保护层厚度对钢筋混凝土结构裂缝宽度的影响  

Influence of cover thickness on transverse crack width of reinforced concrete structure

作　　者：邵剑萍 高明赞[2] 干伟忠[2] 

机构地区：[1]宁波市城建设计研究院有限公司,浙江宁波315012 [2]宁波工程学院混凝土结构耐久性研究所,浙江宁波315016

出　　处：《混凝土》2010年第11期21-24,27,共5页Concrete

基　　金：浙江省重点科技计划项目(2006C24008)

摘　　要：以两个钢筋混凝土结构受弯构件（分别为强度控制工况和裂缝控制工况）为例,根据国内现行规范分析了钢筋的混凝土保护层厚度对荷载作用下横向裂缝宽度的影响。结果表明：根据不同行业规范得到的同种工况下的横向裂缝宽度计算值存在较大差异,这个问题值得进一步研究并作出合理解释;混凝土结构横向裂缝宽度计算值一般随钢筋的保护层厚度的增大而增大;钢筋的混凝土保护层的加厚虽然会引起受拉区混凝土裂缝宽度的增大,但对整体结构耐久性而言利大于弊,不必为了控制裂缝宽度而忌用较厚（50~100mm）的保护层。Citing two examples of reinforced concrete flexural members（under strength control condition and crack control condition respectively）,this article,according to current national codes,analyzes the influence of concrete cover thickness of steel bar on transverse crack width under load.The results show that under the same conditions,there are substantial discrepancies among the calculated values of transverse crack widths obtained using different industry standards.This problem is worth further investigation and discussion;generally,the calculated values of reinforced concrete transverse crack widths increase as the concrete cover thickness increases.Although the increase the concrete cover thickness leads to the enlargement of crack widths of concrete in tension zone,its advantages outweigh the disadvantages in terms of durability of the whole structure.Therefore,thick concrete cover（50~100 mm） may not be avoided to limit the crack widths.

关 键 词：混凝土结构 混凝土保护层 横向裂缝 耐久性 现行规范 

分 类 号：TU528.01[建筑科学—建筑技术科学]