An Experimental Investigation on Assessment of Residual Mechanical Performance of Basalt Fiber Reinforced High Strength Concrete at Elevated Temperature

This research explores the effect of basalt fibers (BFs) added in high strength concrete (HSC) to tailor its mechanical and microstructural response on being exposed to fire. Thermo-mechanical behavior of reference and modified formulations was monitored in ambiance alongside the exposed elevated temperatures till 100°C, 200°C, 400°C, 600°C, and 800°C. The dose of BFs was maintained as 1% and 2% by weight of cement in modified HSC formulations. The specimens were subjected to the controlled heat ramp of 5°C/min, to attain the desired temperature elevation with a hold time of 150 min. The heated specimens were then cooled by air till ambiance to test for residual properties. The test results revealed significant improvement in thermo-mechanical properties of BFs reinforced HSC formulations after being exposed to fire. Micro-forensics evidenced the homogenized distribution of BFs alongside their crack arresting actions throughout the matrix, contributing to the added residual performance. The matrix morphology of BFs reinforced HSC was also monitored to endorse any physical or chemical change in the hydration product. Moreover, numerical equations based on statistical analysis were formulated that can predict the fire behavior of modified HSC samples with BFs.