复合盐蚀环境下喷射混凝土离子分布规律及氯离子扩散系数  

Ions Distribution Regularity and Chloride Diffusion Coefficient of Shotcrete under the Environment of Compound Salt Attack

作　　者：袁斌[1] 牛荻涛[1,2,3] 王家滨[1] 

机构地区：[1]西安建筑科技大学土木工程学院,西安710055 [2]西部绿色建筑重点实验室协同创新中心,西安710055 [3]结构工程与抗震教育部重点实验室,西安710055

出　　处：《硅酸盐通报》2017年第6期1860-1867,共8页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(51278403);教育部创新团队发展计划(IRT13089)

摘　　要：通过分析(干湿循环+复合盐侵蚀)共同作用下普通混凝土、普通喷射混凝土和钢纤维喷射混凝土孔隙液中pH值、Cl^-、SO_4^(2-)和Ca^(2+)分布情况,研究了喷射混凝土离子分布规律和氯离子扩散系数。结果表明:各混凝土pH值和Ca^(2+)浓度随深度分布规律相似,均为表层最低并随深度增加而升高,且在同一深度随龄期增加而降低;普通混凝土表层Cl-浓度最高且扩散深度最大,钢纤维喷射混凝土的表层Cl-浓度最低和扩散深度最小;SO_4^(2-)在各混凝土内部的分布大致分为富集区、过渡区和稳定区三段;表面自由Cl-含量Cs为普通混凝土>普通喷射混凝土>钢纤维喷射混凝土,且随侵蚀龄期的增长而逐渐上升;混凝土的Cl-扩散系数D随侵蚀龄期的增长而降低,符合幂函数变化规律。The pore solution of pH value, Cl^- , SO4^2-4 and Ca^2＋ distribution situation of ordinary concrete, ordinary sboterete and steel fiber shotcrete are analyzed under the combined action of （wetting and drying cycles ＋ compound salt erosion） , the ions distribution regularity and chloride ion diffusion coefficient of shotcrete are investigated. The results show that the pH value and Ca^2＋ concentration distribution regularity with depth of each concretes are similar, and all lowest on surface, increase with depth increasing, and decrease with the age increasing in the same depth. The Cl^- concentration of ordinary concrete surface is the highest, and its diffusion depth is the lowest, but steel fiber shotcrete contrasting with ordinary concrete. The distribution of SO4^2- in the concrete can be divided into three segments, rich region, transition region and stable region. The Cs of ordinary concrete 〉 ordinary shotcrete 〉 steel fiber shotcrete, and increase gradually with the age increasing. The D reduced gradually with the age increasing, which is in accordance with the law of the variation of power function.

关 键 词：喷射混凝土 复合盐 共同作用 离子分布规律 氯离子扩散系数 

分 类 号：TU528.53[建筑科学—建筑技术科学]