Experimental study on dynamic compressive behaviour of recycled tyre polymer fibre reinforced concrete

Abstract The effect of recycled tyre polymer fibre (RTPF) on mechanical and durability performance of concrete has been increasingly studied in recent years, primarily because of the economic and sustainable feasibility of RTPF's application in construction industry. This paper presents an experimental study on workability, static compressive strength and dynamic compressive properties of concrete reinforced with RTPF with various fibre dosages (i.e. 1.2, 2.4, 4.8 and 9.6 kg/m 3 ) that have not been extensively investigated. Results indicate that the dynamic compressive properties including dynamic compressive strength, energy absorption capacity, ultimate strain and dynamic increase factor of all mixtures were highly sensitive to the strain rate. The optimal RTPF content was found to be 2.4 kg/m 3 (i.e. 0.2% fibre volume fraction (V f )) considering fresh and hardened properties, as adding this content into concrete induced the most development in dynamic compressive strength (with the highest increase of 12.9%), fracture energy (with the highest improvement of 54.4%) and total energy absorption (with the largest enhancement of 26.4%). It was found from scanning electron microscope (SEM) image analysis that RTPF exhibits bridging performance with no obvious fracture on its surface, and 0.1% V f of PPF could be replaced by 0.2% V f of RTPF for concrete.