冻融后表层混凝土的孔结构劣化与损伤特性研究  

A Study on Deterioation of Pore Structure and Damage Property of Surface Concrete Caused by Freeze-Thaw Action

作　　者：朱方之[1,2] 赵铁军[3] 张鹏[3] 张连水[3] 

机构地区：[1]宿迁学院,宿迁市223800 [2]西安建筑科技大学,西安市710055 [3]青岛理工大学,青岛市266033

出　　处：《公路》2011年第12期1-5,共5页Highway

基　　金：国家自然科学基金资助项目;项目编号50739001;宿迁学院科研重点基金;项目编号2011KY22

摘　　要：采用压汞试验和中子透射成像技术研究了冻融后表层混凝土孔结构劣化及损伤特性。结果表明:冻融循环作用改变混凝土的微观孔结构的特征,临界孔径成倍数增加,毛细孔等有害孔数量明显增多;表层混凝土在冻融循环作用下孔结构劣化和强度降低更为剧烈,由表及里存在一个损伤梯度。采用表面涂覆或表面浸渍等技术提高表层混凝土抗冻性对延长结构的使用寿命具有重要意义。The micro-porous structure and damage properties of the surface concrete in freeze-thaw environment are studied by means of mercury intrusion test and neutron radiography technique. Results show that the pore structure characteristics of concrete are deteriorated, the critical aperture doubly enlarged and the number of harmful hole significantly increased after freeze-thaw cycles. The pore structure and strength of surface concrete degradation are more serious than the internal concrete, which has a damage gradient from external to internal. So it is very important to improve the frost resistance of surface con- crete for the service life of structure by surface coating or dipping.

关 键 词：表层混凝土 冻融循环 孔结构 劣化 

分 类 号：TU528.01[建筑科学—建筑技术科学]