Journal Article•
Factors influencing the resilient response of granular materials
TL;DR: In this paper, a study of the resilience of a SANDY CLAY structure was conducted, where the authors defined a set of techniques that contribute to the robustness of the structure to load.
Abstract: THE PURPOSE IS TO DEFINE BETTER THOSE PROPERTIES OF GRANULAR BASE MATERIALS THAT CONTRIBUTE TO THE RESILIENT RESPONSE OF PAVEMENT STRUCTURES. A STUDY IS INCLUDED OF THE INFLUENCE OF AGGREGATE DENSITY, AGGREGATE GRADATION (PERCENT PASSING NO. 200 SIEVE), AND DEGREE OF SATURATION ON THE RESILIENT RESPONSE OF TWO AGGREGATES REPRESENTATIVE OF THOSE USED IN THE CONSTRUCTION OF ASPHALT CONCRETE PAVEMENTS. TESTS CARRIED OUT IN TRIAXIAL COMPRESSION, CONSISTED OF APPLYING REPEATED AXIAL STRESSES WITH REALISTIC STRESS HISTORIES AT A FIXED FREQUENCY AND AT A LOAD DURATION REPRESENTATIVE OF THAT EXPECTED IN THE FIELD. FOR BOTH GRANULAR MATERIALS, THE RESILIENT MODULUS INCREASED CONSIDERABLY WITH AN INCREASE IN CONFINING PRESSURE AND ONLY SLIGHTLY WITH AN INCREASE IN AXIAL STRESS. POISSON'S RATIO INCREASED WITH A DECREASE IN CONFINING PRESSURE AND AN INCREASE IN REPEATED STRESS. THE RESILIENT MODULUS AND POISSON'S RATIO WERE ALSO AFFECTED TO LESSER DEGREES BY DENSITY, PERCENT PASSING THE NO. 200 SIEVE, AND DEGREE OF SATURATION. AN ANALYSIS OF A CONVENTIONAL ASPHALT CONCRETE PAVEMENT OVER A SANDY CLAY SUBGRADE INDICATED THAT REASONABLE CHANGES IN THE MODULUS OR POISSON'S RATIO OF THE GRANULAR BASE LAYER CAN RESULT IN CONSIDERABLE CHANGES IN THE RESPONSE OF THE PAVEMENT STRUCTURE TO LOAD. /AUTHOR/
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01 Jan 2000
TL;DR: In this article, a state-of-the-art survey on resilient stress-strain characteristics of unbound aggregates is presented, and different views on the impact of each individual factor are discussed.
Abstract: The findings of an extensive literature survey on the structural response of unbound aggregates are discussed in two companion papers. In this paper, a state of the art is presented on resilient stress-strain characteristics of such materials, as well as different modeling techniques. The resilient response of aggregates is affected by several factors with varying degrees of importance. These are presented, and different views on the impact of each individual factor are discussed. Research efforts in the past have resulted in different math- ematical models for predicting the resilient response of aggregates under repeated traffic-type loading. The models found in the literature are listed, and their advantages and shortcomings are reviewed. The permanent strain characteristics of unbound aggregates are considered in a separate companion paper.
524 citations
Cites background or methods from "Factors influencing the resilient r..."
...This was used by Hicks and Monismith (1971), who approximated the variation of Poisson’s ratio with stresses by a third-degree polynomial expression given by 2 3 s s s1 1 1 n = A 1 B 1 C 1 D (11)r S D S D S Ds s s3 3 3 Karasahin (1993), who employed both constant and variable confinement in his…...
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...Hicks and Monismith (1971), on the other hand, reported a slight softening of the material at low deviator stress levels and a slight stiffening at higher stress levels....
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...Hicks and Monismith (1971) found the effect of density to be greater for partially crushed than for fully crushed aggregates....
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...However, studies (Hicks 1970; Hicks and Monismith 1971; Brown and Hyde 1975; Boyce 1980; Sweere 1990; Kolisoja 1997) have shown that Poisson’s ratio is not a constant and varies with applied stresses....
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...However, many researchers (Hicks 1970; Hicks and Monismith 1971; Allen 1973; Allen and Thompson 1974; Thom 1988; Barksdale and Itani 1989; Thom and Brown 1989) have reported that crushed aggregate, having angular to subangular shaped particles, provides better load spreading properties and a higher…...
