Flexural Behavior of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer under Hydrothermal Environment
-
摘要: 为研究湿热环境下碳纤维增强复合材料（CFRP）加固钢筋混凝土结构的耐久性问题，采用6根湿热环境下CFRP加固的钢筋混凝土梁进行抗弯性能试验，研究在湿热环境下CFRP加固钢筋混凝土梁的破坏形态、承载力、挠度和裂缝等；根据环氧树脂老化的化学反应微分方程和反应速度的指数定律，给出环氧树脂胶层弹性模量的衰减模型；从混凝土和环氧树脂胶层的力学性能出发，提出湿热环境下CFRP加固钢筋混凝土结构后CFRP剥离时的强度计算公式，推导湿热环境作用下CFRP加固钢筋混凝土梁的抗弯承载力计算公式. 研究结果表明：随着湿热环境作用时间的增加，加固梁的抗弯承载力逐渐减小，CFRP剥离破坏由混凝土控制逐渐转换为由环氧树脂胶层控制；随着湿热环境作用的持续，混凝土裂缝数量减小、裂缝宽度增加但挠度减小，加固梁的损伤增大且脆性增加；加固梁的屈服曲率、极限曲率和曲率延性系数均减小，加固梁的延性变差且CFRP剥离破坏时的脆性和离散性增强；试验与理论计算的对比表明，在湿热环境作用下加固梁发生CFRP剥离破坏时，CFRP极限应变的理论值与试验值误差在20%以内，抗弯承载力的理论值与试验值误差在11%以内.Abstract: To study the durability of concrete structure strengthened with CFRP(carbon fiber reinforced polymer) under hydrothermal environment, six concrete beams strengthened with CFRP under warm and moisture conditions were used for flexural behavior experiment; the failure mode, bearing capacity, deflection and crack were studied by the experiment. Based on differential equations of chemical reactions and exponential law of reaction rate for epoxy resin aging, the attenuation model of elastic modulus was given for epoxy resin under warm and moisture conditions. From the mechanical properties of concrete and epoxy resin, theoretical formula of CFRP peel strength was given for concrete beams strengthened with CFRP under hydrothermal environment, and the flexural capacity formula was also put forward. The results show that the flexural capacity of strengthened concrete beams decrease exposed to environmental conditions, and peeling failure of CFRP is gradually transferring from the interface region of concrete side to the interface region of CFRP side. As the environmental effect continues, the number of cracks and deflection reduce while the crack width increases, which show that both damage and brittleness of strengthened beam increases. The yield curvature, ultimate curvature and curvature ductility factor of the strengthened beam reduce, and it indicates that the ductility of the strengthened beam deteriorates, but the brittleness and dispersion of the CFRP peeling failure increase. The comparison between the experimental and theoretical analysis shows that the relative error of the theoretical and the experimental value is smaller than 20% for CFRP ultimate strain, and the relative error is smaller than 11% for flexural capacity.
-
Key words:
- carbon fiber reinforced polymer sheet /
- peeling /
- hydrothermal environment /
- epoxy resin /
- reaction rate
-
图 3 湿热环境下混凝土抗压强度、环氧树脂胶层弹性模量与时间的关系
Figure 3. Relation ships between concrete compressive strength，epoxy resin’s elastic modulus and exposure duration
图 4 湿热环境下CFRP剥离强度与时间的关系
Figure 4. Relation ships between CFRP’s peel strength and exposure duration
图 5 湿热环境下加固梁的抗弯承载力与时间的关系
Figure 5. Relation ships between flexural capacity and exposure duration
表 1 钢筋的实测力学性能
Table 1. Mechanical property of steel
类别 型号 屈服强度/MPa 极限强度/MPa 延伸率% 弹性模量/GPa 塑性模量/GPa 受拉纵筋 Ф10 333.3 506.5 34.6 204 7.18 架立钢筋和箍筋 Ф8 310.0 500.0 23.0 194 — 
下载: 导出CSV
表 2 CFRP的力学性能
Table 2. Mechanical property of CFRP
规格 理论厚度/mm 抗拉强度/MPa 弹性模量/GPa 伸长率/% WF300 0.167 3 609 243.0 1.71
下载: 导出CSV
表 3 环氧树脂粘结剂的力学性能
Table 3. Mechanical property of epoxy resin
MPa 规格 弹性模量 拉伸强度 压缩强度 剪切强度 弯曲强度 JGN-II ≥ 2 500 ≥ 40 ≥ 70 ≥ 14 ≥ 50
下载: 导出CSV
表 4 试验梁参数
Table 4. Parameters of experimental beams
