Stress–Deformation Response of Rigid–Soft Particulate Mixtures under Repetitive Ko Loading Conditions

Abstract

Sand–rubber mixtures used in transportation infrastructure experience repetitive loading. Hence, in this study, the mixtures of rigid sand particles and soft tire chip particles with two different size ratios at varying tire chip fractions (TF) by weight were prepared, and repetitive loading tests were performed for 10,000 cycles at 100 kPa stress amplitude (Δσ). The results of this study demonstrate that significant volume contraction occurs for the tested rigid-soft mixtures during repetitive loading due to the continuous accumulation of plastic strain. Most notably, this study reveals that the magnitude of elastic strain recovery of the tested mixtures decreases with increasing cyclic loading number, reflecting the transition of the structural skeleton from the contacts between sand-to-rubber and/or rubber-to-rubber to those between sand-to-sand and/or rubber-to-sand under repetitive loading conditions with constant Δσ. The effects of TF and size ratio on the compressibility of the tested mixtures are also evaluated in this study.