压剪作用下混凝土抗剪强度的试验研究

Experimental research on shear strength of concrete under compression and shear

混凝土构件的侧压力可以极大地提高其抗剪强度。但是,由于缺乏试验数据,这种效应在实际构件的抗剪设计以及数值模拟中常被忽略,导致其真实抗剪强度被低估。针对以上问题,本文给出了一种基于标准立方体试块的二维压剪试验方法,并对6种常用混凝土进行了加载试验,研究了不同标号、不同侧压力下混凝土的抗剪强度。基于试验结果,提出了一种能准确反映侧压力影响且形式简单的混凝土抗剪屈服面模型,并通过与其他方法的对比验证了其有效性。研究成果可为预应力混凝土构件的抗剪设计、数值模拟提供参考和依据,具有较强的理论和工程实用价值。

The pressure applied on concrete members can greatly improve the shear strength of concrete components.However,the influence is always neglected in practical designs and numerical analysis due to the lack of corresponding experimental data,which may lead to a serious underestimation of the shear strength of concrete under compression and shear.In this study,a 2-D compression-shear test strategy based on standard cubic specimens was proposed,and six kinds of concrete with different mix proportions were tested.Based on the tests results,a shear strength model was developed,in which the form was simple and the influence of the lateral pressure on the shear strength was considered.The effectiveness of the proposed model was identified by comparing existing methods.This study can provide reference and basis for shear design and numerical simulation of prestressed concrete members.