不同pH值下含铁矿物对硫酸侵蚀混凝土的影响研究

硫酸侵蚀为混凝土耐久性损伤的一个重要方面。在硫酸盐侵蚀过程中,含铁矿物等侵蚀产物不断形成,导致混凝土材料形成不同程度的腐蚀。为研究不同pH值环境下含铁矿物对混凝土结构腐蚀的影响,在实验室配置了pH值为2.0、3.0和4.0的稀硫酸溶液,结合不同洗刷作用方式来模拟酸雨环境,采用室内长期浸泡试验方法对混凝土试件进行不同程度腐蚀。用X射线能谱分析(EDS)现代测试技术分析得到腐蚀剩余物质Fe元素。结果表明:浸泡液的pH值对混凝土的腐蚀速度有一定的影响,当浸泡液的pH值小于3以后,硫酸对混凝土的腐蚀速度要考虑含铁矿物的影响;当大量的氢氧化铁参与反应时会消耗更多的H2SO4,腐蚀速度会有小幅度提升,在定期更换浸泡液并清洗试件表面的洗刷作用下更加明显,耗酸速度提升到了10倍。

Study on the Influence of Iron Ore on Sulfuric Acid Erosion Concrete Under Different pH Values

Sulfuric acid erosion is an important aspect of concrete durability damage.In the process of sulfate erosion,iron ore and other corrosion products are formed constantly,which leads to different degrees of corrosion of concrete.In order to study the influence of iron ore on the corrosion of concrete structure under different pH values,dilute sulfuric acid solutions of pH 2.0,3.0 and 4.0 were prepared in the laboratory.In combination with different ways of washing,acid rain environment was simulated.Long-term immersion test method was used in the laboratory to conduct different degrees of corrosion on concrete specimens.Fe element was obtained by X-ray energy spectrum analysis(EDS).The results showed that the pH value of the immersion solution had a certain influence on the corrosion rate of concrete.When the pH value of the immersion solution is less than 3,the influence of sulfuric acid on the corrosion rate of concrete should be considered.When a large amount of iron hydroxide was involved in the reaction,more H2SO4 will be consumed,and the corrosion rate will be slightly increased.Under the washing action of regularly changing the immersion solution and cleaning the surface of the specimen,the acid consumption rate will be increased to 10 times.