高温后混凝土性能的退化规律

Law of Performance Degeneration of Concrete After High Temperatures

利用KH-3000三维视频显微镜对高温后钢筋混凝土粘结界面区混凝土的细观结构进行观测分析,考虑了加热温度和冷却方式对混凝土性能的影响.结果表明,随着加热温度的升高,钢筋与混凝土之间的粘结性能逐渐衰退;钢筋与混凝土粘结界面区混凝土中的裂纹随之增多,且喷水冷却后裂纹更加明显.同时,给出了混凝土随温度变化的损伤演变规律.

With the KH -3000 3-D video microscope, the authors analyzed the microstructures of concrete at the RC （reinforced concrete） bonded interface after high temperatures, taking into account the influences of heating temperatures and cooling modes on the performance of concrete. The results revealed that, with the rise in heating temperature, the bonding capacities between concrete and bars gradually degenerated, while the cracks in concrete at the interface increased and were even more visible after spray cooling. Meanwhile, presented was the damage evolution law of concrete with the variation in temperature.