Piezoresistive properties of cementitious composites reinforced by PVA fibres

The use of fibres to enhance the ductility of cementitious composites has been extensively studied for the past few years. The addition of polymeric or metalic fibres with random orientation to the composite or even natural long and aligned fibres demonstrated a very successful reinforcement capable to reach a high mechanical performance. Other property that has been studied is the use of those composites to work as strain sensors. To develop piezoresistive properties on cementitious composite, the addition of conductive materials is necessary. This research evaluated the incorporation of different volumes of multi-wall carbon nanotubes on the piezoresistive properties of strain hardening cementitious composites (SHCC) reinforced by PVA fibres. Through impedance measurements the opening of the cracks under tensile loading was studied. The characterization of this material can help on the understanding of self-sensing properties, adding value to the SHCC used by the repair industry and will contribute to the continuous infrastructure monitoring.