Strain-hardening Behaviour of Hybrid Fiber Reinforced Cement Composites

Abstract

This paper reports the results of an experimental study on the strain-hardening behaviour of hybrid fibre reinforced cement composite under four-point bending. Two types of fibres (steel and PVA) were used as hybrid reinforcement in several volume fractions. The total volume fraction of fibres was kept constant at 2.5% to maintain a workable mix. Effect of both high volume fly ash (used as partial replacement of cement) and fibre aspect ratio on the strain- hardening behaviour was investigated. Among composites with different volume ratios of steel and PVA fibres, the composite with 1% steel and 1.5% PVA was found to show the highest flexural strength and deflection capacity. Ultimate flexural strength values as high as 11.2 MPa and toughness indices as high as 135 have been achieved. Strain-hardening behaviour and multiple cracking were observed in all hybridfibre composites