Resilient Moduli of Granular Materials

Abstract

The six most commonly encountered aggregates that are used as subbases/bases of roadways in Oklahoma were selected and tested under cyclic loading to evaluate the Resilient Modulus (RM) by using the AASHTO T292‐91I and T294‐92I methods. The gradation of the specimens met the Oklahoma Department of Transportation 1988 specifications for type A (fine) and type B (coarse) materials. A series of exploratory tests were performed to assess the effect of gradation, compaction method, specimen size, and testing procedures on the RM values. The values reported or suggested by various agencies were compared with the values obtained from the present study. Statistical correlations were established between RM and the California bearing ratio, and between RM and cohesion and friction angle. It was observed that, for a given gradation and bulk stress, the RM values obtained in this study were slightly lower than those reported in the literature; the influence of gradation and compaction method on RM values were less significant compared to the effects of the stress state. Higher RM values were obtained from the T294‐92I testing procedure than those obtained by the T292‐91I testing procedure. The RM values for 10.16‐cm specimens were higher than those for 15.24‐cm specimens, and a satisfactory correlation did exist between the RM values and the cohesion and friction angle.