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TL;DR: In this paper, the authors apply the principles of soil mechanics to the design of pavement foundations, and apply this knowledge to pavement design with the aid of appropriate theoretical analysis and an understanding of failure mechanisms.
Abstract: Application of soil mechanics principles to the design of pavement foundations, the design of complete pavements and to their structural evaluation'in-service' has lagged some way behind knowledge accumulated through research. Present design methods are generally empirical and often based on use of the California Bearing Ratio test, which was abandoned in California some fifty years ago. The soil mechanics problem is one of understanding how soils and granular materials respond to repeated loading and applying this knowledge to pavement design with the aid of appropriate theoretical analysis and an understanding of failure mechanisms. Non-linear stress-strain characteristics are a particular feature of the problem and have to be catered for in design and evaluation. Various ‘tools’ are available to assist the pavement engineer. These include theoretical analysis, laboratory testing apparatus, field testing and full-scale trials with appropriate instrumentation. The resilient and permanent strain response ...
321 citations
01 Feb 1990
TL;DR: In this paper, the authors evaluate test procedures for measuring the fatigue response of asphalt paving mixtures, and summarizes current knowledge of the factors that influence fatigue response, including material fabrication, mode of loading, mixture variables, and loading and environmental variables.
Abstract: This report evaluates test procedures for measuring the fatigue response of asphalt paving mixtures, and summarizes current knowledge of the factors that influence fatigue response. Available test methods are classified, and criteria used to evaluate each method for its potential use as a laboratory standard are discussed. The 3 most promising methods are considered to be simple flexure, diametral fatigue, and tests based on fracture mechanics principles. Factors affecting fatigue repsonse include specimen fabrication, mode of laoding, mixture variables, and loading and environmental variables. Mode of loading, typically either controlled-stress or controlled-strain for laboratory testing, is one of the primary factors affecting fatigue response. Air void content and temperature, both affecting mixture stiffness, may have more significant influence on fatigue repsonse than any other variable. Many mixture, load, and environmental factors also influence fatigue respose and must be considered both in the development of test protocols and in the determination of asphalt and mixture properties that are essential for fatigue-resistant pavements.
128 citations
TL;DR: In this article, a procedure is described to relate the soil-index properties and the moduli obtained from unconfined compression tests, to resilient modulus, and two statistical models are described and demonstrated for 11 soils from throughout the state of Tennessee.
Abstract: Mechanistic pavement design procedures based on elastic layer theory require the specification of elastic moduli for each material in the pavement section. Repeated load tests yielding a resilient modulus are frequently used to characterize the soil subgrade. Due to difficulties associated with cyclic testing, approximate methods are often used for design estimates of resilient modulus. These approximations are often based only on shear strength measures and do not account for the dependence on the magnitude of cyclic deviator stress. A procedure is described to relate the soil-index properties and the moduli obtained from unconfined compression tests, to resilient modulus. Two statistical models are described and demonstrated for 11 soils from throughout the state of Tennessee. One model provides an estimation of the breakpoint resilient modulus, or the modulus at a deviator stress of 6 psi (41 kPa). The second model provides a general nonlinear relationship for the modulus of fine-grained soils as a function of deviator stress. Both models are demonstrated for a range of soils and are shown to provide a good characterization of the response for the soils investigated. Similar relationships can be developed for other subgrade soils, and may prove useful to agencies that use deterministic pavement design procedures, but lack the capability for high-production repeated-load testing.
128 citations
01 Aug 2008
TL;DR: The Austroads publication Guide to Pavement Technology, Part 2: Pavement Structural Design is intended to assist those required to plan and design new pavements as discussed by the authors, it was originally produced in 1987 as a result of review of the NAASRA Interim Guide to pavement Thickness Design (1979).
