冻融循环过程中砂浆的湿度和变形  

Humidity and deformation of mortar during freezing and thawing cycle

作　　者：侯云芬[1] 彭小东[1] 吴越恺[1] 王玲[2] 王振地[2] 

机构地区：[1]北京建筑大学北京市高校工程结构与新材料工程研究中心,北京100044 [2]中国建筑材料科学研究总院,北京100024

出　　处：《混凝土》2016年第4期119-122,共4页Concrete

基　　金：国家973项目课题(2012CB724602)

摘　　要：本试验研究了砂浆试块在25次冻融循环过程中温度、湿度和体积的变化。结果表明冻融循环过程中,湿度不仅随温度变化表现出明显的规律,还会影响体积的变化。在降温过程,体积随温度降低逐渐增大,呈直线关系;在升温过程的初期,体积随温度升高逐步减小,也为直线关系,在融化阶段为三次方的曲线关系,说明升温时砂浆体积变化原因更为复杂。同一温度下,降温时的体积变形大于升温时的体积变形,即存在残余变形。随着冻融循环次数的增加,残余变化增大,导致裂缝的形成和发展以及孔结构的变化,最终使砂浆出现剥落等破坏现象。The change of temperature and humidity and deformation during freezing - thawing cycles were studied. It shows that humidi- ty of mortar changes with the change of temperature regularly during freezing - thawing cycles, and the change of humidity also affects the change of volume.The deformation increases with decreasing of temperature as linear relation during freezing period,but it decreases with increasing of temperature as linear relation at first period and as cube relation at last period which shows that the reason caused deformation is more complex during thawing period.It is shown that the change of deformation during freezing period is bigger than that during thawing period even at same temperature which means there is residual deformation.With increasing of times of freezing and thawing cycle, residual deformations increase constantly to cause mortar peeling off because of formation and development of cracking and change of pore structures.

关 键 词：温度 湿度 变形 砂浆 耐久性 

分 类 号：TU528.01[建筑科学—建筑技术科学]