Surface Treatment of Steel Fibers Using Solid Waste Solutions and Cement Kiln Tail Gas for Enhanced Reinforcement of Ultra-High Performance Concrete (Uhpc)

Abstract

This study develops a sustainable steel fiber modification method using industrial waste (calcium carbide slag solution, CCSS; cement slurry waste solution, CSWS) and cement kiln CO2-rich flue gas (80-100°C) to enhance ultra-high performance concrete (UHPC). Surface treatment forms 1-2 μm CaCO3 particles and C-S-H gel on fibers, increasing roughness and interfacial bonding. CSWS-treated fibers boosted UHPC compressive strength by 21.6% (164.9 MPa) and flexural strength by 40.9% (42.4 MPa). Pullout tests revealed doubled energy absorption through chemical/physical interlocking. The process converts CCS, CSW, and CO2 into functional materials, aligning with circular economy principles. This scalable, low-energy technique enables eco-friendly production of high-performance UHPC while addressing industrial waste and carbon emissions..

Keywords: Steel fiber surface treatment, Solid waste utilization, UHPC, Interfacial bonding, Low-carbon modification