纳米TiO2对有机涂层混凝土抗氯盐侵蚀性能的影响

Effect of Nano-TiO2 on the Chloride Resistance of Concrete with Polymer Coatings

为获得纳米TiO2对有机涂层混凝土抗氯盐侵蚀性能的影响规律,以氯化橡胶、环氧树脂、聚氨酯3种有机成膜涂料为基础,配制纳米TiO2改性有机成膜复合涂料,并对制作的涂层混凝土试件进行氯盐溶液长期浸泡、紫外光辐照加速老化、氯离子电通量和扫描电镜实验.研究结果表明:纳米TiO2颗粒的添加能够填充漆膜的微观孔隙,减少漆膜中的微观缺陷,增大漆膜的致密性,从而提高涂层混凝土的抗氯离子侵蚀能力,改善幅度达72%~93%;纳米TiO2颗粒的添加能够增大涂层对紫外线的吸收和屏蔽作用,从而减小紫外光辐照对有机涂层的老化作用,提高涂层老化后的残余抗氯盐侵蚀能力,改善幅度达34%~44%.

To investigate the effect of nano-TiO2 on the chloride resistance of concrete with polymer coatings,nano-TiO2 modified composite paints were produced based on chlorinated rubber,epoxy resin and polyurethane.Then,coated concrete specimens were fabricated and subjected to long-term immersion in chloride solution,accelerated aging by ultraviolet irradiation,Coulomb electric flux and SEM experiments.The results indicated that the addition of nano-TiO2 particles can fill the micro-pores in the coating film,reduce coatings'micro-defects,and increase coating film's density.As a result,it can effectively improve the chloride resistance of concrete with such coatings,and the improvements reached by 72%~93%.At the same time,nano-TiO2 particles can also increase the absorption and shielding capability of a coating against ultraviolet light,and therefore reduce the aging effects of ultraviolet irradiation on organic coatings.Hence,the residual chloride resistance of a coating after aging was substantially improved,and the improvements reached by 34%~44%.