Study on static and dynamic mechanical properties of steel fiber self-compacting concrete after heating in a high-temperature

While supporting impact loads, steel fiber self-compacting concrete (SFRSC) is frequently impacted by temperature loads. Therefore, it is essential to investigate how the SFRSC responds mechanically when impact and high temperature are combined. To ascertain the effects of temperature and impact load on the static and dynamic mechanical characteristics of SFRSC, static and dynamic mechanical tests were performed on SFRSC treated at 25 & DEG;C, 100 & DEG;C, 200 & DEG;C, 400 & DEG;C, 600 & DEG;C, 800 & DEG;C, and 1000 & DEG;C using the RMT-150C system and SHPB, respectively. The laws of mechanical response changes were presented from the viewpoints of the stress-strain relationship, compressive strength, DCF, DSF, elastic modulus, XRD phase analysis, and failure morphology. Systematically examined were the effects of temperature on mechanical behavior when impact and high temperature are coupled, including the temperature strengthening effect, temperature weakening effect, critical temperature, and strain rate effect. A damage-type visco-elastic constitutive model taking temperature into account was created by incorporating the temperature effect coefficient K and the damage factor D. According to the results, static and dynamic mechanical characteristics were improved at temperatures of 100 and 200 & DEG;C, but they dramatically degraded at 400-1000 & DEG;C, and strain rate sensitivity significantly increased with temperature.