Abstract: The Austroads publication Guide to Pavement Technology, Part 2: Pavement Structural Design is intended to assist those required to plan and design new pavements. It was originally produced in 1987 as a result of review of the NAASRA Interim Guide to Pavement Thickness Design (1979). In 1992, the Austroads Pavement Design Guide was revised to include an updated procedure for the design of rigid pavements and also relevant portions of Chapter 6 (Pavement Materials) and Chapter 7 (Design Traffic). An essential element in the use of the Guide is a thorough understanding of the origins of the design procedures, their scope and limitations. Accordingly, this report contains the following five technical reports detailing the technical basis of: 1. Chapter 1: 1992 Guide procedures for the design of flexible pavements; 2. Chapter 2: 1992 Guide procedures for design of rigid pavements; 3. Chapter 3: Guide to Pavement Technology Part 2 Design of flexible pavements; 4. Chapter 4: Guide to Pavement Technology Part 2 Design of rigid pavements; 5. Chapter 5: Guide to Pavement Technology Part 2: Development of design charts for lightly trafficked roads
126 citations
References
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Journal Article•
TL;DR: In this paper, the authors present a review of existing information on the resilience of fine-grained soils, grasps, and bituminous surface couRSs.
Abstract: RESEARCH IS REPORTED WHICH CONSTITUTES SIGNIFICANT PROGRESS TOWARD THE UNDERSTANDING OF PAVEMENT BEHAVIOR WITH REGARD TO FATIGUE CRACKING OF BITUMINOUS SURFACES SUBJECTED TO MANY REPETITIONS OF HEAVY LOADS. A THOROUGH REVIEW IS PRESENTED OF EXISTING INFORMATION ON THE RESILIENT CHARACTERISTICS OF FINE-GRAINED SUBGRADE SOILS, GRANULAR BASED MATERIALS, AND BITUMINOUS SURFACE COURSES. SUGGESTED METHODS FOR PREDICTING DEFLECTIONS OF BITUMINOUS PAVEMENTS FROM LABORATORY REPEATED-LOAD TESTS ARE DEVELOPED. TEST DATA FROM FIELD TESTS ON PROTOTYPE PAVEMENTS AND LABORATORY TESTS ON THE COMPONENTS OF THESE PAVEMENTS ARE USED TO DEMONSTRATE THE APPLICABILITY OF THE PROPOSED METHODS.
129 citations
01 Jan 1967
TL;DR: In this paper, the authors present results of studies on the mechanical properties of the materials constituting the various layers of an experimental asphalt base project constructed in Colorado, and the initial investigations reported in the paper are part of a continuing Asphalt Institute program of studies of asphalt bases and on the structural design of asphalt pavements.
Abstract: The paper presents results of studies on the mechanical properties of the materials constituting the various layers of an experimental asphalt base project constructed in Colorado. The initial investigations reported in the paper are part of a continuing Asphalt Institute program of studies of asphalt bases and on the structural design of asphalt pavements.
28 citations
01 Jan 1970
TL;DR: In this article, an attempt was made to determine the type of correlation that can be expected between the ORETICAL PREDICTIONS and OBSERVED MEASUREMENTS and, more important, to determine if the PREDictioned or measured response is correlated with OBSerVED PAVEMENT performance.
Abstract: THE STARTING POINT WAS THE OPINION THAT IF IT WERE POSSIBLE TO PREDICT BY MEANS OF THEORY THE PERTINENT STRESS, STRAIN, AND DEFLECTION RESPONSES DUE TO WHEEL LOADS, A VALUABLE STEP COULD BE TAKEN IN THE EFFICIENT DESIGN AND EVALUATION OF PAVEMENTS AND THE ECONOMICAL UTILIZATION OF PAVEMENT MATERIALS. AN EFFORT WAS MADE TO DETERMINE THE TYPE OF CORRELATIONS THAT CAN BE EXPECTED BETWEEN THEORETICAL PREDICTIONS AND OBSERVED MEASUREMENTS AND, MORE IMPORTANT, TO DETERMINE IF THE PREDICTED OR MEASURED RESPONSE CORRELATED WITH OBSERVED PAVEMENT PERFORMANCE. /AUTHOR/
10 citations
Journal Article•
TL;DR: A review of LABORATORY test data as mentioned in this paper reveals that most of the most common highway mediums, under conditions REPRESENTATIVE of moving traffic on an INSERVICE PAVEMENT, exhibit a non-linear response to stress.
