混凝土盐冻过程中的氯离子结合研究  

Chloride binding in concrete subjected to salt frost

作　　者：张磊 杨莉[2] 迟守慧 

机构地区：[1]青岛市政建设发展有限公司,山东青岛266071 [2]青岛理工大学土木学院,山东青岛266033

出　　处：《混凝土》2014年第4期17-19,23,共4页Concrete

基　　金：国家自然科学基金项目(51178230);铁道部科技研究计划(2008G031-41);山东省高校优秀团队基金

摘　　要：C30和C50引气混凝土在3.5%NaCl以及5%Na2SO4+3.5%NaCl溶液中自然浸泡或快速冻融循环,测试盐冻过程中混凝土的自由氯离子和总氯离子。结果表明:冻融循环不改变混凝土中氯离子传输规律,仍符合Fick第二扩散定律。腐蚀初期,浸泡环境下混凝土的氯离子浓度高于冻融环境,但随混凝土冻融损伤程度增加,趋势相反。氯盐环境下冻融,混凝土氯离子结合能力随龄期增加而下降;但在氯盐溶液中浸泡,混凝土氯离子结合能力随龄期增加而增加。复合盐溶液中硫酸根离子存在导致浸泡环境下混凝土氯离子结合能力随龄期增加而下降。The free chloride ion, total chloride ion distribution and calculated chloride binding capacity of concrete under attack of salt frost are systematically investigated.The compressive strength grade of air entrainment concrete is C30 and C50.The corrosion regimes are employed in this study： freeze-thaw cycles in 3.5% NaCl solution or in5%Na2SO4＋3.5%NaCl, and naturally immersion（ stored in corrosion solution with same time of freeze-thaw cycles ）.The experimental results show that the rule of chloride transported in concrete exposed to salt frost environment is followed from the Fick＇s 2nd law.The free and total chloride content of concrete stored in NaCl solution is higher than that of concrete exposed to salt frost in the initial corrosion stage, but the trend is exactly opposite in the later corrosion stage, espe-cially in serious frost damage period.When concrete frosted in NaCl solution,its chloride binding capacity decreases with corrosion time. And when concrete immersed into chloride solution, its chloride binding capacity increases with time.Additionally, sulfate ion in corrosion solution results in that the chloride binding capacity of concrete decreases with time.

关 键 词：混凝土 盐冻 传输 氯离子结合能力 

分 类 号：TU528.01[建筑科学—建筑技术科学]