钢纤维再生混凝土T形梁抗剪性能试验研究

Experimental study on shear performance of steel fiber reinforced recycled concrete T-shaped beams

为研究再生混凝土T形梁的抗剪性能,以再生骨料取代率、钢纤维体积率、配箍率和剪跨比为参数设计了5个再生混凝土T形梁。通过单调加载试验,对再生混凝土T形梁的破坏特征、承载力、变形能力以及钢筋应变结果进行了研究,并基于现有规范和试验数据对各试件的峰值承载力计算方法进行了研究。结果表明,梁的抗剪承载力受再生粗骨料的影响较小,但再生粗骨料的使用会降低梁的刚度及变形能力,使梁的剪切脆性破坏特征更为明显;掺加钢纤维或增大配箍率均可以提高梁的承载力和变形能力,有效改善再生混凝土梁的剪切脆性破坏情况;试件的承载能力随剪跨比的减小而增大,但其变形能力随之降低;修正方法得到的抗剪承载力计算值与试验值相比误差较小,可为再生混凝土梁的抗剪设计提供参考。

In order to study the shear performance of reinforced recycled concrete T-shaped beams, five recycled concrete T-shaped beams were designed with the parameters of recycled aggregate replacement rate, steel fiber volume rate, stirrup rate and shear span ratio. Through the monotonic loading test, the failure characteristics, bearing capacity, deformation capacity and steel strain results of recycled concrete T-shaped beams were studied, and the peak bearing capacity calculation method of each specimen was studied based on the existing specifications and test data. The results show that the shear resistance of the beam is less affected by recycled coarse aggregate, but the use of recycled coarse aggregate will reduce the stiffness and deformation capacity of the beam, making the shear brittle failure characteristics of the beam more obvious. Adding steel fiber or increasing the hoop ratio can improve the bearing capacity and deformation capacity of the beam, and effectively improve the shear brittle failure of recycled concrete beams. Reducing the shear span can significantly increase the load-bearing capacity of the specimen, but its deformation capacity decreases accordingly. Compared with the experimental value, the calculated value of the shear capacity obtained by the correction method has a smaller error, which can provide a reference for the shear design of recycled concrete beams.