500MPa级钢筋再生混凝土梁受弯性能试验研究

通过对6根不同替代率、不同混凝土强度等级且配置500 MPa级钢筋的再生混凝土适筋梁进行受弯性能试验研究。重点分析了不同再生骨料替代率和混凝土强度等级对再生混凝土梁平截面假定适用性、承载能力、抗裂性能等方面的影响,探讨再生混凝土梁与普通混凝土在破坏形态等方面的异同。研究表明,除再生混凝土梁开裂荷载理论计算值比实测值大,不利于工程应用外,500 MPa级钢筋再生混凝土梁极限承载力没有降低,能够满足现行规范的要求,建议对再生混凝土梁开裂荷载理论计算值除以1.3进行调整。

An experimental study on the flexural property of recycled concrete beams with 500 MPa steel bars

Experimental study on the flexural property of recycled aggregate concrete beams with 500 MPa steel bars is carried out with different replacement ratios of recycled aggregate and concrete grades.The similarities and differences on the failure modes between the recycled aggregate concrete beams and the normal ones are discussed.For each replacement ratio of recycled aggregate and each concrete grade,the influence on the assumption of plane section,load-carrying capacity,crack resistance,etc.of recycled concrete beams is also analyzed.The results show that the ultimate bearing capacity of recycled concrete beams with 500 MPa steel bars is not reduced,which meets the requirements of the current code,but the calculated value of the cracking load is larger than the measured value,which is to the disadvantage of their engineering application.Accordingly,it is advised that the calculated cracking load of recycled concrete beams should be divided by 1.3 in practical application.