Behaviour of hybrid fibre reinforced high-strength lightweight aggregate concrete

An experimental study has been carried out to understand the behaviour of high-strength lightweight aggregate concrete reinforced with mono and hybrid fibres. Control, mono (single), double hybrid and triple hybrid fibre reinforced concretes were cast using macro-fibres of steel and micro-fibres of steel and polypropylene. This paper presents the segregation resistance, compressive and tensile strength, flexural toughness, stress–strain behaviour, shrinkage and water absorption of lightweight aggregate concrete C with and without hybrid fibres. The results indicate that the stability of lightweight aggregate (segregation resistance) increases when LWAC is reinforced with fibres in general and hybrid fibres in particular. Lightweight aggregate concrete with mono and hybrid fibres has shown a significant increase in tensile strength when compared with plain lightweight aggregate concrete; however, it has shown a marginal decrease in compressive strength. Lightweight aggregate concrete with mono and hybrid fibres displayed a pseudo hardening response in the post-crack region, while lightweight aggregate concrete with hybrid fibres has shown superior performance to lightweight aggregate concrete with mono fibres in terms of flexural toughness, post-crack strength and durability. The effect of water to cement ratio on the properties of lightweight aggregate concrete with hybrid fibres was also studied.