Experimental Study on Steel-Fiber-Reinforced Scoria Aggregate Concrete Subjected to Freeze-Thaw Cycles and Then Exposure to Elevated Temperatures

Steel-fiber-reinforced scoria aggregate concrete (SFSAC), which contains and steel fiber, was developed to reduce the environmental impacts improve energy efficiency of buildings. Experimental studies were performed. The test variables included fiber volume contents (0%, 0.5%, 1.0%, 1.5%), freeze-thaw cycles (0 25 times), temperature (20 °C, 200 400 600 800 °C). Mass loss, relative dynamic elastic modulus, mechanical properties, variation pattern complete stress–strain curves analyzed through rapid freeze-thaw, high-temperature, tests. results showed that after then exposure high temperatures, surfaces SFSAC specimens spalling accompanied by dense cracks. Moreover, residual properties steel-fiber-reinforced natural (SFNAC) better than those (NAC). Although incorporation cannot significantly anti-freezing performance SFSAC, it can optimal amount is 1%, considering economic cost factors. both SFNAC same trend i.e., peak stress decreased, strain increased, descending section tended level off. Finally, based on damage mechanics theory, role fibers in uniaxial compression process (SAC) effect high-temperature tests model constitutive proposed as being able highly accurately reflect overall characteristics tests, also provided a theoretical basis for resistance assessment structures cold regions.