chapter 2 addresses the rationale for
the selection of the gyratory compactor, its relation to field control, and validation. The final
chapter summarizes the research associated with the development and validation of laboratory conditioning
procedures for asphalt concrete mixes. It describes the procedures used to simulate both long-
and short-term aging, as well as moisture sensitivity under repeated loading. 121 pages.
Validation of Relationships Between Specification
Properties and Performance
A summary of the two-stage validation of the proposed binder and mix specifications and tests. Stage 1
addresses the validation of the specifications and tests with laboratory data; Stage 2, with field
performance data. The report is divided into four chapters. The first chapter outlines the validation
process. Chapters 2 and 3 describe the Stage 1 and 2 validation, respectively, and include a comprehensive
discussion of the laboratory testing undertaken to evaluate asphalt concrete performance in terms of
permanent deformation, fatigue cracking, and low-temperature cracking. Chapter 4 addresses the validation
testing conducted using modified materials.
Superior Performing Asphalt Pavements (Superpave):
The Product of the SHRP Asphalt Research Program
This report describes the Superpave mix design system and the various parts that compose its
operational characteristics. This report provides background for readers who want a more detailed
description of the methodology, test methods, and theory behind Superpave than that provided in
Superpave: Superior Performing Asphalt Pavements (SHRP-A-411). 156 pages.
Permanent Deformation Response of Asphalt-Aggregate
This report describes SHRP's research conducted on permanent deformation of asphalt concrete mixes.
The report is presented in three sections: one on the development of a series of accelerated
performance tests to measure the permanent deformation response and a constitutive relationship
to define it; validation of the binder properties included in the SHRP binder specification; and
the use of the test methodology in an asphalt concrete mix
design and analysis system. 438 pages.
Accelerated Performance-Related Tests for Asphalt-Aggregate
Mixes and Their Use in Mix Design and Analysis Systems
A summary of the processes that led to the selection of the SHRP tests for fatigue, permanent deformation,
thermal cracking, aging, and water sensitivity. Inherent in this test selection process was the emphasis
on the ability of the tests to measure fundamental material properties that, when incorporated into
prediction models, will depend less on empirical correlations than has traditionally been the case.
Also included are the results of validation studies for each of the tests and frameworks for the use
of the tests in mix design and analysis. Several levels of design are provided for each distress,
some of which incorporate reliability concepts.
The SHRP Asphalt Research Program: 1990 Strategic
Describes SHRP's asphalt research program, emphasizing goal definition and program structure.
It illustrates available methods of data analysis, in particular the free-form, intuitive approach
used for interpretation and synthesis to achieve specific products when rigorous mathematical
methods are ineffective. Presents restructuring options for increased effectiveness in attaining
goals with set time and budget constraints. 96 pages.
Absorption of Asphalt into Porous Aggregates
Examines current knowledge concerning how aggregate properties influence absorption and how absorption
can best be determined for practical use. Discusses methods for recovery of unabsorbed asphalt to
ascertain the extent and importance of selective absorption, and methods to minimize the adverse
effects of absorption on pavement performance. 33 pages.
A Literature Review of Liquid Antistripping Agents,
Mineral Additives, and Tests for Measuring Stripping
Focuses upon the chemistry of liquid amino base antistripping agents and mineral agents, and their
contribution to adhesion and resistance of the asphalt- aggregate bond from the intrusion of water.
Tests performed to evaluate these agents are also reviewed. (See also Summary Report on Water
Sensitivity, SHRP-A-304.) 19 pages.
HP-GPC and Asphalt Characterization
Describes the use of High Pressure Gel Permeation Chromatography to characterize asphalt
properties and the relationship of these parameters to pavement performance. 140 pages.
The Effect of the Physical and Chemical Characteristics
of the Aggregate on Bonding
Reviews literature pertaining to physical and chemical characteristics of aggregates that
have a significant effect on the bonding between aggregate and the asphalt. Research
focused on the role played by morphology, electrical properties, and the mineral
composition of the aggregate in its interaction with water. The report also examines
the chemical functionalities in both asphalt and aggregates that play a predominant
role in bonding, as well as the effect of surface modification of the aggregate and
the use of antistripping agents. 23 pages.