试验梁编号 混凝土 配筋 粘贴层数/层 试验环境 环境作用时间/d L1 C30 2Φ10 1 正常 0 L2 C30 2Ф10 1 湿热 5 L3 C30 2Ф10 1 湿热 10 L4 C30 2Ф10 1 湿热 15 L5 C30 2Ф10 1 湿热 30 L6 C30 2Ф10 1 湿热 60
下载: 导出CSV
表 5 承载力试验结果
Table 5. Experimental results
试验梁
编号试验
环境环境用
时间/d开裂荷载/kN 与 L1 的
比值/%屈服荷载/kN 与 L1 的
比值/%极限荷载/kN 与 L1 的
比值/%CFRP极限
应变/× 10−6与 L1 的
比值/%破坏形态 L1 正常 0 8.80 100 26.73 100 40.01 100 6 926 100 中部裂缝
处剥离L2 湿热 5 8.90 101 24.96 94 40.42 101 6 527 94 L3 湿热 10 10.59 120 24.10 90 39.62 99 6 061 88 L4 湿热 15 10.82 123 22.99 86 39.29 98 6 018 87 L5 湿热 30 9.54 108 23.10 87 38.51 96 5 733 83 L6 湿热 60 7.30 83 22.71 85 37.20 93 5 150 74
下载: 导出CSV
表 6 裂缝与挠度试验结果
Table 6. Experimental results of crack and deflection
试验梁
编号试验
环境环境作用
时间/d裂缝
数量与 L1 的
比值/%平均裂缝
间距/mm与 L1 的
比值/%最大裂缝
宽度/mm与 L1 的
比值/%极限挠度/mm 与 L1 的
比值/%L1 正常 0 11 100 96.8 100 0.86 100 12.36 100 L2 湿热 5 11 100 86.4 89 0.91 106 11.91 96 L3 湿热 10 10 91 89.6 93 0.95 110 11.83 96 L4 湿热 15 10 91 98.4 102 1.04 121 10.05 81 L5 湿热 30 9 82 106.2 110 1.12 130 9.91 80 L6 湿热 60 9 82 101.5 105 1.17 136 8.46 68
下载: 导出CSV
表 7 曲率延性
Table 7. Experimental results of curvature ductility
试验梁
编号试验
环境环境作用
时间/d屈服曲率
/（× 10−6•mm−1）与 L1 的
比值/%极限曲率
/（× 10−6•mm−1）与 L1 的
比值/%曲率延性
系数与 L1 的
比值/%L1 正常 0 14.88 100 58.25 100 3.91 100 L2 湿热 5 14.84 99.7 53.02 91.0 3.57 91.3 L3 湿热 10 14.89 100 50.58 86.8 3.40 87.0 L4 湿热 15 14.72 98.9 53.48 91.8 3.63 92.8 L5 湿热 30 14.71 98.9 52.79 90.6 3.59 91.8 L6 湿热 60 14.67 98.6 49.62 85.2 3.38 86.4
下载: 导出CSV
表 8 弹性模量衰减与时间的关系
Table 8. Relationship between βaa and d
d/d 0 5 10 15 30 60 βaa 1.00 0.90 0.85 0.80 0.75 0.66
下载: 导出CSV
表 9 理论值与试验值的比较
Table 9. Comparison between theoretical and experimental values
试验梁编号 试验环境 环境作用时间/d CFRP 极限应变/× 10−6 极限荷载/kN 试验值 理论值 比值/% 试验值 理论值 比值/% L1 正常 0 6 926 6 362 92 40.01 35.81 90 L2 湿热 5 6 527 6 322 97 40.42 35.73 89 L3 湿热 10 6 061 6 319 104 39.62 35.72 90 L4 湿热 15 6 018 6 311 105 39.29 35.71 91 L5 湿热 30 5 733 6 280 110 38.51 36.65 95 L6 湿热 60 5 150 6 200 120 37.20 35.50 95
下载: 导出CSV
-
刘超越. 荷载/湿热环境作用下粘贴CFRP加固钢筋砼梁的耐久性研究[D]. 重庆: 重庆交通大学, 2016 任慧韬,胡安妮,姚谦峰. 湿热环境对FRP加固混凝土结构耐久性能的影响[J]. 哈尔滨工业大学学报,2006,38(11): 1996-1999. doi: 10.3321/j.issn:0367-6234.2006.11.045REN Huitao, HU Anni, YAO Qianfeng. The influence of wet-thermal condition on durability behavior of concrete structures strengthened by FRP[J]. Journal of Harbin Institute of Technology, 2006, 38(11): 1996-1999. doi: 10.3321/j.issn:0367-6234.2006.11.045 任慧韬,胡安妮,姚谦峰. 纤维增强聚合物加固混凝土结构耐久性能研究[J]. 大连理工大学学报,2005,45(6): 847-852. doi: 10.3321/j.issn:1000-8608.2005.06.015REN Huitao, HU Anni, YAO Qianfeng. Research on durability of concrete structures strengthened with FRP laminates[J]. Journal of Dalian University of Technology, 2005, 45(6): 847-852. doi: 10.3321/j.issn:1000-8608.2005.06.015 AU C, BUYUKOZTURK O. Peel and shear fracture characterization of debonding in FRP plated concrete affected by moisture[J]. Journal of Composites for Construction, 2006, 10(1): 35-47. doi: 10.1061/(ASCE)1090-0268(2006)10:1(35) OUYANG Zhengyu, WAN Baolin. Nonlinear deterioration model for bond interfacial fracture energy of FRP-concrete joints in moist environments[J]. Journal of Composites for Construction, 2009, 13(1): 53-63. doi: 10.1061/(ASCE)1090-0268(2009)13:1(53) DAI J G, YOKOTA H, IWANAMI M, et al. Experimental investigation of the influence of moisture on the bond behavior of FRP to concrete