Resilient modulus, permanent strain
This method covers procedures for preparing and testing untreated subgrade soils and untreated base/subbase materials for the determination of resilient modulus (Mr) under conditions representing a simulation of the physical conditions and stress states of materials beneath flexible pavements subjected to moving wheel loads .A repeated axial cyclic stress of fixed magnitude, load duration (0.1 s), and cycle duration (1.0 to 3.1) is applied to a cylindrical test specimen. During testing the specimen is subjected to a dynamic cyclic stress and a static-confining stress provided by means of a triaxial pressure chamber. The total resilient (recoverable) axial deformation response of the specimen is measured and used to calculate the resilient modulus.
2.8 to 3.4 in diameter specimen with a length to diameter ratio of 2, depending on the maximum grain size.
Resilient, modulus, base/subbase, subgrade, flexible testing, cyclic loads, permanent strain.