Abstract: A REVIEW OF LABORATORY TEST DATA REVEALS THAT MOST COMMON HIGHWAY MATERIALS, UNDER CONDITIONS REPRESENTATIVE OF MOVING TRAFFIC ON AN INSERVICE PAVEMENT, EXHIBIT A NONLINEAR RESPONSE TO STRESS. THE REPORTED STRESS-STRAIN RESPONSE OF PAVEMENTS CONSTRUCTED WITH SUCH MATERIALS VARIES FROM THE STRESS-SOFTENING TO THE STRESS-STIFFENING TYPE, IN ACCORDANCE WITH THE RESPONSE OF THE CONSTITUTENT MATERIALS. A NONLINEAR ELASTIC INCREMENTAL FINITE ELEMENT ANALYSIS OF A UNIFORM SAND MASS SUBJECTED TO A UNIFORM CIRCULAR SURFACE LOAD , USING A CONSTITUTIVE EQUATION BASED ON PUBLISHED LABORATORY DATA, REVEALED A PRONOUNCED STIFFENING RELATIONSHIP BETWEEN THE APPLIED PRESSURE AND SURFACE DEFLECTION AND SLIGHTLY NONLINEAR RELATIONSHIPS BETWEEN THE APPLIED PRESSURE AND THE VERTICAL STRESSES INDUCED IN THE MASS. AN APPROXIMATE NONLINEAR ELASTIC ANALYSIS OF A FULL-DEPTH ASLPHAT CONCRETE PAVEMENT OVER A SANDY CLAY SUBGRADE, USING STRESS-STRAIN COEFFICIENT MATRICES MEASURED IN LABORATORY TRIAXIAL TESTS ON THE MATERIALS, GAVE ALMOST LINEAR RELATIONSHIPS BETWEEN THE APPLIED PRESSURE AND THE RESULTING DEFLECTION, AND DISTRIBUTIONS OF STRESSES AND STRAINS WITH THE STRUCTURE VERY SIMILAR TO THOSE YIELDED BY A LINEAR ELASTIC ANALYSIS USING STRESS-STRAIN COEFFICIENTS AT REALISTIC STRESS LEVELS. TO AN ENGINEERING APPROXIMATION, A LINEAR ANALYSIS WAS SUFFICIENTLY ACCURATE IN THE CASE OF THIS PARTICULAR FULL-DEPTH ASPHALT CONCRETE PAVEMENT BUT APPEARED UNACCEPTABLE IN THE CASE OF A PAVEMENT WITH UNBOUND GRANULAR MATERIALS CLOSE TO THE SURFACE. /AUTHOR/
8 citations
01 Jul 1966
TL;DR: In this paper, the authors developed a device that improves the convenience and authenticity of VOLUME CHANGE and pressure measurement by reversing the direction of movement of the EFFLUENT when the limit of the volume change scale is reached.
Abstract: A DEVICE HAS RECENTLY BEEN DEVELOPED WHICH IMPROVES THE CONVENIENCE AND ACCURACY OF VOLUME CHANGE AND PRESSURE MEASUREMENTS FOR CONSOLIDATED UNDRAINED TRIAXIAL TESTS ON SATURATED SOILS. THE ACCURACY OF VOLUME MEASUREMENTS IS IMPROVED BY REVERSING THE DIRECTION OF MOVEMENT OF THE EFFLUENT WHEN THE LIMIT OF THE VOLUME CHANGE SCALE IS REACHED, THUS ELIMINATING THE NECESSITY FOR RESETTING THE VOLUME CHANGE READING WHEN MEASURING LARGE VOLUMES. THE ACCURACY OF PRESSURE MEASUREMENTS IS IMPROVED BY USING THE SAME SENSITIVE ELECTRICAL PRESSURE TRANSDUCER FOR MEASURING ALL OF THE PRESSURES USED FOR TESTING, THUS MINIMIZING ERRORS DUE TO CALIBRATION AND ZERO SHIFT. CONVENIENCE OF USE IS AFFORDED BY SIMPLICITY OF DESIGN AND OPERATIONAL TECHNIQUE. CONSISTING ALMOST ENTIRELY OF COMMERCIALLY AVAILABLE PARTS, THE DEVICE MAY BE BUILT FOR ABOUT $65 IN ADDITION TO THE COST OF THE PRESSURE TRANSDUCER. /AUTHOR/
5 citations