فهرست نشریات علمی دسترسی آزاد ایران

Heavyweight geopolymer concrete (HWGC) can experience severe degradation when subjected to elevated temperatures and impact loading; however, its combined thermo-mechanical response remains insufficiently documented. This study experimentally evaluates HWGC slabs incorporating electric arc furnace (EAF) slag as a dense aggregate, together with optimized ground granulated blast furnace slag–microsilica (GGBFS–MS) blends (10–30%) and steel fibers (SF, 0.25–1%). Compressive strength and drop-weight impact tests were performed after 28 days, and residual behavior was examined following exposure to 300 °C and 600 °C for one hour. Results showed that 20% MS replacement provided the best balance between strength and thermal stability, while 0.75% steel fiber markedly enhanced impact resistance, energy absorption, and rebound impulse. The optimized mixture achieved a 66.6% increase in effective impact force compared with the control and demonstrated superior strength retention after heating. SEM and XRD analyses confirmed denser gel formation, refined microstructure, and improved fiber–matrix bonding. Overall, the findings provide clear experimental evidence that optimized HWGC mixtures can sustain mechanical efficiency and durability under severe combined thermal and impact conditions.