Factors Influencing Mix Setting Characteristics
and Tests to Predict Mix Setting Characteristics
Reviews the available literature pertaining to the various asphalt and aggregate properties
that influence the setting characteristics of the mix. The report also identifies the
various tests used to measure such mix characteristics. 13 pages.
The SHRP Materials Reference Library
Aggregates: Chemical, Mineralogical, and Sorption Analyses
Summarizes the data for aggregates (two limestones, two granites, one basalt, one calcareous
sandstone, one greywacke, and four gravels) collected as reference materials. These
aggregates represent a geographically and lithologically diverse group of materials
spanning the more commonly utilized bituminous aggregates. 88 pages.
Chemical Properties of Asphalts and Their
Relationships to Pavement Performance
Describes the current status of the SHRP chemical studies of petroleum asphalt. The report
attempts to correlate some of the known chemical properties of asphalt with pavement performance
characteristics. 30 pages.
Prediction of Fatigue Cracking and Rutting in
Asphalt Pavements by Small-Scale Centrifuge Models
Centrifuge modeling was investigated to determine its feasibility for the prediction of fatigue
cracking and rutting in full-depth asphalt pavements. A small-scale model of a pavement
section was constructed and subjected to repeated loading tests in a centrifuge. Resilient
tensile strains were measured at the bottom of the asphalt layer and the accumulated permanent
deformations near the pavement surface. The models were tested to 10,000 repetitions,
but more than one million repetitions may be required to induce fatigue cracking. A static
load test also was performed after the repeated load test. 82 pages.
Preliminary Analysis of BPR Data
Describes a preliminary analysis of asphalt cement samples collected by the Bureau of Public
Roads (BPR) from 1954 to 1956. Samples from 210 construction projects in 26 states were
collected. No trends or simple correlations were found between the pavement performance
variables measured and the asphalt binder and mix properties selected for this analysis. 57 pages.
Experimental Design Guidelines for Asphalt
Research Contractors, Revised 1991
Examines the objectives of the asphalt research
program and the role of experimental designs; the need for application of experimental designs;
the selection of materials for the materials reference library; the asphalt program database;
and the application of experimental design concepts to the development of an asphalt mix design
system. 35 pages.
Evaluation of Laboratory Procedures for
Compacting Asphalt-Aggregate Mixtures
Examines three compaction methods: Texas
gyratory, kneading, and rolling wheel compaction. Unlike static and impact compactors, these
compactors subject the densifying mixture to shearing motions similar to those induced during
field compaction. Differences among the compaction methods are greatest for mixtures with
low air voids, presumably because pore pressures are larger when there are fewer air voids in
the mixture. Depending on their design and operation, compactors within a given genre may
produce specimens having quite different engineering properties. 265 pages.
Validation in the SHRP Asphalt Research
Program (October 1991)
Development of performance-based specifications requires validation of those properties
identified as important determinants of pavement performance. This report describes the
first two stages of the three-stage validation process to be completed through SHRP's research
program, and the third stage, to be performed by the long-term pavement performance program. 40 pages.
The Use of Conversion Residue as a
Component in Asphalt Cement
Describes why conversion residue, as a blending component in heavy fuel oils or as a
refinery fuel, provides superior resistance to moisture-induced damage and similar
hardening characteristics of conventional asphalt when blended into paving grade asphalt. 105 pages.
Development of a Technique for In Situ Measurement
of Water at the Asphalt/Model Siliceous Aggregate Interface
Describes the development of a method for measuring water in situ at the interface between an
asphalt and a model siliceous aggregate. Based on Fourier transform infrared spectroscopy in
the multiple internal reflection mode, the technique is useful for evaluating asphalt/siliceous
model aggregate mixtures in terms of 1) water susceptibility of an asphalt/aggregate mixtures, 2)
effectiveness of antistripping agents, 3) effects of aggregate surface contamination and
environmental temperature on water stripping, and 4) water diffusion through asphalts on an aggregate.
Test results for measuring the bond strength of an asphalt on an aggregate in the presence of water
are given. 56 pages.
A Differential Scanning Calorimetry Study
of Asphalt Binders
Examines the use of differential scanning calorimetry for studying the thermal properties
and behaviors of asphalt. This technique provides parameters for comparing the glass
transition temperatures; endothermic behavior of asphalt fractions and whole asphalts;
aging; and slow cooling and heat rate effects of eight SHRP core asphalts and several
other asphalts. 43 pages.
