目前在筋混凝土桥面板冲切破坏机理的研究中, 多数国家规范用冲切强度计算公式均未将保护层厚度作为计算参数。为揭示钢筋混凝土桥面板抗拉侧保护层厚度对其静力冲切强度的影响规律, 采用中国规范用公式、Matsui 公式及自行推导公式, 对16 块不同保护层厚度的钢筋混凝土板试件的理论强度进行计算, 通过比对3 个公式的计算结果与实验结果的差异, 分析了保护层厚度对混凝土板的作用机理, 并对自行前期推导的计算公式进行评价、完善, 提出新的采用保护层作用系数的计算方法。算例的比较结果表明, 新提出的钢筋混凝土板冲切强度计算公式适用范围较广且精度得以提高。
In the several codes and standard equations for the punching shear strength of reinforced concrete slabs, the cover thickness is not an influencing factor of the punching shear strength. 16 specimens of reinforced concrete slabs with various cover thicknesses are selected in the tests. The punching shear strength is found to increase with the increase of the cover thickness, in a nolinear way. The mechanism of the impact of the cover thickness on the concrete slab strength is analyzed based on a comparison between the calculation results and the test results, and finally, a new calculation method is proposed through the evaluation of the incipient theoretical equation. Test data are compared with the provisions of CCES, and with the proposed equation of Matsui, a simplified equation is proposed, which enjoys a better accuracy.
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