Properties of local ultra-high-performance concrete with low dosage of polyvinyl alcohol and steel fibre

Abstract

Abstract Ultra-high-performance concrete (UHPC) delivers better durability and mechanical properties than normal-strength concrete. However, conventional UHPC requires heat treatment and a high dosage of high tensile steel fibre to achieve a compressive strength of 120 MPa. The present study was conducted to test a local UHPC with low fibre dosage and without heat treatment by incorporating different polyvinyl alcohol (PVA) fibre and steel fibre. The fibres included in the experimental works were 30 mm PVA macro fibre, 8 mm PVA fibrin and hooked end steel fibre with 35 mm in length. Four series of UHPC were studied, which consist of plain UHPC mix and three fibre-reinforced UHPC mixes. 1% fibre volume was incorporated into all the fibre-reinforced mixes. The mixes were tested for compressive strength, modulus of rupture, drying shrinkage and porosity The UHPC had a compressive strength of more than 120 MPa and modulus of rupture from 8 to 11 MPa. The drying shrinkage of all the UHPCs was less than 255με when cured at 100% relative humidity. The porosity recorded for the UHPC was 2%. Current findings indicated that steel fibre reinforced UHPC performed better than UHPC with PVA fibre in terms of mechanical properties However, UHPC with PVA fibrin performed better in terms of the drying shrinkage. In conclusion, UHPC with more than 120 MPa can be achieved with normal synthetic and steel fibre without special treatment.