Sustainable design of high strength ECC using steel slag as fine aggregate: Toward waste valorization and environmental benefits
Chenyu Lu, Qiang Shen, Zhigang Zhang
Abstract
The high cost and carbon emissions of Engineered Cementitious Composites (ECC) limit their broad application. This study explores using steel slag particles (SSP) as a sustainable substitute for silica sand in developing green, high-strength ECC. The mechanical properties and micromechanical mechanisms were evaluated at different SSP substitution ratios. Results show that SSP enhanced matrix density and reduced porosity. Macroscopically, SSP improved tensile strain-hardening behavior; the mixture with 50 % SSP achieved optimal performance, exhibiting compressive strength of 84.47 MPa, tensile strength of 8.58 MPa, and tensile strain capacity of 8.18 %. Microscopic analysis indicated that SSP strengthened the fiber/matrix interface, increasing the PSH energy index, which explains the improved ductility. Additionally, SSP replacement reduced material cost by approximately 35 % and carbon emissions by approximately 42 %, while maintaining mechanical performance. This work supports sustainable ECC development and promotes large-scale utilization of industrial solid waste in construction.