再生混凝土梁受弯性能试验研究

Experimental Research on Flexural Property of Recycled Concrete Beam

摘要:

对再生混凝土梁进行受弯性能试验后发现，当再生粗骨料(RCA)取代率（质量分数）为40%，70%和100%时，再生混凝土梁极限承载力较普通混凝土梁分别降低了1.5%，4.1%和106%；随着再生粗骨料取代率的增加，再生混凝土梁下部根状裂缝数目增多、间距减小.研究表明：平截面假定适用于再生混凝土梁，再生混凝土梁的破坏形态及承载力挠度曲线与普通混凝土梁相似；现行规范中开裂弯矩公式、极限承载力公式和挠度计算公式不适用于再生混凝土梁，建议将挠度计算值乘以1.3，开裂弯矩和极限承载力计算值乘以与再生粗骨料取代率相关的修正系数.

Abstract:

Experimental research on flexural property of recycled concrete beams was carried out. Compared with ordinary concrete beams, its ultimate bearing capacity can be reduced by 1.5%，4.1% and 106% when the replacement ratio (by mass) is 40%，70% and 100% of test beams. With the increase of recycled aggregate content，the root crack number of the lower part of test beams increases and the crack spacing decreases. The results show that the plane section assumption is applicable for recycled concrete beams, its failure pattern and bearing capacity deflection curve are similar to normal ones. The present cracking moment, ultimate load bearing capacity and deflection formula in code are no longer applicable. It may be suggested that the deflection calculation value should be multiplied by 1.3, the cracking moment and ultimate bearing capacity formula should be multiplied by the corresponding correction coefficient.