底部双排配筋单孔空心预制梁力学性能试验研究

Experimental study on mechanical properties of bottom double row reinforced single-hole hollow prefabricated beam

为了研究新型装配式单孔空心预制梁的抗弯承载力和变形性能,并提高其工作性能。试验共设计并制作了3根单孔空心预制梁和1根实心预制梁,通过试验和理论计算相结合的分析手段,重点研究单孔空心预制梁和实心预制梁的破坏机理、裂缝发展、荷载-挠度曲线、变形性能及抗弯承载力等。结果表明:单孔空心预制梁与普通实心预制梁的破坏特征相似,且其裂缝分布较均匀、间距小,延性好;在相同荷载作用下,单孔空心预制梁挠度大于实心预制梁,其整体受力变形性能相对优越。提出了截面有效面积等效法和混凝土轴心抗压强度等效法2种计算方法,通过对比分析发现,混凝土轴心抗压强度等效法计算值误差仅为0.82%,满足工程要求,而且单孔空心预制梁与实心梁相比还可节约材料8.72%。因此,单孔空心预制梁具有良好的应用前景。

In order to enhance the working performance of the new prefabricated single-hole hollow prefabricated beam,the flexural bearing capacity and deformation performance were studied.Three single-hole hollow prefabricated beams and one solid prefabricated beam were designed and fabricated in the experiment.The failure mechanism,crack development,load-deflection curve,deformation performance and flexural capacity of the single-hole hollow prefabricated beams and solid prefabricated beams were studied by means of the analysis method combined with theoretical calculation.The results show that the failure characteristics of single-hole hollow prefabricated beams are similar to those of ordinary solid prefabricated beams,but the crack distribution is relatively uniform,the spacing is small,and the ductility is good.Under the same load,the deflection of single-hole hollow prefabricated beam is greater than that of solid prefabricated beam,and the overall deformation performance is relatively superior.Two methods for calculating the effective area of the section and the compressive strength of the concrete axis are proposed.Through comparative analysis,it is found that the error of calculating the compressive strength of the concrete axis is only 0.82%,which meets the engineering requirements,and 8.72%of materials can be saved compared with solid beams.Therefore,this kind of beam has a good application prospect.