加固层厚度对PVA⁃RFCC加固梁弯曲性能的影响  

Effect of Composite Reinforcement Layer Thickness on Flexural Behavior of Reinforced Concrete Beams Strengthened with PVA⁃RFCC

作　　者：杜文平 杨才千[1,2] 王冲 DU Wenping;YANG Caiqian;WANG Chong(Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education,Southeast University,Nanjing 210096,China;College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096 [2]湘潭大学土木工程与力学学院,湘潭411105

出　　处：《材料导报》2021年第4期4067-4073,共7页Materials Reports

基　　金：湖南省重点研发计划(2018WK2111);湖南省创新技术投资项目(2018GK5028)。

摘　　要：为了提高加固构件的抗裂性能和极限承载力,提出一种聚乙烯醇纤维增强钢丝网水泥基复合(PVA⁃RFCC)新型加固材料,是由钢筋网和钢丝网作为增强材料,聚乙烯醇纤维水泥基复合材料(PVA⁃ECC)作为基体构成。设计7根加固梁和1根对比梁进行四点弯试验,重点探讨了加固层(CRL)厚度对加固梁抗弯性能的影响。同时,对最佳CRL厚度计算表达式进行推导。结果得出:当CRL仅为PVA⁃ECC或仅含钢丝网(SM)时,试验梁弯曲性能随着CRL厚度增大而降低;当CRL中包含钢筋网(RM)或SM⁃RM时,试验梁弯曲性能随着CRL厚度的增大而增强。CRL厚度与极限荷载呈二次函数关系,SM⁃RM是最优加固方式,SM主要提高试验梁延性,RM主要提高试验梁的承载力和刚度。结合试验和理论计算结果,得出CRL为PVA⁃ECC或仅含SM时,试验梁的最佳CRL厚度为40 mm;仅加RM或SM⁃RM时,最佳CRL厚度为60 mm。In order to both improve the crack resistance and ultimate load carrying capacity of reinforcement member significantly. A new type of polyvinyl alcohol fiber reinforced ferrocement engineered cementitious composite(PVA-RFCC) was proposed, which was composed of reinforcement mesh(RM) and steel mesh(SM) as a reinforcing element and polyvinyl alcohol fiber engineered cementitious composite(PVA-ECC) as a matrix. Seven strengthened beams and one control beam(CB) were prepared and tested using four-point bending system. Composite reinforcement layer(CRL) thickness was main parameter for investigating the influence of flexural behavior. Simultaneously, the expression of optimum CRL thickness was deduced. The results showed that the flexural behavior of the strengthened beams decreased with increasing CRL thickness when PVA-ECC was included or SM was added to the CRL, whereas they increased when RM was included or SM-RM was added to the CRL. The relationship between the CRL thickness and ultimate load was quadratic function. The coupling effect of SM-RM provided the best strengthening method, the SM can improve the ductility, and the RM can improve the load carrying capacity and stiffness. Combined with the experimental and theoretical results, the optimum CRL thickness was 40 mm when the PVA-ECC was included or SM was added to the CRL, and was 60 mm when RM or SM-RM was added in strengthened beams.

关 键 词：钢筋网 钢丝网 加固层厚度 弯曲性能 延性 刚度 

分 类 号：TU375.1[建筑科学—结构工程]