肖杰　屈文俊　朱鹏

摘要：为比较不同粗细骨料组合对混凝土耐硫酸腐蚀性能的影响，对水灰比为0.45、尺寸为100×200的4种骨料组合（青石+黄砂，青石+大理砂，大理石+黄砂，大理石+大理砂）混凝土试件进行耐硫酸加速腐蚀试验。将混凝土试件浸泡于pH值为0.95左右的硫酸溶液中进行为期194 d的12次跟踪监测，根据检测数据计算得到了混凝土的腐蚀深度，按线性方程斜率从大到小对4种骨料组合混凝土硫酸腐蚀速率进行了排序。结果表明：含有大理石或大理砂骨料的混凝土比含青石和黄砂骨料的混凝土耐硫酸腐蚀性能高；腐蚀层受扰动情况下，腐蚀深度与腐蚀时间呈线性关系；大理石细骨料比大理石粗骨料更有利于减小腐蚀深度。

关键词：钙质骨料；硅质骨料；硫酸腐蚀；混凝土；腐蚀深度

中图分类号：TU528.01文献标志码：A

Abstract： In order to compare the impact of fine and coarse aggregates on concrete sulfuric acid resistance， accelerated corrosion experiment was conducted with four types of aggregate concretes composed of coarse and fine aggregates （gravel and river sand， gravel and marble sand， marble stone and river sand， marble stone and marble sand） and same water cement ratio of 0.45 and 100×200. The concrete specimens were kept in sulfuric acid solution with pH value range around 0.95， and 12 times continuous monitoring tests were carried in 194 d. The corrosion depth was calculated based on the monitoring data. The corrosion rates of the four types of concretes were sorted in descending by the slope. The results show that concrete with marble aggregates rich in calcium carbonate has better performance in sulfuric acid solution than that with inert aggregates （gravel and river sand）.Corrosion depth is linear with corrosion time when concrete sulfuric acid corrosion layer is interrupted. Moreover， the marble fine aggregate plays more important role on reducing concrete sulfuric acid corrosion depth than marble coarse aggregate.

Key words： calcareous aggregate； siliceous aggregate； sulfuric acid attack； concrete； corrosion depth

0引言

由于混凝土呈碱性，所以在酸性环境中容易受到侵蚀，其具有的良好耐久性也将受到很大的削弱。在城市和工业生产区，酸性环境普遍存在。环境中分布最广泛的酸是硫酸。酸雨[1]、硫铁矿山废水[2]中主要含有硫酸。污水管道的生活污水中富含蛋白质等有机物，在细菌的作用下，其中的含硫物质将转化为硫酸，最不利的情况下，混凝土表面的pH值能降低到1[3]。据报道在美国每年对酸腐蚀污水管道进行维修的费用达到250亿美元，甚至比每年建造新污水管道的预算费用210亿美元还要高[4]。因此混凝土耐酸腐蚀研究日益受到重视。Zivica[5]提出了在酸性环境下表征混凝土或砂浆性能的4类指标参数，其中腐蚀深度对于确定腐蚀环境中混凝土结构构件的腐蚀裕量和保护层厚度有着重要意义。……