钢筋保护层厚度对裂缝及配筋的影响

基于耐久性及保证混凝土握裹层对钢筋的锚固作用,现行水运及水利工程钢筋混凝土结构设计规范对钢筋的最小保护层厚度均做了要求,但对最大保护层厚度未做限定。对于桩基梁板结构,为施工方便,设计中往往采取增大保护层厚度的方式来避免主筋在桩基周围截断并弯折。以现行规范为基础,结合工程实例分析后认为,混凝土最大保护层厚度的适宜取值区间为100~150 mm。本结论对今后类似工程,尤其是沿海高桩梁板码头的设计工作具有一定的借鉴作用。

Influence of concrete protective layer to reinforcement and concrete cracking

Based on the requirements of durability and bond strength of concrete,the present design codes for concrete hydraulic structures set the minimum thickness of concrete protective layers while give no requirements for the maximum protective layers.For board or beam structures with piles,to facilitate construction,increasing the protective layer is often applied to prevent the break off and bend of reinforcement when meeting with piles.Based on present standards,this paper analyzes the engineering example,and concludes that the optimal maximum protective layer over reinforcement is between 100mm and 150mm.The conclusion can be reference for future reinforcement design of port and waterway engineering works,especially the design of high pile wharf in the coastal area.