Analysis of the efficiency of strengthening design models for reinforced concrete columns

Abstract This paper develops a comparative analysis of the main design models used for predicting the strengthening of reinforced concrete columns subjected to uniaxial compression. The study evaluated four strengthening design models with concrete jackets and eleven strengthening design models with wrapping in Carbon Fiber-Reinforced Polymer (CFRP). All models consider the effect of confinement provided by the transverse steel reinforcement and the CFRP sheet wrapping on the gain in resistance of the column. For the validation, a database was formulated containing 135 experimental results of columns tested by several researches, which was used to analyze all design models and identify which was best for expressing the behavior of the strengthened column. At the end of the study, one confinement design model with transverse reinforcement and eleven design models with confinement provided by CFRP sheet wrapping and transverse steel reinforcement which showed the best resistance predictions were selected.摘要 本文针对单轴受压钢筋混凝土柱加固预测所用的主流设计模型开展对比分析。本研究评估了4种采用混凝土套箍的加固设计模型，以及11种采用碳纤维增强聚合物（Carbon Fiber-Reinforced Polymer, CFRP）缠绕的加固设计模型。所有模型均考虑了横向钢筋与CFRP片材缠绕所提供的约束效应对柱抗承载力提升的影响。为开展模型验证，研究构建了包含135组柱体试验实测数据的数据库，以此对所有设计模型进行分析，并遴选出最能准确表征加固柱受力行为的模型。研究最终筛选出1种仅考虑横向钢筋约束的设计模型，以及11种同时采用CFRP片材缠绕与横向钢筋约束的设计模型，上述模型均展现出最优的抗承载力预测精度。