Correlation between resilient modulus (MR) and constrained modulus (MC) values of granular materials

Abstract

The resilient modulus (MR) value of unbound aggregates has been widely accepted as the principal mechanical property required in the mechanistic-empirical design/analysis of pavement structures. Resilient modulus measured through repeated triaxial load test is highly desirable to characterise granular materials. However, because of the complexities encountered with this test, other laboratory tests would be desirable if a reliable correlation could be established.Reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) have potential to be used as base and subbase material in substantial percentage to achieve economy and to minimise the undesirable environmental effects linked to the use of virgin aggregates. This paper presents a correlation developed between MR value and constrained modulus (MC) value on the basis of experimental results obtained for 32 reconstituted granular samples containing virgin aggregates, RAP and RCA materials. Proposed model considers the effect of stress state through the experimentally determined MC value while model parameters are correlated to the percentage of RAP materials in the reconstituted blends. Statistical analysis of the suggested correlation by t-test demonstrates encouraging results in terms of its strength and significance.