关于混凝土保护层厚度合理性的相关研究

Sesearch on the Rationality of Concrete Cover Values

对欧美及我国规范中保护层厚度相关要求作了对比,并分别按照碳化寿命准则、锈胀开裂寿命准则对保护层厚度合理值进行了计算。结果表明,我国规范中保护层厚度取值与锈胀开裂准则计算值接近,与欧美规范值相比偏小,在恶劣环境下尤其明显,最大差值达到30%以上,并且规范中未考虑施工允许偏差的影响;按碳化准则计算时,现行规范要求的保护层厚度值远达不到相应耐久年限的可靠指标要求。在设计和施工阶段,关于保护层厚度的要求应进一步加强。这将使结构更安全耐久,并减少使用期内的维护及大修次数,降低能耗。

The comparison of concrete cover thickness requirements in European and American and Chinese codes was carried out,and the thickness of the concrete cover was calculated according to the carbonization life criterion and the corrosion cracking life criterion,respectively.The results show that the thickness of the concrete cover in Chinese specifications is close to the calculated value of the rust expansion criterion,and it’s small compared with the European and American normative values,especially in harsh environments,the maximum difference is more than 30%,and the influence of construction tolerance is not considered in the specification.When calculated according to the carbonization criteria,the thickness of the concrete cover required by the current specification is far from the reliable index requirement for the corresponding endurance period.The requirements for the thickness of the concrete cover should be further strengthened during the design and construction phases.This will make the structure safer and more durable,and reduce the number of maintenance and overhauls during the use period,reducing energy consumption.