Effect of recycled polymer fibre on dynamic compressive behaviour of engineered geopolymer composites.

To enhance the cost-effectiveness and sustainability of engineered geopolymer composites (EGC), polyvinyl alcohol (PVA) fibres in EGC can be partially replaced with recycled tyre polymer (RTP) fibres. This paper presents a systematic experimental study on the effects of PVA fibre volume fraction (1.0%, 1.5% and 2.0%) and RTP fibre content (0.25%, 0.5%, 0.75% and 1.0%) on the dynamic compressive behaviour of EGC under various strain rates (54.43–164.13 s−1). Results indicate that the flowability, quasi-static compressive strength and elastic modulus of EGC reduce with the increase of PVA fibre content, where the reductions can be effectively mitigated by adding RTP fibres. The dynamic compressive properties of all investigated mixtures including dynamic compressive strength, dynamic increase factor (DIF) and energy absorption capacity show a pronounced strain rate dependency which can be well described using the proposed equations for DIF against strain rate ranging from 10−5 s−1 to 103 s−1 with R 2 values of mostly greater than 0.9. The dynamic compressive properties of EGC are enhanced with the increasing PVA fibre dosage under various strain rates while replacing PVA fibre with a certain amount of RTP fibre (0.25% and 0.5%) can result in better dynamic compressive properties compared to EGC with 2.0% PVA fibre. EGC containing 1.75% PVA fibre and 0.25% RTP fibre can be considered as the optimal mixture given its superior quasi-static and dynamic compressive properties in comparison with EGC with 2.0% PVA fibre. [ABSTRACT FROM AUTHOR]