RESILIENT MODULI OF GRANULAR-MATERIALS

The six most commonly encountered aggregates that are used as sub-base s/bases of roadways in Oklahoma were selected and tested under cyclic loading to evaluate the Resilient Modulus (RM) by using the AASHTO T29 2-91I and T294-92I methods. The gradation of the specimens met the Okl ahoma Department of Transportation 1988 specifications for type A (fin e) and type B (coarse) materials. A series of exploratory tests were p erformed to assess the effect of gradation, compaction method, specime n size, and testing procedures on the RM values. The values reported o r suggested by various agencies were compared with the values obtained from the present study. Statistical correlations were established bet ween RM and the California bearing ratio, and between RM and cohesion and friction angle. It was observed that, for a given gradation and bu lk stress, the RM values obtained in this study were slightly lower th an those reported in the literature; the influence of gradation and co mpaction method on RM values were less significant compared to the eff ects of the stress state. Higher RM values were obtained from the T294 -92I testing procedure than those obtained by the T292-91I testing pro cedure. The RM values for 10.16-cm specimens were higher than those fo r 15.24-cm specimens, and a satisfactory correlation did exist between the RM values and the cohesion and friction angle.