钢纤维轻骨料混凝土叠浇双向板抗冲切试验研究

Experimental study on punching shear resistance of SFRLAC superposed two-way slabs

介绍了8块钢纤维轻骨料混凝土叠浇双向板的抗冲切试验结果,叠浇双向板的冲切受拉区浇筑钢纤维轻骨料混凝土、受压区浇筑普通混凝土,板四边简支,采用板中心柱头加载方式。主要变化参数为钢纤维轻骨料混凝土叠浇层的厚度,占板厚的比例为0、0.5、0.6和0.7。试验测得了板在各级荷载下的挠度、钢筋和混凝土应变、裂缝分布及开裂、钢筋屈服和极限荷载。结果表明:钢纤维轻骨料混凝土叠浇板的抗冲切承载力显著提高,抗冲切变形能力明显增强,冲切受拉面裂缝分布呈现出多条数细密化发展形态,板破坏时的延性有所增加。

Test results of eight steel fiber reinforced lightweight aggregate concrete superposed two-way slabs were introduced.The slabs comprise the steel fiber reinforced lightweight aggregate concrete in the tensile region and the ordinary concrete in the compressive region under punching shear,which were simply supported under the load transferred from the top of central column.The main parameter was the superposed thickness of steel fiber reinforced lightweight aggregate concrete layer which was the 0,0.5,0.6 and 0.7 times of the slab thickness.The test results included the deflection at slab center,the strains of reinforcement and concrete,the distribution of cracks as well as the loads corresponding to concrete cracking,reinforcement yield and ultimate state.It could be concluded that the punching shear resistance of steel fiber reinforced lightweight aggregate concrete superposed two-way slab was increased remarkably,the ability to resist the punching shear deformation was enhanced obviously,many fine cracks distributed on the tensile surface and the ductility at failure state increased to a certain extent.