再生混凝土简支梁受弯性能试验研究

Experimental research on bending performance of recycled concrete beams

通过再生粗骨料取代率分别为0,30%和75%的3根再生混凝土简支梁的抗弯性能试验,探讨了再生混凝土受弯构件正截面受力变形性能和破坏特征。结果表明:再生混凝土适筋梁破坏过程和破坏模式与普通混凝土梁基本相同;正截面平均应变服从平截面假定;再生混凝土梁的开裂弯矩、屈服弯矩和极限弯矩随着再生粗骨料取代率的增加而减小;相同条件下与普通混凝土梁相比,再生混凝土梁的挠度和最大裂缝宽度大,最大裂缝深度小;试验和理论分析表明,现行规范公式适用于计算再生混凝土梁的极限弯矩,而其开裂弯矩的计算则需要修正。

Flexural property test with three recycled concrete beams featured with recycled coarse aggregate replacement rate of 0,30% and 75 % respectively, was carried out to study the recycled concrete flexural deformation properties and damage characteristics. The results showed that： Recycled concrete reinforced beam failure process and failure mode was basically the same with common reinforced concrete beams; Normal section average strain to the as- sumption of plane section; Recycled concrete beam cracking moment, yield and ultimate mo- ment with recycled coarse aggregate replacement rate decreased; Under same conditions as compared with normal concrete beams ,the recycled concrete beam deflection and the width of crack was larger, the depth of crack was smaller. The results indicated that the formula sug- gested by present code can only be applied to the ultimate moment of recycled beam, but not suitable for cracking moment.