FACTORS INFLUENCING THE RESILIENT RESPONSE OF GRANULAR MATERIALS

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/