骨料粒径对无腹筋梁抗剪性能影响的试验研究

Experimental Study on Aggregate Size Role in Shear Strength of Reinforced Concrete Beams without Shear Reinforcement

为研究骨料粒径对无腹筋梁抗剪性能的影响,完成了集中荷载作用下16根无腹筋钢筋混凝土简支梁的抗剪性能试验.主要试验变量为最大骨料粒径和剪跨比.根据试验结果分析试验梁的破坏形态、斜截面抗剪承载力、荷载-位移曲线、裂缝面间的相对位移等内容,比较试验数据与已有无腹筋梁受剪试验结果,并将试验结果与GB 50010-2010,ACI318-08,EC 2-02和CSA 23.3-04等规范的预测结果进行比较.研究结果表明,骨料咬合作用是无腹筋梁剪切破坏的重要传力机制,抗剪设计方法应建立在充分考虑骨料咬合作用对钢筋混凝土梁抗剪性能影响的基础上.

In order to investigate the influence of the maximum aggregate size on the shear behavior of beams without shear reinforcement,16 reinforced concrete beams subjected to concentrated loading were tested.The main parameters are the maximum aggregate size and span-to-depth ratio.Based on the test results,the failure mode,the ultimate shear capacity,the load-middle deflection curves and the relative displacement between crack lips were analyzed.Combined with a comparison of the test data and those published in the literature,the tested shear capacity was compared with the predicted value of GB 50010-2010,ACI 318-08,EC 2-02 and CSA 23.3-04.It can be concluded that the aggregate interlock is the main mechanism of shear transfer in beams without shear reinforcement,and that shear design methods should be established on the basis of accounting the critical influence of aggregate interlock on the beamshear behavior of reinforced concrete members.