环渤海湾海洋混凝土结构的长寿命研究与分析

Research and Analysis on Long Life of Marine Concrete Structure in Bohai Gulf

以环渤海湾海洋工程混凝土结构耐久性作为研究对象,根据多年来积累的实验室、海洋暴露站和工程实测数据,采用ChaDuraLife V1.0混凝土结构寿命预测模型与计算机软件,分析不同矿物掺合料掺量、水胶比对海洋混凝土结构服役寿命的影响规律.结果表明:降低水胶比,提高粉煤灰掺量和磨细矿渣掺量都能有效延长海洋混凝土结构的预期服役寿命.以环渤海湾海洋浪溅区混凝土结构为例,最长服役寿命所对应的海洋混凝土配合比最优参数是:粉煤灰和磨细矿渣掺量分别为20%、40%,水胶比为0.30,混凝土结构满足100、200、500 a寿命所需最小保护层厚度分别为60、75、120 mm.

Durability of concrete structures in marine engineering around Bohai Gulf was studied.According to the data obtained from a great series of experiments,the effect of mix design factors including different types of supplementary cementitious materials and different water‑binder ratios on the life span of concrete structure in marine environment was carefully studied with the help of ChaDuraLife V1.0 life prediction model and software,which is developed on the base of reliability and modified chloride diffusion theory.The results show that the reduction in the water‑binder ratio and the increment in content of fly ash and ground slag can effectively prolong the expected life span of marine concrete structures.Taking the concrete structure with the steel cover thickness of 75 mm in sea splash zone around Bohai Gulf as an example,the mix design which has the water‑binder ratio of 0.30,fly ash content of 20%and slag content of 40%is corresponding to the longest life span of marine concrete.In this area,the minimum thickness of concrete steel reinforcement in this mix design corresponds to the life span of 100,200,500 a are 60,75,120 mm respectively.