淡水壳菜对大型输水工程混凝土表面侵蚀及防护措施研究

Study on Erosion and Protection Measures of Concrete Surface in the Large Water Delivery Project by Limnoperna Fortunei

输水工程混凝土结构服役过程中常遭受生物侵蚀,侵蚀机理研究以及如何防护问题引起关注,侵蚀防护措施中要综合考虑防除效果、环保性、可操作性及成本问题,但可应用实际工程的很少,有关混凝土生物污损问题目前无法有效解决。鉴于华南地区某大型输水工程存在淡水壳菜侵蚀的问题,研究了淡水壳菜对混凝土面的侵蚀作用,对比分析了多种涂料涂覆方法的效果,确定了工程处理措施。研究表明,淡水壳菜形成的污损体系共同对混凝土表面产生侵蚀破坏,淡水壳菜通过生命活动,分泌有机酸对混凝土中的Ca(OH)_2和C-S-H凝胶进行腐蚀;通过呼吸产生CO_2使混凝土碳化,导致混凝土芯样的pH值下降。结合已建工程特点,采用混凝土面布设涂层的措施进行防护,现场涂覆试验和挂板试验,结果表明:BX涂料具有很好的防护效果。

The concrete structure of water conveyance project is often subjected to biological erosion during service.The study of erosion mechanism and how to protect it is concerned.The effect of protection,environmental protection,operability and cost should be considered comprehensively in the process of erosion protection,so few practical engineering works can be applied,and the problem of biological fouling of concrete cannot be effectively solved at present.In view of the problem of erosion of freshwater mussels in Southern China area of a large-scale water diversion project,studied the erosion of freshwater mussels on the concrete surface,analyzed various coating methods to determine the effect of engineering measures.The research shows that the formation of fouling system of common freshwater mussels cause erosion damage to the concrete surface,freshwater mussels through life activities,the secretion of organic acids on concrete in Ca(OH)2 and C-S-H gel corrosion;CO 2 the concrete carbonation caused by breathing,concrete core samples of pH decreased.Combined with the characteristics of the built projects,the measures of coating the concrete surface are applied to protect.The field coating test and the hanging plate test shows that the BX coating has good protective effect.