再生砖混骨料混凝土梁受弯性能

建造于20世纪的老旧房屋拆除垃圾往往含有大量的红砖块。红砖的各项性能与废混凝土有较大区别，但目前建筑固废处理工艺不能较好地分离红砖骨料。为高效合理利用含有大量红砖的再生砖混骨料，对强度等级分别为C25、C30和C35的3根天然骨料混凝土梁和3根再生砖混骨料混凝土梁进行受弯性能试验研究，分析再生砖混骨料混凝土梁相比于同强度的天然骨料混凝土梁在受力过程、破坏特征、变形能力与承载力等方面的差异。试验结果表明：再生砖混骨料混凝土梁在加载至破坏过程中，具有同天然骨料混凝土梁相似的受力阶段，且同样符合平截面假定。但相比同强度的天然骨料混凝土梁，再生砖混骨料混凝土梁极限承载能力略小，在加载过程中梁表面裂缝更易产生与发展，刚度下降更显著，变形更大，且从屈服到破坏产生的变形较小，延性较差。

Flexural performance of recycled aggregate concrete beams containing waste concrete and bricks

The recycled aggregate made from the demolition of old houses in the last century contains a lot of red bricks. There are obvious differences between red bricks and waste concrete in properties. However, the current treatment process of construction solid waste cannot efficiently separate brick aggregates. To provide a reasonable solution for the efficient and rational use of recycled aggregate concrete containing waste concrete and red bricks, three beams made with natural aggregate concrete (NAC) and three beams made with recycled aggregate concrete (RAC) containing waste concrete and bricks with strengths of C25, C30 and C35 were designed. Bending tests were carried out on six beams to analyze the differences in the process of stress, failure characteristics, deformation capacity, ductility and bearing capacity between RAC beams and NAC beams of the same strength. The results show that in the process of loading to failure, the RAC beams show three stress stages similar to the NAC beams, which also accords with the plane section assumption. However, compared with the NAC beams of the same strength, the ultimate bearing capacity of the RAC beams is slightly smaller, the loading cracks on the surface of beams are more likely to generate and develop during the loading process, the stiffness decreases more significantly, the deformation is greater, the deformation developed from yield to failure is smaller, and the ductility is poor.