半浸泡干湿循环下混凝土硫酸盐腐蚀性能研究

关键字：半浸泡,硫酸盐侵蚀,浸泡区,干湿交替区,水胶比

[1.山西大学 土木工程系，山西 太原  030013；2.中国矿业大学（北京） 力学与建筑工程学院，北京  100083；3.国网山西省电力公司，山西 太原  030001]

    摘要：研究了水胶比和硅灰掺量对半浸泡干湿循环混凝土抗压强度的影响，并用SEM对浸泡区与干湿交替区的微观结构进行分析。结果表明：硅灰的掺入有利于混凝土28 d抗压强度的提高，较大的硅灰掺量应当配合较大的水胶比；掺硅灰的混凝土强度优势在干湿循环后期逐步体现，并且掺量在10%～15%效果较优；半浸泡干湿循环试件的浸泡区局部发生化学侵蚀，生成钙矾石，干湿交替区发生化学物理综合性侵蚀，生成石膏和芒硝，干湿交替区域的腐蚀更严重。
    关键词：半浸泡；硫酸盐侵蚀；浸泡区；干湿交替区；水胶比；硅灰
    中图分类号：TU528.33        文献标识码：A        文章编号：1001-702X（2017）04-0087-04

Study on the corrosion performance of concrete under wetting-drying sulfate partial soaking attack
LIU Jinyan1，2，GONG Tianzhen1，LI Qiang3
[1.Department of Civil Engineering，Shanxi University，Taiyuan 030013，China；2.School of Mechanics and Civil Engineering，China University of Mining & Technology（Beijing），Beijing 100083，China；3.State Grid Shanxi Electric Power Company，Taiyuan 030001，China]

    Abstract：The influence of water binder ratio and silica fume content on the compressive strength of concrete under wetting-drying sulfate partial soaking attack was studied， and the SEM was used to analyze the microstructure of the immersion zone and the dry-wet cycling zone. The results show that，the addition of silica fume increased the 28 d compressive strength of concrete，and larger silica fume content should be matched with larger water binder ratio；the strength superiority of concrete with silica fume is gradually revealed in the later period of dry-wet cycles，and the optimal amount of silica fume was 10%～15%；chemical erosion with ettringite corrosion product occurred in local area of immersion zone，while chemical and physical comprehensive erosion with gypsum and mirabilite corrosion product occurred in the dry-wet cycling zone，and the latter is more serious.
    Key words：partial soaking，sulfate attack，the immersion zone，the dry-wet cycling zone，water binder ratio，silica