Review of State and Industry Reports on
Asphalt Properties and Relationship to Pavement Performance
Reviews results of ten studies on the relationship between asphalt binder and mix properties,
both physical and chemical, and the field performance of pavements. Four areas of pavement
performance were measured: stripping, low temperature transverse cracking, rutting and bleeding.
(See also Asphalt Properties and Relationships to Pavement Performance: Literature Review, SHRP-A-314.) 161 pages.
Bibliographies for Physical Properties
of Asphalt Cement
Contains 497 records complied from the Compendex Plus and the National Technical Information
Service databases. Included are studies from technical journals, books, conference proceedings,
and research reports relevant to the properties of asphaltic materials and their performance.
The bibliography has five sections: durability; characterizations; thermal cracking; moisture
damage; and fracture, fatigue, and rutting. 530 pages.
Advanced High Performance Gel Permeation
Explores the use of high performance gel permeation chromatography as a means of studying
asphalt composition and intermolecular interaction. SHRP core asphalts, their acid-base
fractions, and laboratory-oxidized counterparts were analyzed. Based on the concept that
molecular size distribution and the molecules' ability to assemble into larger entities in
solution and into networks in neat asphalt are crucial to the performance of the asphalt.
Attributes of the network formed will determine the asphalt's ability to resist thermal shock,
for example, by providing strength and elasticity. 122 pages.
Review of Relationships between Modified
Asphalt Properties and Pavement Performance
The scope of this literature review was to collect and summarize information in the
technical literature relating modified asphalt properties to field pavement performance;
to report the original findings and conclusions of the authors; and to note any trends or
consensus. The resources reviewed included published literature, state highway agency
research reports, inquiries to associations and manufacturers, and a search of the
National Technical Information Services' database. One conclusion is that (a) asphalt
modifiers do influence binder and mixture properties and hence performance; and (b) the
ability to accurately interpret the association between asphalt modifiers and pavement
performance has not been established through field studies. 228 pages.
SHRP Archival Database B User's Manual Version 2.0
Contains instructions for the use of the SHRP Asphalt Research Program Archival Database.
The report provides detailed, step-by-step instructions for retrieving, viewing, searching,
and downloading of the files contained in the database. 72 pages.
Analysis of the Integrated Model of
Climatic Effects on Pavements
The Federal Highway Administration showed that simulations of climatic effects on pavement
temperature are capable of estimating pavement temperature when realistic input variables are
used. An analysis also evaluated the influence of air temperature, solar radiation, percent
sunshine, and thermal properties on calculated pavement temperatures. 158 pages.
Archival Database Specifications for the
SHRP Asphalt Research Program
Contains information about the development of text and data files for the SHRP asphalt
research program database. All files developed by the asphalt research program contractors
followed the format set forth in this document. 37 pages.
Direct Tension Test Experiments
Documents the results from the Asphalt Institute, which led to the elimination of the direct
tension test from the suite of SHRP performance tests for asphalt mixture specifications. 40 pages.
SHRP Materials Reference Library:
Asphalt Cements: A Concise Data Compilation
Presents a compilation of the chemical and physical properties of the asphalt cements
contained in the SHRP Materials Reference Library. 27 pages.
The SHRP Materials Reference Library
Contains information on materials collected and stored at the SHRP Materials Reference
Library and used by the asphalt research program contractors and other SHRP researchers.
Describes the materials and how they were selected, their properties, procurement, storage,
and processing. 231 pages.
Weather Database for the Superpave Mix Design System
Contains a database of 5,313 United States and 1,515 Canadian weather stations, which
can be used to select a suitable performance grade of asphalt binder for a paving project,
based on prevailing weather conditions in the area. This report briefly describes how
the Superpave software functions and presents selected contents of the weather database
in tabular form. 119 pages.
Fluorometric Characterization of Asphalts
Discusses the development of fluorescence microphotometry measurements of fluorescence intensity
and spectra to characterize asphalts. Results demonstrate that fluorometric measurement of
asphalt intensity has potential for monitoring asphalt oxidation occurring at the hot-mix and
lay-down stages of asphalt production, as well as monitoring deterioration of in-service asphalt
pavements. 85 pages.
