欧洲、美国规范混凝土结构裂缝控制方法及其与中国规范的对比研究

对欧洲、美国、中国混凝土结构设计规范的裂缝控制设计方法及其演变过程进行了系统梳理,并详细对比了各国现行规范中裂缝验算方法。比较发现:1)欧洲规范进行裂缝验算时考虑的因素最全,方法上也呈现出逐渐简化的趋势;现行规范中的验算方法,设计人员根据实际工程需要选用其一即可。2)美国规范认为混凝土构件裂缝大小存在一定随机性,很难通过计算掌握实际裂缝宽度。因此现行规范ACI 318-14中规定的最大钢筋间距限值,只考虑了受拉钢筋应力和混凝土保护层厚度;该方法简单,易于为工程采用。3)以圭亚那水处理厂混凝土结构为例,分别采用欧洲、美国和中国规范的计算公式验算该结构的裂缝宽度,结果表明各规范裂缝宽度验算结果相差不大,相比较我国规范要求更加严格。

Study on cracks control method in concrete structures in European and American codes and their comparisons with Chinese code

The crack control design method and its evolution process in European, American and Chinese design codes for the concrete structure were systematically summarized, and the crack checking methods in current code of each country were analyzed in detail. It is found that:1) European code considers the most comprehensive factors in crack checking, and the method is simplified gradually. In the current code, designers can choose one of the checking methods according to the actual needs of the project;2) American code indicates that the size of concrete cracks has some uncertainties and it is difficult to calculate the real crack width. Therefore, the maximum steel bar spacing limit stipulated in ACI 318-14 only takes into account the tensile stress of the steel bar and the concrete cover thickness. The method is easy to be used in engineering project;3) Taking the concrete structure of Guyana Water Treatment Plant as an example, the crack width of the structure is checked with the formula in European, American and Chinese codes respectively, and the results show that the checking results of crack width of each code are quite close, of which the Chinese codes is more stringent.