Bending and impact strength behaviour of crumb rubber concrete

Abstract

This research is aimed at investigating the strength, deflection, impact energy absorption, and ductility index of the treated rubberized concrete named Crumb Rubber Aggregate Concrete (CRAC). Fine aggregates are achieved by partial replacement of waste tire rubber aggregates. The crumb rubber is reduced to the required size by mechanical grinding or by chiselling. An experimental examination is conducted based on the partial replacement of fine aggregates in the concrete towards the identification of the potential of pre-treated rubber aggregates using the weigh batching method. The rubber fibres are used as additives to the total weight of concrete. The property of rubberized concrete containing crumb rubber is treated with three different acidic solutions (CH3COOH (5%), H2SO4 (35%) and HCL (5%)). Various tests are carried out on the fresh and hardened state of CRAC named workability, compressive strength, split tensile strength, and flexural strength. Then, conventional concrete and untreated rubberized concrete were tested and compared. The results highlight the positive effects of the flexural strength of concrete containing recycled rubber, surface modified when concrete mixes of conventional concrete are compared. The results indicate that the compressive and split tensile strength increases on the percentage of replacement of crumb rubber with an added 2.0% rubber fiber increases. The workability of concrete increases while increasing the replacement percentage of fine aggregate with crumb rubber due to its low water penetration property. Further, the study proved that a 10% replacement of crumb rubber aggregates with an addition of 2.0% rubber fibers are optimal and safest alternative in all the mechanical properties and also to use acetic acid for the pre-treatment of rubber in the project newline