A multifunctional material, can be used to protect and monitor the degraded concrete infrastructure, which possessing good damage tolerance, whilst providing a self-sensing capacity that designed to specifically diagnose cracking. Strain-Hardening Cementitious Composites (SHCC) presents superb tensile ductility and pseudo strain-hardening property. In this paper, the electrical and mechanical properties of SHCC incorporating Carbon Black (CB) nano-particles and Air Entraining Agent (AEA) are studied. The electrical response of SHCC, HFA-SHCC (high fly ash SHCC) and CB-SHCC under direct tension was investigated experimentally by four-point probe test. The experimental results showed that the bulk resistivity of all specimens increased with the crack propagation, and the increase ratio in inelastic phase was much higher than that in elastic phase. Due to the addition of CB and AEA, the strain hardening behavior with tensile strain capacity of CB-SHCC was about 4%, and reduced crack widths after tensile loading was 22 μm. Furthermore, CB-SHCC specimens showed the most sensitive response to first cracking, which could be potentially utilized to detect micro cracking by means of variation in resistivity.

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