Summary of Health Practices: The Use of
Petroleum Asphalt in the Hot-Mix Paving Industry
Reviews the literature regarding aspects of human health and the environment as related
to the use of asphalt cements in the paving industry. The report cites exposure studies;
clinical and epidemiological reports; animal toxicological studies; and discussions on
polynuclear aromatic hydrocarbons in paving asphalts and asphalt emissions. 156 pages.
Development of an Asphalt Core Tomographer
A standard imaging procedure was used to develop a protocol to determine asphalt mass
fractions in mixed or coarse aggregate cores. The protocol generates estimates of true mass
fractions inside the core and can be used to study the three-dimensional internal deformations
that occur as a core goes through different loading cycles. 101 pages.
Size Exclusion Chromatography and Ion
Exchange Chromatography Separations of Asphalt
Describes experimental procedures
used in the separation of asphalts by size exclusion chromatography and ion exchange chromatography.
These experimental procedures were developed during the course of SHRP's binder characterization
and evaluation program. A brief background section on chromatographic separations of asphalts is included.
Analysis of Sulfur Compound Types in Asphalt
Outlines the evaluation of methods for determining sulfur compound types in asphalts from the SHRP
Materials Reference Library. Methods used included infrared, tetrabutylammoniumperiodate oxidation,
and oxidation with hydrogen peroxide. Whole asphalts and fractions were processed through liquid
chromatographic separations. Sulfur types present at negligible concentrations were thiols, sulfones,
and sulfonic acids. 46 pages.
The Characterization of Asphalt and Asphalt Recyclability
Describes the construction of a computer model to understand how asphalt components
mix with one another. 26 pages.
Application of Acoustic Emission to Study
the Cohesive and Adhesive Strength of Asphalt
Describes the development of a combined acoustic emission-poker chip test to measure the
mechanical behavior of, and cavitation in, asphalt thin films. Combining results of the
test with the appropriate stress analysis and fractography allows us to understand the
controlling fracture mechanism of geometrically confined asphalt thin films. The test
successfully differentiates different SHRP asphalts. The test provides a logical link
among asphalt bulk rheological properties, microstructure in asphalt thin films, and performance
properties of asphalt-aggregate mixtures. A laser contact angle goniometry technique and a
modified blister test were developed to characterize, respectively, the asphalt surfaces and
the adhesive strength between asphalt and aggregate surfaces. 273 pages.
Development of SHRP Asphalt Research
Program Climatic Databases
Describes the development of two climatic databases
for use in performance prediction models. The summary weather database includes a number
of statistical parameters on seven-day maximum air temperatures and lowest annual temperatures
for 6,000 weather stations in the United States and for 1,800 weather stations in Canada. 63 pages.
Guidelines for Asphalt Refiners and Suppliers
Describes various SHRP researchers' key findings, with emphasis on those fundamental chemical and physical
properties of the binder that relate to its susceptibility to various distresses. Consideration and
evaluation of the polar and non-polar molecules assists in understanding the performance of a given
asphalt. The polars largely dictate the ability of an asphalt to resist permanent deformation. Low
temperature cracking and fatigue cracking are largely influenced by the non-polar fraction. The
impact of aging and asphalt compatibility on these distress modes is also discussed. 98 pages.
Development and Use of the Repeated Shear
Test (Constant Height): An Optional Superpave Mix Design Test
This study investigated rut development in asphalt pavements to establish the foundations for
the prediction of rutting in pavement structures. This paper presents advances in the
characterization of asphalt-aggregate mixes by using finite element technology to predict
permanent deformation. Although fatigue and thermal cracking may affect permanent deformation,
such mechanisms are not discussed as they are considered of secondary importance. 94 pages.
Performance Prediction Models in the
Superpave Mix Design System
SHRP's asphalt research program developed performance-based asphalt binder and asphalt
paving mix specifications to control three distress modes: permanent deformation; fatigue
cracking; and low-temperature cracking. Detailed pavement performance models support
the development of these specifications. They are an integral tool for mix design in
the Superpave mix design system. This report summarizes the theoretical development,
structure, and features of these performance models. The models can minimize a specific
distress or combinations of different distresses, or they can set specification limits
for specific materials and environments. 88 pages.
Superpave Video Asphalt Pavements that
Benefits of performance-based asphalt specifications. February 1992. 5 minutes.
Tape No. 5