极温冻融-荷载作用下碳纤维复合材料修复试件损伤分析  

Analysis of damage model of mortars strengthened with CFRP under ultimate freeze-thaw and load

作　　者：谷拴成[1] 聂红宾 GU Shuan-cheng;NIE Hong-bin(School of Architecture and Civil Engineering,Xi′an University of Science and Technology,Xi′an 710054,China;College of Rail Engineering,Shaanxi Railway Institute,Wei Nan 714000,China)

机构地区：[1]西安科技大学建筑与土木工程学院,西安710054 [2]陕西铁路工程职业技术学院轨道工程学院,陕西渭南714000

出　　处：《吉林大学学报（工学版）》2021年第6期2108-2120,共13页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(51868075);陕西省教育厅专项基金项目(21JK0584);渭南市科技项目(2020ZDYF-JCYJ-187,2019-ZDYF-JCYJ-129);陕西铁路工程职业技术学院中青年科技创新人才项目(KJRC201810)。

摘　　要：为了研究碳纤维复合材料(CFRP)对冻融损伤混凝土柱的修复效果,按照混凝土耐久性及碳纤维加固规范要求,对混凝土试件进行冻融0、50、100、150、200次后,采用不同修复间距、不同纤维量CFRP,对其进行修复,再进行轴压试验,以压缩荷载、竖向整体位移、膨压比等为参数研究试件微观结构下CFRP修复冻融损伤受压性能,提出了CFRP修复冻融损伤混凝土受压模型。试验结果表明:冻融循环对混凝土抗压性能影响很大,CFRP修复技术能够有效提高冻融损伤混凝土抗压承载力,最大可提高630.6%,同时,CFRP修复试件承载力的提高与修复间距无关,而与CFRP的纤维量有关。修复试件的竖向整体位移随着冻融次数的增加而增大,随着CFRP修复间距的增大而减小。膨压比随着冻融循环先减小后增大再减小,膨压比峰值从"凸"型逐渐变为"凹"的塌陷底峰值,且峰值距离逐渐减小。通过纤维修复混凝土冻融损伤微观分析,建立了混凝土粘塑性损伤模型,研究了混凝土破坏过程及荷载-应变关系,验证了模型合理性。In order to study repair effect of concrete column wrapped Carbon Fiber Reinforced Plastics(CFRP)after extreme freeze-thaw environment,according to the requirements of code of China’s current concrete durability(GB/T 50476—2008)and technical specifications for strengthening concrete structures with carbon fiber reinforced polymer laminate,axial pressure test was designed by concrete members wrapped by different spacing and dosage CFRP after freeze-thaw cycle 0 times,50 times,50 times,100 times,150 times and 200 times. The compression properties of concrete repaired with CFRP were studied by sample microstructure and considering three factors:compression load,vertical overall displacement and the ratio of expansion and compression. The results show the freeze-thaw has a more significant impact on compressive strength,but the compressive strength of freezing-thawing damaged concrete can be improved effectively after CFRP repair,up to 630.6%,and the improvement of the bearing capacity of specimens repaired with CFRP is not related to the repair spacing,but to the fiber amount of CFRP. The overall vertical displacement increases with the increase of freezing-thawing times,and decreases with the increase of the repaired CFRP. With the freezing-thawing cycle,the ratio of expansion and compression first decreases,then increases and then decreases,and the first peak value first increases and then decreases,and the second peak gradually decreases from the "convex" peak gradually to the peak of the collapse of the concave, and the distance between the two peaks gradually decreases. Through microstructure analysis,thechange of the ratio of expansion and compression is mainly caused by freezingthawing increasing compression and hoop effect of CFRP.

关 键 词：土木工程 碳纤维复合材料 冻融循环试验 压力试验 微观分析 损伤模型 

分 类 号：TU531[建筑科学—建筑技术科学]