海工混凝土的氯离子扩散性与寿命评估

通过现场海洋曝露试验和实验室海水浸泡试验,采取分层取样和化学分析方法,应用氯离子三维扩散理论,研究了普通混凝土和高性能混凝土在海洋大气区、潮汐区、水下区和实验室海水浸泡下的C1-扩散系数变化规律.结果表明,混凝土的C1-一扩散系数随着曝露时间的增加而降低,高性能混凝土的抗C1-扩散性优于普通混凝土.在Khatri计算模型的基础上,提出了考虑劣化效应系数的海工混凝土使用寿命计算模型.该模型计算结果与Clear经验模型基本吻合,解决了Khatri计算模型结果与实际寿命不相符的问题.

Life Assessment and Chloride Ion Diffusivity of Marine Concrete

Through field exposure test in the ocean and sea-water immersion test in the laboratory,taking methods of stratified sampling and chemical analysis,permeability of chloride for ordinary Portland cement concrete(OPC)and high performance concrete(HPC)in marine atmospheric zone,tidal zone,submerged zone and laboratory seawater iS examined on the basis of three-dimensional chloride diffusion theory.The results show that chloride diffusion coefficient(D_t)increases with the decrease of exposure time;the chlo-ride ion diffusivity of HPC is less than that of OPC.On the basis of Khatri's model,a new model for cal-culating service life of marine concrete is proposed.Influencing factors of degradation index(K) of concrete is taken into consideration.The results from the new model is in good agreement with those of Clear's ex-perimental model.