The single and hybrid use of steel and basalt fibers on high-temperature resistance of sustainable ultra-high performance geopolymer cement mortars

Abstract

This paper primarily examines the flowability, physical appearance, mass loss, residual compressive strength (RCS), and residual flexural strength (RFS) properties of steel (ST) and basalt (BA) fiber-added sustainable ultra-high performance geopolymer cement (UHPGPC) mortars exposed to high-temperature effects. According to the results obtained, ST and BA fibers adversely influence the workability properties of UHPGPC mortars and thus significantly reduce the spreading diameters of the mortars. However, ST and BA fibers substantially improve the RCS and RFS capacities of UHPGPC specimens exposed to high temperatures because they have a powerful bonding effect with the matrix and effectually restrict the development of micro- and macro-cracks with their bridging effect. Furthermore, this phenomenon is slightly more effective in hybrid form than using ST and BA fibers.