Evaluation of laboratory performance of self-consolidating concrete with recycled tire rubber

This study investigated the performance of early-aged and hardened self-consolidating concrete (SCC). Rubber-modified SCC mixtures were prepared with 15% as-received crumb rubber and 15% and 25% NaOH-treated crumb rubber based on volume of fine aggregates. The SCC sampled without rubber aggregates were cast as the control groups. The slump test, V-flannel flow test, and U-box test were conducted to evaluate the fresh properties of different types of rubber modified SCC. The fresh properties showed slightly reduced flowability with replaced rubber particles. The measured compressive and splitting tensile strength of rubber-modified SCC concrete were reduced in comparison with the control mixture. However, the surface-treated rubberized concrete had higher mechanical strength than as received rubberized concrete due to better bonding at the interface. The measured ultrasonic transmission speed decreased with the increasing rubber content in concrete and these results also indicated the reduced dynamic modulus. The transport property evaluated from the electrical resistivity measurement indicated the decreased permeability with added rubber content. The durability performances (including alkali-silica reaction and drying shrinkage) of SCC mortar samples were generally improved with rubber-modified samples. Overall study showed that the rubber-modified SCC can maintain good workability and mechanical properties and enhance durability with reduced environmental impacts. (C) 2018 Elsevier Ltd. All rights reserved.