Early-age dynamic moduli of crumbed rubber concrete for compliant railway structures

Abstract

Heavy freight or high speed rail operations cause dynamic aggressive environments for structural materials in a railway system, resulting in higher wear and degradation rate of traditional brittle cementitious materials. As such, the improvement in fundamental dynamic properties of the material is crucial. In this study, the focus is placed on the development of a concrete damping enhancement using crumb rubber, which has significant potential to mitigate pressing issues in modern railway industry such as railseat abrasion and impact damages in concrete sleepers, thermal expansion crack of track slabs, and so on. Also indirectly, the utilization of crumb rubber will enhance the recycling options of rubber tire wastes, which are not biodegradable. This paper will focus only on the early-age dynamic moduli of the engineered concrete using modal excitation technique. The comparative study to evaluate the influence of crumb rubber participles highlights vital changes in dynamic elasticity and damping coefficients. This insight will establish a novel material design for precast and prestressed members where initial bonding and elastic shortening is critical for serviceability criteria.