超低温下钢筋混凝土梁受弯承载力研究

Study on bending bearing capacity of reinforced concrete beams at super-low temperature

采用自行开发的低温夹具,对6根钢筋混凝土梁在-180℃~20℃温度下进行了单调静力加载试验。通过试验,研究了低温下钢筋混凝土梁的破坏模式和破坏机理,分析了温度对梁受弯性能的影响。结果表明,钢筋混凝土梁的承载力随温度的降低而增大,和室温相比,温度在-40℃、-80℃、-120℃、-160℃、-180℃时,开裂荷载分别提高23.2%、66.0%、77.3%、112.4%和187.6%;屈服荷载分别提高39.4%、52.1%、124.6%、147.5%和205.6%;极限承载力分别提高26.5%、39.4%、91.5%、112.3%和160.6%。根据超低温材料性能及钢筋混凝土梁受弯性能的试验结果,给出了超低温下梁截面受弯承载力的计算公式。

Monotonic static loading tests for 6 reinforced concrete beams were conducted at temperature ranged from-180℃ to 20℃ using the jig and fixture for low temperature designed by the authors.The failure modes and mechanism of reinforced concrete beams under low temperature were investigated.The tests results showed that the bearing capacity of the beam increases with the decrease of the temperature,the cracking load of the beams increase 23.2%,66.0%,77.3%,112.4% and 187.6%;the yielding load of the beams increase 39.4%,52.1%,124.6%,147.5% and 205.6%;the bearing capacity of the beams increase 26.5%,39.4%,91.5%,112.3% and 160.6% respectively at the temperature of-40℃,-80℃,-120℃,-160℃ and-180℃ comparing with that at the temperature of 20℃.The calculation method for the bearing capacity of beams under low temperature were finally proposed based on the experimental results.