附加措施对海洋环境下混凝土箱梁的寿命影响

Effects of Additional Measures on Service Life of Concrete Box Girder Exposed to Marine Environment

海洋环境下预应力混凝土箱梁,由于长期受到大气中氯盐的侵蚀作用,结构往往过早发生破坏,不能达到100年的耐久性设计要求。本文提出一系列技术措施:提高混凝土耐久性、增加保护层厚度、表面涂刷硅烷、采用不锈钢筋以及掺入阻锈剂,并基于可靠度理论,对各措施条件下预应力混凝土箱梁底板第一排主筋的锈蚀概率进行分析计算,然后进行分析比较,获得了预应力混凝土箱梁实现长寿命的可能技术途径及其效果,对实际工程设计具有直接的参考价值。

Due to the long-term chloride corrosion,the prestressed concrete box girder in the marine condition is often destroyed,so it cannot meet the requirement of the durability of 100 years.This paper puts forward a series of technical measures,namely,improving the durability of concrete,increasing the concrete cover thickness,painting silane in the surface,using the stainless steel,and adding the corrosion inhibitor.Moreover,based on the reliability theory,the corrosion probability of the main girder in the first rank of the prestressed concrete box girder by different measures is analyzed and compared.And then,some probable technical methods for the prestressed concrete box girder are obtained to meet the requirement of long service life,which can provide a valuable reference for the practical engineering.