interfaces[J]. Journal of Composites for Construction, 2010, 14(6): 834-844. doi: 10.1061/(ASCE)CC.1943-5614.0000142 ZHANG Pu, WU Gang, ZHU Hong, et al. Mechanical performance of the wet-bond interface between FRP plates and cast-in-place concrete[J]. Journal of Composites for Construction, 2014, 18(6): 04014016-1-04014016-9. doi: 10.1061/(ASCE)CC.1943-5614.0000472 STRATFORD T J, BISBY L A. Effect of warm temperatures on externally bonded FRP strengthening[J]. Journal of Composites for Construction, 2012, 16(3): 235-244. doi: 10.1061/(ASCE)CC.1943-5614.0000260 JAIPURIAR A, FLOOD J P, BAKIS C E, et al. Glassy-rubbery transition behavior of epoxy resins used in FRP structural strengthening systems[C]//The 5th International Conference on FRP Composites in Civil Engineering. Berlin: Springer, 2011: 10-25. 郑小红. 湿热环境下CFL-混凝土界面粘结-滑移机理研究[D]. 广州: 华南理工大学, 2014 宋亮辉. 湿热环境下FRP-混凝土界面粘结性能的耐久性试验研究[D]. 广州: 广东工业大学, 2016 BETONBAN. Fib model code for concrete structures: 2010 CEB-FIP[S]. Berlin: Wilhelm Ernst & Sohn, 2013 BILOTTA A, FAELLA C, MARTINELLI E, et al. Indirect identification method of bilinear interface laws for FRP bonded on a concrete substrate[J]. Journal of Composites for Construction, 2012, 16(2): 171-184. doi: 10.1061/(ASCE)CC.1943-5614.0000253 SHRESTHA J, UEDA T, ZHANG D. Durability of FRP concrete bonds and its constituent properties under the influence of moisture conditions[J]. Journal of Materials in Civil Engineering, 2015, 27(2): A4014009-1-A4014009-14. DAI J G, GAO W Y, TENG J G. Bond-slip model for FRP laminates externally bonded to concrete at elevated temperature[J]. Journal of Composites for Construction, 2013, 17(2): 217-228. doi: 10.1061/(ASCE)CC.1943-5614.0000337 OBAIDAT Y T, HEYDEN S, DAHLBLOM O. Evaluation of parameters of bond action between FRP and concrete[J]. Journal of Composites for Construction, 2013, 17(5): 626-635. doi: 10.1061/(ASCE)CC.1943-5614.0000378 中华人民共和国住房和城乡建设部. 混凝土结构设计规范: GB 50010—2010[S]. 北京: 中国建筑工业出版社, 2011 宋文娟. 玻纤增强环氧树脂复合材料耐海水腐蚀行为与寿命预测[D]. 哈尔滨: 哈尔滨工业大学, 2014 苗蓉丽, 闫素云,殷胜昔,等. 两种环氧树脂灌封料使用寿命研究[J]. 航空兵器,2006(2): 53-55. doi: 10.3969/j.issn.1673-5048.2006.02.015MIAO Rongli, YAN Suyun, YIN Shengxi, et al. Study on the life of two kinds of epoxy resin[J]. Aero Weaponry, 2006(2): 53-55. doi: 10.3969/j.issn.1673-5048.2006.02.015 吕小军,张琦,马兆庆,等. 湿热老化对碳纤维/环氧树脂基复合材料力学性能影响研究[J]. 材料工程,2005(11): 50-53. doi: 10.3969/j.issn.1001-4381.2005.11.014LÜ Xiaojun, ZHANG Qi, MA Zhaoqing, et al. Study of hydro thermal aging effect on mechanical properties of carbon fiber/epoxy resin composites[J]. Journal of Materials Engineering, 2005(11): 50-53. doi: 10.3969/j.issn.1001-4381.2005.11.014 AYDIN H, GRAYINA R J, VISINTIN P. Durability of adhesively bonded FRP-to-concrete joints[J]. Journal of Composites for Construction, 2016, 20(5): 04016016-1-04016016-19. TOUTANJI H, HAN M, GHORBEL E. Interfacial bond strength characteristics of FRP and RC substrate[J]. Journal of Composites for Construction, 2015, 16(1): 35-46. TOUTANJI H, SAXENA P, ZHAO L, et al. Prediction of interfacial bond failure of FRP:concrete surface[J]. Journal of Composites for Construction, 2007, 11(4): 427-436. doi: 10.1061/(ASCE)1090-0268(2007)11:4(427) 四川省住房和城乡建设厅. 混凝土结构加固设计规范: GB 50367—2013[S]. 北京: 中国建筑工业出版社, 2014 期刊类型引用(17)
1. 王卫东，高文生，龚维明，林毅峰，刘永超，吴江斌. 基础工程技术的发展与创新. 土木工程学报. 2025(02): 97-117 . 
