保护层厚度对混凝土偏压构件性能影响分析

Analysis of the effect of protective layer thickness on the performance of RC eccentric compressive member

保护层是保证混凝土结构耐久性的重要屏障,虽然《混凝土结构设计规范》对最小保护层厚度有明确要求,但它又笼统地规定当保护层厚度大于40mm时需要采取防裂措施。当保护层厚度大于40mm时,究竟对结构性能会产生什么影响,至今并无充足的分析及试验研究阐明。以此作为研究出发点,分析了保护层厚度对构件耐久性寿命的影响,比较了加厚及普通保护层偏压构件的受力裂缝宽度变化,讨论了加厚保护层受压构件的承载力变化。分析结果表明:保护层厚度对构件的耐久寿命影响十分显著,而对受力裂缝宽度和承载力影响相对较小。

Protective layer is the important protection for the durability of RC structure.Though the smallest protective layer thickness is specified in the code for design of concrete,crack control measures should be taken when the protective layer is beyond 40mm.How much influence the protective layer will make to structure performance isn＇t fully clarified by analysis and experimentation.From this purport, the paper analyses the influence of extra-thick protective layer on the durability life, compares the change of maximum crack width tender the load between extra-thick protective layer and normal-thick protective layer and discusses the change of bearing capacity of extra-thick protective layer members. The results show： the protective layer thick can remarkably influence the durability life, but smally affect the maximum crack width under the load and the bearing capacity of eccentric compressive members.