Abstract: The concrete grade of strength in the present design code for concrete structures is a basic representative quantity for the various strengths of concrete used for design. It is also a criterion to evaluate the quality of concrete in the construction. Now the present code has got considerable changes in concrete grade of strength. In order to understand and put the present code into practice correctly, this paper has stated this variation by contracting the present with the former code and deduced the conversion relationship between the concrete grade of strength and the concrete mark of the former code, which is very useful for practical engineering.

Key words: concrete grade of strength, concrete mark of the former code

摘要： 现行钢筋混凝土结构设计规范中混凝土强度等级是设计用混凝土各种力学指标的基本代表值,也是施工验收中评定混凝土质量的标准,它较原规范作了较大的修改。为了正确理解和执行现行规范,本文采用对比的方式叙述了这种变化,并导出了对工程非常有用的混凝土强度等级与原规范混凝土标号之间的换算关系。

关键词: 混凝土强度等级, 混凝土标号