Effect of micro steel fibre contents on compressive and self-sensing properties of polyethylene fibre-reinforced cement composite (PE-FRCC) in cyclic compression

Abstract

This study is conducted to develop a cement-based strain-detecting sensor with high cost-effectivity, large strain measuring range and good compatibility with concrete infrastructures. The paper describes experimental results on the compressive properties and piezoresistive behaviour of polyethylene(PE) fibre-reinforced cement composite(PE-FRCC) with different contents of micro steel fibres (SFs) under cyclic compression. The synthetic PE fibres were added into cement-based mortar to improve the strain capacity in compression and micro SFs at 0.25-1.5% by volume fraction of cement were incorporated to improve the compressive properties and electrical conductivity. Test results show that for the PE-FRCC with compressive strength of 32MPa, the increase in the micro SF content to 0.5% increased about 45% in the compressive strength compared to PE-FRCC without SFs. The addition of micro SFs into PE-FRCC improved the compressive properties, such as modulus of elasticity and lateral confinement. The incorporation of micro SFs is also effective to reduce the signal noise in the relationship between fractional change in resistance (FCR) and axial strain of PE-FRCC. PE-FRCC sensor with more 1.0% micro SF (PE0.75+SF1.00 composite) possess a strong linear relationship between FCR and axial strain during repeated compression at different stress amplitudes.