关于结构实体钢筋保护层厚度检测结果代表性、检测结论科学准确性的探讨

Discussion on the Representativeness of Test Results of the Thickness of the Reinforced Protective Layer of the Structural Entity and the Scientific Accuracy of Test Conclusions

混凝土结构子分部工程施工质量验收中规定结构实体钢筋保护层检测结果应符合《混凝土结构工程施工质量验收规范》GB50204—2015附录E的要求,但该附录第E.0.2条“对每根钢筋,应选择有代表性的不同部位量测3点取平均值”、第E.0.5条第3款“每次抽样检测结果中不合格点的最大偏差均不应大于本规范附录E.0.4条规定允许偏差的1.5倍”,在实施过程中存在不同理解,从而出现钢筋保护层厚度检测结论误判,给结构构件耐久性、握裹层混凝土对受力筋的锚固、承载力造成了严重隐患。该文就如何确保检测结果代表性、检测结论科学准确性进行了分析,并提出了相应的方法,可供行业技术人员参考。

It is stipulated that the test results of the reinforcement protective layer of the structural entity in the construction quality acceptance of a concrete structure sub-division project should meet the requirements of Appendix E of Code for Acceptance of Constructional Quality of Concrete Structures GB50204—2015.However,under Appendix E,there are different understandings in the implementation process as to Article E.0.2 that for each steel bar,3 different representative parts should be selected to test and average the results,and Item 3 of Article E.0.5 that specification states that the maximum deviation of nonconforming points in each sampling test result shall not be greater than 1.5 times of the allowable deviation specified in Article E.0.4.Owing to these misunderstandings,a misjudgment emerges on the thickness detection conclusion of the protective layer of the steel bar,causing serious potential dangers to the durability of the structural members,and the anchorage and bearing capacity of the wrapped concrete to the the stressed bars.The representativeness of the test results and the scientific accuracy of the test conclusions are analyzed in this paper,with corresponding methods presented for the reference of technical personnel in this industry.