Mechanical and electrical characterisation of steel fiber and carbon black engineered cementitious composites

Engineered cementitious composite (ECC) is one kind of cement based material fabricated with various types of functional fillers, which is of superior tensile resistance and energy absorption. ECC made some conductive fillers such as steel fiber (SF) and carbon black (CB) also presents great potential in self-sensing. In this study, the mechanical property, conductive performance and self-sensing capacity of two types of ECC, i.e. SF-ECC fabricated with 0.58% steel fiber and 1.75% PVA, and CB-ECC casted with 1% weight ratio to cementitious materials and 1.75% PVA, have been investigated by experiments and numerical simulation. Four point bending test synchronising AC resistance measurement has been implemented to compare the stress strain relationship with resistance variation. Discrete element method (DEM) has been applied to simulate the crack density development during the flexural test. The outcomes are also compared between these two types of ECC to evaluate the sensitivity of self-sensing property, which will contribute to the ECC optimisation to balance the loading and self-sending capacity.