CFRP加固火灾后钢筋混凝土梁抗剪性能的试验研究

发布时间：2018-05-15 15:48

本文选题：钢筋混凝土 + 梁　；参考：《华侨大学》2013年硕士论文

【摘要】：碳纤维增强复合材料(Carbon Fiber Reinforced Polymer，简称CFRP)在火灾后混凝土结构的加固修复中得到一定应用。然而，目前有关火灾后混凝土梁抗剪加固方面的研究工作未见文献报道。为此，本文从试验、数值计算两方面研究了CFRP加固火灾后混凝土梁的抗剪性能及其设计方法。另外，，本文还比较了未受火时不同规范的混凝土梁抗剪加固式中CFRP抗剪贡献的计算方法。本文的主要工作和结论如下： 1.收集了国内外22根侧面粘贴、26根U形粘贴、28根全包裹粘贴CFRP加固混凝土梁的CFRP抗剪贡献值的试验结果。针对不同的粘贴方式，分别进行了美国规范、欧洲规范和中国规范共三种规范的计算值与试验值的对比分析，并对我国规范的不足提出了部分修正和建议。结果表明：欧洲规范的设计计算公式对侧面粘贴情况的预测结果较好；对U形粘贴情况，中国规范的设计计算公式的预测结果较不可靠；对封闭包裹情况，三种加固规范的计算结果均与实验值吻合较好，其中中国规范的精度最高。 2.开展了2根未受火梁、2根火灾后混凝土梁、4根CFRP加固火灾后混凝土梁的四点加载试验，主要研究参数为剪跨比、CFRP加固量和楼板翼缘。试验结果表明：(1)混凝土梁遭受火灾高温后，其极限承载力显著降低。宽200mm、高300mm的梁受火1h后试件的抗剪承载力降低9.5%。(2) CFRP加固能将火灾后混凝土梁的抗剪承载力提升至未受火试件的105.3%~134.3%，且考虑楼板翼缘的影响，采用“U形包裹+压条”方式加固混凝土梁可取得较好的加固效果。(3)CFRP加固火灾后混凝土梁，可显著提高其极限变形能力，且提高程度随CFRP加固量的增加而增强。(4)梁的剪跨比对CFRP布的加固效果影响较大，剪跨比越大，加固效果越好。 3.利用程序RCSSCF计算了等截面修复后梁截面的混凝土抗拉强度平均折减系数，建议了CFRP加固火灾后混凝土梁抗剪承载力的实用计算公式。
[Abstract]:Carbon fiber reinforced composite (Carbon Fiber Reinforced Polymer, abbreviated as CFRP) has been applied to the reinforcement and repair of concrete structures after fire. However, there is no literature on the study of the shear reinforcement of concrete beams after the fire. For this reason, this paper has studied two aspects of the experiment and numerical calculation of the concrete beams after the fire. In addition, the calculation method of CFRP shear contribution in shear reinforcement of concrete beams with different specifications is also compared. The main work and conclusion of this paper are as follows:
1. the experimental results of the CFRP shear contribution values of 22 side paste, 26 U shaped paste and 28 full wrapped CFRP reinforced concrete beams were collected. The comparison and analysis of the calculated values and the experimental values of three specifications in the United States, Europe and China were carried out respectively. Some amendments and suggestions are put forward. The results show that the prediction results of the design calculation formula of the European standard are better for the side paste situation; for the U shape paste, the prediction results of the Chinese standard design calculation formula are not reliable. The results of the three kinds of reinforcement codes are in good agreement with the experimental values, among them, the results of the calculation are in good agreement with the experimental values. The national standard has the highest precision.
2. to carry out 2 unfired beams, 2 post fire concrete beams and 4 CFRP reinforced concrete beams after the four point loading test. The main parameters are the shear span ratio, the CFRP reinforcement and the floor flange. The test results show that (1) the ultimate load bearing capacity of concrete beams is significantly reduced after the fire is subjected to high temperature. The width of 200mm and the high 300mm beam are subjected to the 1H post test. 9.5%. (2) CFRP reinforcement can improve the shear bearing capacity of concrete beams after fire to the 105.3%~134.3% of unfired specimens after the fire, and the reinforcement of concrete beams with "U parcel + bar" can achieve better reinforcement effect. (3) CFRP reinforced concrete beams can be significantly improved by CFRP. The ultimate deformation capacity and the degree of improvement are enhanced with the increase of CFRP reinforcement. (4) the shear span ratio of the beams has a greater effect on the reinforcement effect of the CFRP cloth, and the greater the shear span ratio, the better the reinforcement effect.
3. using the program RCSSCF to calculate the average reduction coefficient of the concrete tensile strength of the cross section of the rear beam, and suggests a practical formula for the CFRP reinforcement of the shear bearing capacity of the concrete beams after the fire.

【学位授予单位】：华侨大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU375.1

【参考文献】