考虑尺寸效应影响的FRP筋混凝土构件纯扭承载力计算方法

CALCULATION METHOD FOR PURE TORSIONAL CAPACITY OF FRP REINFORCED CONCRETE MEMBERS CONSIDERING SIZE EFFECT

纤维增强聚合物(FRP)筋作为非腐蚀材料替代钢筋已成为解决锈蚀问题的创新方案,被应用于预应力结构、海洋平台、沿海码头和长期处于浸蚀性化学环境的构件中。关于FRP筋混凝土构件的纯扭承载力设计方法只有加拿大规范CSA S806-12提出,且以借鉴现有的钢筋混凝土构件纯扭承载力计算公式的形式给出,考虑了FRP筋与钢筋间材料力学参数的区别。该文通过已验证了的三维细观数值模拟方法,研究了最大横截面宽度为1000 mm的FRP筋混凝土柱纯扭破坏行为,揭示了其名义抗扭强度尺寸效应规律。基于模拟数据,对比了现有的FRP筋混凝土构件纯扭承载力计算公式,并在中国规范GB 50010-2010关于钢筋混凝土构件纯扭承载力计算方法的基础上,提出了考虑尺寸效应影响的FRP筋混凝土构件纯扭承载力的计算方法。通过对比现有的试验数据,验证了所提公式的正确性和合理性。

Fiber reinforced polymer(FRP)bar,as a non-corrosive alternative material to steel bar,it has become a viable solution for corrosion problems of steel.FRP bars have been widely used in prestressed structures,offshore platforms,coastal wharfs and components exposed to long-term corrosion chemical environments.At present,the design method of pure torsional capacity of FRP reinforced concrete members is seldom proposed except for the CSA S806-12.It is primarily presented in a modified form of the existing formula for calculating the pure torsional capacity of reinforced concrete members,considering the difference of material mechanical parameters between FRP bars and steel bars.In this paper,a pure torsional failure behavior of FRP reinforced concrete columns with a maximum cross-section width of 1000 mm was studied and,the size effect law of nominal torsional strength was revealed by using inspected three-dimensional meso-numerical simulation methods.Based on the simulation data,the existing calculation formulas of the pure torsional capacity of FRP reinforced concrete members were compared.In addition,upon the GB 50010-2010 on the calculation method of pure torsional capacity of reinforced concrete components,a calculation method of pure torsional capacity of FRP reinforced concrete members considering size effect was proposed.By comparing the existing test data,the correctness and rationality of the proposed formula were verified.