摘要
对采用碳纤维增强复合材料(CFRP)加固的不同损伤程度的钢筋混凝土梁进行落锤冲击试验,以冲击高度、加固层数为试验参数分析CFRP加固损伤试件的裂缝发展、破坏形态及抗冲击性能,并研究试件在冲击荷载下的动力性能。结果表明:试件损伤程度越高,其斜向裂缝发展越密集,试件的破坏程度越严重;落锤冲击高度越高,裂缝发展越趋近于跨中局部化;当采用多层CFRP布加固损伤试件时,试件在落锤冲击作用下保持较好的完整性,仅外部混凝土粉碎掉落;随着CFRP布粘贴层数的增加,试件整体产生弯剪破坏,损伤试件加固修复后的抗冲击能力及刚度相较于完好试件得到显著提升,提升幅度为70%~72%,但增加CFRP布粘贴层数对试件的加固修复效果提升作用有限,且加固效果与抗冲击能力并非呈线性关系;基于有效应变计算的结果可知,采用CFRP布加固修复不仅仅具有加固补强的作用,同时能够在一定的程度上改善试件的整体抗冲击性能。
The drop hammer impact tests were carried out on reinforced concrete beams with different damage degrees strengthened with carbon fiber reinforced polymer(CFRP).Taking the impact height and the number of reinforcement layers as the test parameters,the crack development,failure mode and impact resistance of the damaged specimens strengthened with CFRP were analyzed and the dynamic performance of the specimens under impact load was studied.The results show that the higher the damage degree of the specimen,the denser the oblique crack development and the more serious the damage degree of the specimen.The higher the drop hammer impact height is,the closer the crack development is to the mid-span localization.When the damaged specimens are strengthened with multi-layer CFRP sheets,the specimens maintain good integrity under the impact of drop hammer,and only the external concrete is crushed and dropped.With the increase of the number of CFRP layers,the whole specimen produces bending and shear failure.Compared with the unreinforced specimen,the impact resistance and stiffness of the damaged beams are significantly improved with the increase of the number of CFRP layers,and the improvement amplitude is 70%-72%.However,increasing the number of CFRP layers has limited effect to improve the reinforcement and repair effect of the specimen,and the reinforcement effect is not linearly related to the impact resistance.Based on the results of effective strain calculation,it can be seen that the use of CFRP reinforcement not only has the role of reinforcement,but also can improve the overall impact resistance of the specimen to a certain extent.
作者
余文成
刘浪
刘均利
李治
雷芸
林童
YU Wencheng;LIU Lang;LIU Junli;LI Zhi;LEI Yun;LIN Tong(College of Civil and Architecture Engineering,Guilin University of Technology,Guilin 541004,Guangxi,China;College of Civil Engineering,Minnan University of Science and Technology,Quanzhou 362700,Fujian,China)
出处
《建筑科学与工程学报》
CAS
北大核心
2024年第2期66-74,共9页
Journal of Architecture and Civil Engineering
基金
国家自然科学基金项目(51778153,51468013)
广西科学与技术开发计划项目(桂科攻14251012)。
关键词
CFRP
钢筋混凝土梁
加固修复
落锤冲击
动态响应
抗冲击性能
CFRP
reinforced concrete beam
reinforcement and repair
drop hammer impact
dynamic response
impact resistance
