荷载损伤对混凝土微裂缝和氯离子侵蚀的影响研究  

Influence of higher stress on chloride ion corrosion in concrete

作　　者：陆文攀[1] 赵铁军[1] 马志鸣[1,2] 张鹏[1] 

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033 [2]同济大学建筑工程系,上海200092

出　　处：《混凝土》2015年第6期54-57,共4页Concrete

基　　金：国家自然科学基金资助项目(51278260);国家重点基础研究发展计划"973"项目(2015CB655100);国家基金重点国际合作项目(51420105015)

摘　　要：研究荷载损伤对混凝土中微裂缝和氯离子侵蚀的影响,在65%、75%、85%三种轴压应力水平,分别持载10、50、250、1 250 min,测定整个加载过程中的纵横向应变,通过比裂缝面积评价混凝土的扩展微裂缝,卸载后,通过毛细吸收试验,测定混凝土7d的毛细吸水量和28 d的氯离子含量,试验结果表明:混凝土的扩展微裂缝随着应力水平及持载时间的增加而增加,残余微裂缝也随着应力水平及持载时间的增大而增大;同一应力水平下,在持载时间较短时(≤250 min),平行轴力方向的毛细吸收和抗氯离子侵蚀和垂直于轴力方向的相差不大,但当持载时间较长时(1250 min),平行轴力方向的毛细吸收和抗氯离子侵蚀和垂直于轴力方向的有较大差别,平行轴力方向的毛细吸收作用稍小一些,抗氯离子侵蚀性能稍差一些。The load damage has a great influence on micro crack and chloride ion corrosion in concrete.The prisms were under 65%,75%,85%three stress levels,sustained for 10,50,250,1 250 min respectively.During the duration the longitudinal strain and the transverse strain were measured.A method of evaluation of the specific crack area was used to characterize the micro-cracking in concrete.Then unload and cut.The specimens were put in contact with 5%NaCl for 28 d.And the value of water absorption and the chloride ion were measured.Results show that the micro cracks extended with the increase of stress level and the loading time.So did the residual micro fracture.Under the same stress level,when the loading time was shorter（less than 250min）,the capillary absorption and the resistance to chloride ion erosion had little difference in the two directions parallel and normal to the axial compressive load,but when the loading time was longer（1 250 min）,the rule of capillary absorption and resistance to chloride ion erosion in the two directions was different.

关 键 词：应力 微裂缝 比裂缝面积 毛细吸收 氯离子侵蚀 

分 类 号：TU528.01[建筑科学—建筑技术科学]