混凝土局压承载力计算方法深化研究

为探究混凝土达到局部受压承载力时间接钢筋能否屈服,间接钢筋不屈服时拉应力如何取值,以及网格式间接钢筋在楔形体外如何实现合理锚固等问题,完成了18个配置螺旋式间接钢筋和18个配置网格式间接钢筋的混凝土试件的局压试验。试验结果表明:当混凝土发生局压破坏时,局压影响区范围内间接钢筋存在达不到屈服的现象;基于试验结果,获得了不同强度等级热轧钢筋(HPB300、HRB400、HRB500、HRB600)配置的螺旋式间接钢筋和网格式间接钢筋屈服所对应的间接钢筋体积配筋率;建立了发生局压破坏时未屈服的网格式间接钢筋与楔形体外侧面相交处拉应力的计算方法。

In-depth study on calculation method of local bearing capacity of concrete

To investigate whether the indirect steel bar is capable of yielding when the concrete reaches local bearing capacity, the calculation method of tensile stress when the indirect steel bar could not yield, and the possibility of reasonable anchoring of meshed indirect steel bar outside the wedge, 18 specimens reinforced with spiral indirect steel bars and 18 with meshed indirect steel bars were experimentally evaluated, subjected to local compression forces. Results show that when the concrete reached the ultimate load, non-yielding occurred in the indirect steel bars in the area affected by the local pressure. Based on the test results, the volumetric ratios of indirect steel bars corresponding to the yielding of the spiral and meshed indirect steel bars for hot-rolled steel bars with different strength grades (HPB300, HRB400, HRB500, HRB600) were obtained. A calculation method of the tensile stress at the intersection of the meshed indirect steel bar and the outer side of the wedge was established for the situation that the meshed indirect steel bar does not yield under local pressure.