碳纤维布加固损伤再生混凝土梁受弯性能研究  

Study on flexural capacity of damaged recycled aggregate concrete beams strengthened with CFRP sheets

作　　者：延永东[1] 武珂珂 陆春华[1] 梁晓封 季光前 YAN Yongdong;WU Keke;LU Chunhua;LIANG Xiaofeng;JI Guangqian(Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang 212003,Jiangsu,China)

机构地区：[1]江苏大学土木工程与力学学院,江苏镇江212003

出　　处：《建筑科学与工程学报》2024年第5期113-122,共10页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(51608233,51878319,52108147)。

摘　　要：为研究因承受荷载而产生损伤的再生混凝土梁经碳纤维布加固后的受弯性能,选取不同的再生骨料取代率,设计了9根再生混凝土梁;通过预加弯曲荷载使试验梁产生初始损伤,卸载后在损伤梁底部粘贴不同宽度的碳纤维布进行加固,再对试验梁进行受弯承载力试验;考虑再生骨料掺量及预损伤程度的影响,提出了碳纤维布加固损伤再生混凝土梁发生剥离破坏时的受弯承载力计算公式。结果表明:因预损伤产生的裂缝降低了碳纤维布与再生混凝土梁间的黏结强度,加固梁均发生了剥离破坏;随再生骨料取代率的增加,试验梁在相同荷载下产生的裂缝宽度和数量逐渐增加,极限承载力有所减小;随碳纤维布加固宽度的增大,试验梁破坏时的挠度减小,极限承载力提高,裂缝分布细而密;随预损伤程度的增大,试验梁破坏时的裂缝宽度逐渐增大,数量明显增多,但极限承载力和挠度变化并不明显;受弯承载力计算值与试验值吻合较好,研究成果可为碳纤维布加固损伤再生混凝土梁的受力性能评估提供参考。In order to investigate the flexural performance of recycled aggregate concrete(RAC)beams which were damaged by load and then reinforced with carbon fiber reinforced polymer(CFRP)sheets,9 RAC beams were designed by selecting different replacement rates of recycled aggregate.The initial damage of test beam was obtained by preloading.After unloading,CFRP sheets of different widths were pasted at the bottom of the damaged beam for reinforcement,and then bending bearing capacity tests were conducted on the test beam.Considering the influence of recycled aggregate content and pre-damage degree,a formula for calculating the flexural capacity of the damaged recycled concrete beam strengthened by CFRP sheet during delamination failure was proposed.The results show that the cracks caused by pre-damage reduces the bonding strength between CFRP sheets and RAC beams,and the reinforced beams all exhibit debonding failure.As the replacement rate of recycled aggregate increases,the width and number of cracks generated by the test beam under the same load gradually increase,and the ultimate bearing capacity decreases.As the width of CFRP sheet increases,the deflection during the failure of test beam decreases,the ultimate bearing capacity increases,and the crack distribution is fine and dense.As the degree of pre-damage increases,the crack width and number during the failure of test beam gradually increase,but the changes in ultimate bearing capacity and deflection are not significant.The calculated bending bearing capacity values are in good agreement with the experimental values.The research results can provide reference for the evaluation of the mechanical performance of damaged RAC beams strengthened with CFRP sheets.

关 键 词：再生混凝土梁 碳纤维布 再生骨料取代率 受弯性能 

分 类 号：TU375.1[建筑科学—结构工程]