不同叠合方式超高性能混凝土叠合板受弯性能试验研究

Experimental study on flexural behavior of UHPC aminated plates with different superimposed surfaces

为了探讨超高性能混凝土(UHPC)叠合板的受弯性能,对1块UHPC整浇板和3块不同叠合方式的UHPC叠合板试件进行弯曲试验,对试件的承载力、挠度、混凝土应变及钢筋应变展开分析,并进行平截面假定验证。研究表明,UHPC叠合板在对称荷载作用下试件纯弯段满足平截面假定;UHPC叠合板的混凝土应变滞后现象和钢筋应力超前现象较普通混凝土叠合板的小,整体工作性能良好,人工粗糙面即能满足叠合面的抗剪要求,设置桁架钢筋和马镫钢筋可有效提高UHPC叠合板的弯曲刚度及承载力,且具有较好的受弯延性和弹性恢复能力;对于叠合面连接的抗剪效果,桁架钢筋优于马镫钢筋。最后提出了UHPC叠合板受弯承载力计算的建议公式。

In order to study the bending resistance of UHPC laminated plate, the experimental research on one block cast-in-place plate and three different laminated composite panels was carried out. The bearing capacity, strain of concrete, deflection, and strain of shear reinforcement were analyzed. The plane section assumption of test plates was verified. The research results show that the concrete strain lag phenomenon and the reinforcement stress advance phenomenon of UHPC composite slab are smaller than those of ordinary concrete composite slab.The overall performance of the composite plate is good, and the artificial rough surface can ensure the shear strength of the composite surface. The truss reinforcement and stirrup reinforcement can effectively improve the ultimate bearing capacity, overall performance and stiffness of the UHPC laminated plate, and have a good ductility and resilience. Truss reinforcement is better than stirrup truss in terms of enhancing shear strength and connection effect.Finally, a formula for calculating the flexural capacity of UHPC composite plates was presented.