掺引气剂活性粉末混凝土高温后强度退化及质量损失研究

摘要

对不同钢纤维体积掺量的掺入引气剂的活性粉末混凝土(简称RPC)试件及未掺引气剂的RPC试件进行了高温后力学性能测试和质量测量,考察了RPC在掺入引气剂或未掺引气剂时,受火温度对不同钢纤维体积掺量的RPC试件的抗压强度、抗折强度、折压比及质量损失的影响.试验结果表明,未掺引气剂的RPC在超过200 ℃时爆裂,且在200 ℃之前强度变化趋势与掺引气剂RPC的强度变化趋势一致.随着试件所受高温温度的升高,试件强度整体呈现阶梯下降趋势;400 ℃以前,钢纤维体积掺量对RPC强度影响甚微,400 ℃以后,钢纤维体积掺量越高,残余强度百分比越大.不同钢纤维体积掺量RPC试件的质量损失率趋势一致,纤维掺量对RPC质量损失率影响不大.%By testing mechanical properties and mass loss of different steel fiber volume content of mixing air-entraining RPC and no mixing air-entraining RPC after high temperature,test compressive strength of RPC after high temperature and mass loss of RPC with different volume content steel fiber was inspected.After high temperature,no mixing air-entraining RPC burst over 200 ℃,and the strength of no mixing air-entraining RPC showed the same trend with mixing air-entraining RPC before 200 ℃.The results of strength test of mixing air-entraining RPC showed a downtrend with increase temperature.Before 400 ℃,steel fiber volume content has little effect on the strength of RPC.After 400 ℃,the higher the volume content of steel fiber,the greater the relative residual strength of RPC.After high temperature,the mass loss of RPC with different volume content steel fiber showed the same trend.