百度学术2. 贺蔚，周红星，秦杭晓，曾庆林，张健，徐辉. 高雷诺数下倒虹吸闸墩绕流水力特性. 水电能源科学. 2024(04): 155-159 . 百度学术3. 吴少玲，孔词. 北坑水库泄洪对下游高速公路大桥桥墩的影响分析. 安徽水利水电职业技术学院学报. 2024(06): 12-17+23 . 百度学术4. 胡邵凯，杨万里，边莉，王浩，孔德祥，赵晋平. 基于混凝土塑性损伤模型的桥墩在快速水流作用下的损伤分析. 交通运输研究. 2023(01): 143-152 . 百度学术5. 郑建，贾宏宇，吴炜昌，程维，邹作家，郑史雄. 急流冲击下大跨度连续刚构桥动力响应分析. 铁道标准设计. 2023(03): 121-125 . 百度学术6. 吴春利，黄诗茗，李魁，顾正伟，黄晓明，张炳涛，杨润超. 基于数值仿真和统计分析的洪水作用下桥墩作用效应分析. 吉林大学学报(工学版). 2023(06): 1612-1620 . 百度学术7. 杨光，冀楠，舒麟棹，钱志鹏，万德成. 防撞浮箱对桥墩绕流影响的数值研究. 水动力学研究与进展A辑. 2023(04): 528-534 . 百度学术8. 卞晨杰，杜礼明，王尕平，于德壮. 风-浪-流耦合作用下跨海斜拉桥涡动力特性. 中国科技论文. 2023(10): 1128-1136 . 百度学术9. 杨万理，秦军武，侯海林，吴文博，周凌远. 竹巴龙金沙江大桥水毁破坏机理. 西南交通大学学报. 2022(01): 120-128 . 
本站查看10. 刘洋，徐毅，王茂枚，赵钢，王远. 方形桥墩紊动特性及尾涡区尺寸PIV试验. 水利水电科技进展. 2022(04): 55-60 . 百度学术11. 华旭刚，邓武鹏，陈政清，唐煜. 水流作用下双圆柱墩混凝土梁桥的动力响应实测与数值模拟. 工程力学. 2021(01): 40-51 . 百度学术12. 陈星宇，徐昕宇，郑晓龙，曾永平，李永乐. 中央开槽宽度对箱梁涡振特性的影响机理. 西南交通大学学报. 2021(02): 238-245 . 本站查看13. 郭辉，王明慧，李开兰，蒋树平，周勤. 复杂河道环境内水流冲击桥墩的数值模拟——以广安五福桥为例. 科学技术与工程. 2021(30): 13086-13094 . 百度学术14. 魏凯，秦顺全，赵文玉，祝兵，徐国际. 桥梁水动力学2020年度研究进展. 土木与环境工程学报(中英文). 2021(S1): 31-42 . 百度学术15. 陈一路，王贵. 基于通信特征分析的智能桥梁防撞偏航预警系统. 西安工程大学学报. 2021(06): 83-89 . 百度学术16. 吴承伟，杨万理，王广俊. 错置双柱式桥墩三维流场及水流力特征研究. 水动力学研究与进展(A辑). 2020(03): 328-337 . 百度学术17. 武守信，何亚东，江昕宇. 桥梁基础工程2019年度研究进展. 土木与环境工程学报(中英文). 2020(05): 159-167 . 百度学术其他类型引用(22)
-
下载:
百度学术
点击查看大图
图(5) / 表(9)
计量
- 文章访问数: 621
- HTML全文浏览量: 296
- PDF下载量: 12
- 被引次数: 39