Study on the post-fire properties of concrete with recycled tyre polymer fibres

This paper presents the results of an experimental study conducted to evaluate the effect of recycled tyre polymer fibres (RTPF) on the mechanical and durability properties of concrete after high temperature exposure. RTPF were used as an alternative to the commonly used polypropylene fibres (PPF) in concrete. Therefore, five different concrete mixes were tested: plain concrete, four mixes with 1 and 2 kg/m3 of RTPF and PPF, respectively. The specimens were tested under ambient conditions and after exposure to a predefined elevated temperature of up to 500 degrees C, considering the fibre decomposition temperatures determined by the DTA/TG analysis. The results showed that when RTPF was used in concrete up to 2 kg/m3, high temperatures did not cause further deterioration of the mechanical and durability properties of concrete due to their melting. On the contrary, certain benefits of RTPF were found compared to PPF, possibly due to the higher amount of residue at high temperatures.