冻融循环与氯盐侵蚀作用下混凝土的损伤模型  

Damage Model of Concrete Subject to Freeze-thaw Cycles Coupled with Chloride Attack

作　　者：杜鹏[1] 姚燕[1] 王玲[1] 曹银[1] 

机构地区：[1]中国建筑材料科学研究总院,绿色建筑材料国家重点实验室,北京100024

出　　处：《硅酸盐通报》2014年第4期841-846,852,共7页Bulletin of the Chinese Ceramic Society

基　　金：国家"973"计划资助项目(2009CB623106;2012CB724602)

摘　　要：越来越多的研究学者使用残余应变表征由冻融引起的混凝土损伤。本文通过快冻法测试了冻融单因素以及冻融与3.5wt%NaCl溶液侵蚀双因素耦合(盐冻)作用下混凝土的残余应变,并结合残余应变的增长是连续的且符合阻滞模型这一特点,建立了同时符合冻融和盐冻作用的混凝土损伤模型。结果显示,混凝土的残余应变变化规律符合冻融损伤机理,它可以用来表征混凝土的冻融损伤程度;冻融损伤模型对各混凝土损伤程度变量曲线的拟合相关系数均在0.95以上,说明该模型能够较好地反映冻融或盐冻过程中混凝土的损伤程度;该模型结合更加全面系统的试验研究工作可以预测特定环境下服役混凝土的寿命,为有抗冻要求的服役混凝土耐久性设计研究提供了新思路。Residual strain has been used to characterize the freeze-thaw damage of concrete by more and more research scholars. The residual strain of concrete subject to single factor （cyclic freeze-thaw） and two factors （cyclic freeze-thaw coupled with 3.5wt% NaCl solution attack） were measured by quick freezing method in the paper. According to that the increase of residual strain is continuous and confirms to the block growth model, the damage model of concrete which meets both the single factor and the two factors was established. The results show that the residual strain variation of concrete conforms to the mechanism of freeze-thaw damage, and it can be used to characterize the degree of freeze-thaw damage in concrete. The correlation coefficients of the damage degree variable curve of concrete fitted by he freeze- thaw damage model are all greater than 0.95, so the model can reflect the damage degree of concrete subject to freeze-thaw cycles or freeze-thaw cycles coupled with chloride attack well. The model can predict the service life of service concrete under specific environment combining with more comprehensive systematic research work, and provide a new idea for durability design of service concrete which has the frost resistance requirement.

关 键 词：混凝土 冻融循环 氯盐侵蚀 残余应变 损伤模型 

分 类 号：TU528[建筑科学—建筑技术科学]