冻融循环下混凝土热应力影响因素的研究  

Study on the influence factors of thermal stress of concrete under freezing and thawing cycles

作　　者：孙红运 方从启[1] 蔡蔚 郭保林 

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]上海轨道交通十三号线发展有限公司,上海200070 [3]山东高速科技发展集团有限公司,山东济南250003

出　　处：《混凝土》2017年第5期29-32,38,共5页Concrete

基　　金：国家自然科学基金项目(51178264);铁道部科技研究开发计划项目(J2011G003)

摘　　要：以钢筋混凝土构件的冻融循环试验为背景,利用ABAQUS有限元分析软件通过建立热力耦合作用下的数值模型,对受冻融作用下混凝土构件的温度场及热应力场进行研究,并在此基础上进行拓展,分析了水灰比、外部最低冻结温度、降温速率及钢筋对混凝土热应力的影响。研究结果表明:随着温度不断地循环变化,混凝土的内外应力场也不断循环变化,且逐渐增大;冻融120次后,外部的应力是内部的3倍,说明冻融循环对混凝土的表面损伤较大,混凝土的冻融损伤是由外向内发展;钢筋混凝土的热应力较素混凝土的增加了14%,钢筋的存在加剧了混凝土的损伤程度。In the reinforced concrete freeze-thaw cycle test as the background,through the establishment of a thermo mechanical coupling effects of the numerical model using finite element analysis software ABAQUS,freezing and thawing under the action of concrete temperature field and thermal stress field of research,and on this basis to expand,analyzes the water cement ratio,minimum external freezing temperature,cooling rate and reinforcement of concrete thermal stress effects.The results of the study show that with temperature constant circulation change,internal and external concrete should force field also continuous cycle changes,and gradually increased;after the freeze thaw 120 times,external stress is within three times,freezing and thawing cycles on the concrete surface damage larger,concrete freeze-thaw damage is developed from the outside to the inside.Reinforced concrete thermal stress compared with plain concrete increased by 14%,the existence of the steel bar,exacerbated by the extent of damage to the concrete.

关 键 词：混凝土 冻融循环 热力耦合 热应力 影响因素 

分 类 号：TU528.01[建筑科学—建筑技术科学]