海洋大气环境下粉煤灰混凝土耐久性研究

海洋大气环境中的混凝土结构不仅要遭受盐雾腐蚀,同时还要受碳化影响。在盐雾腐蚀及碳化双重作用下,混凝土结构极易发生钢筋锈蚀。本文开展了盐雾腐蚀及碳化双重作用下的氯离子侵蚀试验研究。研究结果表明:当粉煤灰掺量不超过30%时,粉煤灰混凝土的抗氯离子侵蚀能力随粉煤灰掺量的增加而提高。碳化反应不仅造成混凝土孔隙溶液pH值下降,同时粗化了混凝土的孔隙,引起混凝土微观结构重分布,破坏原有的过滤机制,使得侵蚀环境中的氯离子更容易渗入。采用修正后的Fick第二扩散定律解析解对盐雾环境下混凝土中的氯离子浓度进行非线性拟合,具有良好的相关性。

Research on the Durability of Fly Ash Concrete in Marine Atmospheric Environment

The concrete structures in the marine atmospheric environment are subjected to coupling action of salt spray corrosion and carbonation,and the concrete structures in the marine atmospheric are more susceptible to reinforcement corrosion.In this paper,the durability test of the concrete subjected to the coupling action of the salt spray corrosion and carbonation was carried out.The results showed that when the fly ash less than 30%,the performance of resistance to chloride ion corrosion of the concrete will improve with the increasing of the fly ash.The carbonation caused the decrease of the pH value of the concrete pore solution.The concrete microstructure was redistributed,and the original filtering was destroyed,all of these make it easier for chloride ions to penetrate into concrete.The revised analytical solution of Fick’s second law of diffusion is suitable for the nonlinear fitting of the chloride ion concentration in concrete after the salt spray corrosion.