This investigation assessed the performance of polyvinyl alcohol (PVA) fibres of 6 mm and 12 mm length in concrete. Based on total concrete volume, four fibre fractions (0·125, 0·25, 0·375 and 0·5%) were evaluated for their effect on fresh and hardened properties of PVA fibre reinforced concretes (PVA-FRCs). Fly ash was also used as partial replacement of Portland cement in all the mixes. By carrying out a comprehensive set of experiments (compressive strength, splitting tensile strength, modulus of elasticity, modulus of rupture and residual flexural strength), it was observed that PVA fibre significantly enhances the static mechanical properties of concrete as well as improving its post-peak response and ductile behaviour.nerally withstood higher loads than SFRC. At room temperature, the axial tensile strength of NSFC was the highest at 2·66 MPa, which was 4·29 times that of NC and 52·9% higher than that of SFRC. The peak stress of NFSC was approximately 1·8 times that of SFRC. At 400°C, the axial tensile strength of NSFC was 3·09 MPa, 9·2% higher than that of SFRC and 119·7% higher than that of NC. At the test temperature, the fracture energy of NSFC was the highest, followed by SFRC, with NC showing the minimum fracture energy.

The current study assesses the drying shrinkage behaviour of polyvinyl alcohol fibre reinforced concrete (PVA-FRC) containing short-length (6 mm) and long-length (12 mm) uncoated monofilament PVA fibres at 0.125%, 0.25%, 0.375%, and 0.5% volumetric fractions. Fly ash is also used as a partial replacement of Portland cement in all mixes. PVA-FRC mixes have been compared to length change of control concrete (devoid of fibres) at 3 storage intervals: early-age (0–7 days), short-term (0–28 days), and long-term (28–112 days) intervals. The shrinkage results of FRC and control concrete up to 112 days indicated that all PVA-FRC mixes exhibited higher drying shrinkage than control. The shrinkage exhibited by PVA-FRC mixes ranged from 449 to 480 microstrain, where this value was only 427 microstrain in the case of control. In addition, the longer fibres exhibited higher mass loss, thus potentially contributing to higher shrinkage.