Development of smart engineered cementitious composites with integrated self-sensing capability and enhanced tensile ductility

Abstract

This work elucidates the coupled mechano-electrical behaviour of carbon black-engineered cementitious composites (CB-ECC) by resolving critical conflicts between tensile ductility (≥6.7% strain capacity) and electrical conductivity. The CB content near the percolation threshold of 1.0%–1.5% can synchronise strain-hardening characteristics with stable piezoresistive response through deliberate tailoring of ECC’s components. Excessive CB content (≥2.0%) leads to agglomeration, increased porosity, and reduced mechanical properties, while also destabilising the conductive network under wet conditions. The developed self-sensing ECC represents a class of multifunctional smart materials that intrinsically integrate structural load-bearing capacity with real-time strain/stress monitoring functionality, enabling simultaneous large deformation capacity and highly sensitive piezoresistive response. These findings provide critical insights into material design and optimisation for intelligent infrastructure applications.