Electro-mechanical self-sensing response of ultra-high-performance fiber-reinforced concrete in tension

The electro-mechanical self-sensing response of ultra-high-performance fiber-reinforced concretes (UHPFRCs), a type of strain-hardening steel-fiber-reinforced concretes (SH-SFRCs), in tension was investigated. The self-sensing capacity of SH-SFRCs was significantly enhanced by using ultra-high-performance concrete (UHPC) as the matrix. The high electrical resistance of UHPC noticeably increased the magnitude of the resistivity reduction of UHPFRCs in tension to 437.7 kΩ-cm, compared to the lower values (149.1 kΩ-cm) of SH-SFRCs. UHPFRCs showed the highest gauge factor (433) until the first cracking point, whereas the SH-SFRCs with a 152 MPa compressive mortar matrix showed the highest gauge factor (73.7) within the strain-hardening region. An embedded copper wire mesh type electrode efficiently reduced the electrical polarization.