Development and properties of cost-effective self-sensing Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC) incorporating steel slags

This study examined the electrical and self-sensing capacities of ultra-high performance fiber-reinforced concrete (UHPFRC) with and without steel slag powder. The inclusion of steel slags provides a reliable way to enhance the electrically conductive and self-sensing capabilities of UHPFRC, which is composed of cement, silica fume, and steel fiber. The conductibility of UHPFRC and its response to external loading were investigated. Additionally, through 3D analysis of fiber structure and pore distribution, the conductive mechanisms were revealed. The results show that the addition of steel slags powder (SSP) can improve both mechanical properties and flowability. The maximum fractional change in electrical resistivity under compressive and flexural loads reached 37.6% and 54.1 %, respectively. However, the conductive model under compressive loading differs from that under flexural loading. Furthermore, an analysis of carbon emissions and material costs revealed that using SSP reduced carbon emissions by 45.2-96.4 % and lowered costs by 41.8-88.8 %, making this approach both economically and environmentally advantageous.