受冻融混凝土表面处理后水分侵入机理研究  

Study on Water Migration Mechanism of Frozen-thawed Concrete Surface Treated with Silane Gel

作　　者：朱方之[1] 王鹏刚[2] 赵铁军[2] 郑文新[1] 

机构地区：[1]宿迁学院,宿迁223800 [2]青岛理工大学,青岛266033

出　　处：《硅酸盐通报》2014年第8期2038-2042,2046,共6页Bulletin of the Chinese Ceramic Society

基　　金：江苏省高校自然科学研究项目(13KJB570003);青岛市基础研究-联合基金计划项目(13-1-4-115-jch)

摘　　要：采用硅烷凝胶对冻融损伤混凝土进行表面处理,通过毛细吸水和压汞试验技术研究表面处理前后的受冻融混凝土吸水性能和微观孔结构,并对水分侵入机理进行分析。结果表明:随着冻融循环次数的增加,混凝土毛细吸收系数和孔隙率成倍数提高。在吸水初期36 h,硅烷凝胶用量和冻融损伤度对毛细吸水影响不明显,后期差异越来越大。受冻融混凝土表层孔结构劣化导致的憎水层致密性差,使得外部液态水从"水汽传输"逐步过渡到与内部非憎水区的凝结水形成"水路传输",是冻融损伤混凝土表面防水过早失效的根本原因。Frozen-thawed concrete specimens were surface impregnated with silane gel, then water absorption property, micro pore structure and water migration mechanism of frozen-thawed concrete before and after surface treatment were investigated through water absorption test and MIP test. Results indicate that the coefficient of capillary absorption and the porosity increase remarkably with the number of freeze- thaw cycles. During the initial 36 h of capillary absorption, the influence of amount of silane gel and damage degree of concrete is not obvious. But with the increase of duration, the influence will be lager and lager. Because of the degradation of micro structure of the skin layer on the frozen-thawed concrete, the compactness of the hydrophobic layer becomes loosen. This will lead to the change of water migration mechanism from ＂vapor transmission＂ into ＂water transfer＂. So it will be the fundamental reason for the early failure of water repellent treatment of concrete under frost environment.

关 键 词：冻融损伤 硅烷处理 毛细吸水 侵入机理 

分 类 号：TU528[建筑科学—建筑技术科学]