锈蚀钢筋混凝土梁斜截面受剪承载力计算

侵蚀环境下混凝土结构中钢筋易于发生绣蚀,造成混凝土、钢筋等材料力学性能劣化、界面粘结性能退化以及构件截面几何尺寸变化,导致服役期混凝土结构承载能力下降,严重影响结构的安全使用。以锈蚀钢筋混凝土简支梁斜截面为研究对象,在分析锈蚀对钢筋混凝土梁抗剪强度影响的基础上,提出了集中荷载作用下锈蚀钢筋混凝土梁抗剪强度的计算模型,应用拉压杆模型对锈蚀梁的受剪承载力进行了计算,并通过75根锈蚀梁的试验结果对建议计算模型进行验证。结果表明:锈蚀钢筋混凝土梁受剪承载力试验值与计算值之比的平均值为1.226,方差为0.028,试验值与理论值的相关性系数为0.968,建议模型抗剪强度预测值与试验结果吻合较好。

Prediction of Shear Bearing Capacity of Corroded Reinforced Concrete Beams

The reinforcing bars in concrete structures are prone to corrosion under aggressive environments attack, which causes degradation of mechanical properties of structural materials such as concrete and reinforcing bar, also leads to weakness of bond performance between concrete and surrounding reinforcement together with decrease of dimension of corroded concrete members. Therefore, the corrosion of reinforcing bar greatly threatens the safety of concrete structures. By selecting corroded reinforced simply supported concrete beams as research object, an analysis model of shear baring capacity of corroded reinforced concrete beams under concentrated loads was put forward on the basis of the analysis of the effect of steel corrosion on shear baring capacity of corroded reinforced concrete beams, particularly the shear strength of corroded beam was calculated by using strut-and-tie model. The suggested analytical model was verified by using 75 corroded reinforced concrete beams. It is believed that good agreement between test results and prediction results for shear strength is achieved with an average ratio of test results to predicted results of 1.226 and a variance of 0.028 and a correlation coefficient of 0.968 between test results and predicted results.