Compressive strength and impact resistance of hybrid fiber reinforced concrete exposed to elevated temperatures

Abstract This paper presents a comprehensive experimental investigation to explore the effect of synthetic and natural fibers, both individual and hybrid, on the strength properties and impact resistance of concrete exposed to different elevated temperatures (27, 200, 400, and 800°C). The influence of steel, polypropylene, and sisal fibers on compressive strength and impact resistance under the elevated temperature was investigated, and a comparison was made with conventional concrete. Apart from mono‐fiber reinforced concrete, the resistance of hybrid fiber reinforced concrete containing steel‐polypropylene and sisal fibers in different hybrid combinations to impact loading and compressive strength was also evaluated. The results revealed that the incorporation of fibers helps in improving the mechanical properties of concrete both at ambient and elevated temperatures. Finally, this study confirms that mono steel fibers can be replaced with a hybrid mix containing natural fiber to improve concrete's residual hardened properties and fire resistance.