高温后再生混凝土的残余抗折强度

Residual Flexural Strength of Recycled Concrete After Elevated-temperatures

完成了150块不同再生粗骨料取代率（0%、30％、50%、70％、100％）下再生混凝土棱柱体试块在20℃～800℃下的高温试验。通过对高温中和高温后试验现象与数据的对比，研究了高温后再生混凝土的残余抗折强度，分析了高温后再生混凝土的残余抗折强度与经历温度之间的相互关系与变化特点，同时与已有高温后再生混凝土的残余抗压强度进行了对比分析。最后，提出了基于试验统计的再生混凝土残余抗折强度与经历温度之间的建议公式。结果表明：随经历温度的升高，高温后再生混凝土的残余抗折强度整体上逐渐下降；与残余抗压强度相比，再生粗骨料取代率对高温后再生混凝土的残余抗折强度影响不明显。

Based on the flexural test of 150 prism specimens after elevated temperatures ranging from 20℃ to 800 ℃, the fire performance of recycled aggregate concrete （RAC） with different replacement percentages of recycled coarse aggregate （RCA） （i. e. 0%, 30%, 50%, 70%, 100%） was investigated. Through contrasting and analyzing the test phenomenon as well as the data at elevated-temperatures and after elevated-temperatures, the residual flexural strength of recycled concrete was studied, meanwhile, the varying characteristics and the relationships between the residual flexural strength of recycled concrete and exposed temperatures were analyzed. Finally, the suggestion formulas of residual flexural strength of recycled concrete and exposed temperatures in terms of the testing statistics were proposed. The results show that the residual flexural strength of recycled concrete after elevated-temperatures decreases with the elevating of exposed temperatures, and the effect of the replacement percentage of RCA on the residual flexural strength of recycled concrete after elevated-temperatures is unnoticeable compared to that of the residual compressive strength.