轻质混凝土组合墙板受弯性能试验与数值研究

Experimental and numerical study on flexural behavior of lightweight concrete composite wallboard

为了研究轻质混凝土组合墙板的受弯性能,提出一种以免烧核壳轻集料混凝土为内叶板材料的组合墙板并进行了试验研究;采用数值模拟软件对试验结果进行了模拟验证,选取保温层厚度、桁架筋间距、钢筋网格边长以及桁架筋直径进行参数化分析,并使用改进后的等效截面惯性矩法对试验结果以及模拟结果进行了对比分析。结果表明:该组合墙板的开裂荷载为10.18 kN·m,为典型受弯破坏,可满足实际使用;以开裂荷载设计组合墙板时,保温层厚度作为主要控制参数,增大厚度使得截面中性轴偏移,有效截面高度增加,从而使开裂荷载得以提升;以极限荷载设计组合墙板时,增加保温层厚度、桁架腹筋数量、桁架筋直径以及减小钢筋网格大小均能提升组合墙板的极限承载力;通过理论公式计算的开裂荷载与试验值及模拟值均较为吻合,与试验值相对误差为10.69%,与模拟值最大相对误差为9.26%。

In order to study the flexural behavior of lightweight concrete composite wallboard,a composite wallboard with unburned core-shell lightweight aggregate concrete as inner wythe was proposed,and the experimental research was conducted.The experimental results were verified through numerical simulation software,and the thickness of insulation layer,the spacing of truss bars,the side length of steel grid and the diameter of truss bars were selected for parametric analysis.The improved equivalent section moment of inertia method was used to compare and analyze the test and simulation results.The results show that the cracking load of composite wallboard is 10.18 kN·m,which is typical flexural failure and can meet the practical application.When the composite wallboard is designed with the cracking load,the thickness of insulation layer is used as the main control parameter.When the thickness is increased,it makes the neutral axis of section shift and the effective section height increase,so that the cracking load can be improved.When the composite wallboard is designed with ultimate load,the ultimate bearing capacity of the composite wallboard can be improved by increasing the thickness of insulation layer,the number of truss web bars,the diameter of truss bars and reducing the size of steel mesh.The cracking load calculated by the theoretical formula is in good agreement with the experimental and simulated values,and the relative error with the test value is 10.69%,and the maximum relative error with the simulated value is 9.26%.