FRP约束损伤混凝土环向应变-轴向应变关系

Lateral strain-axial strain relationship of FRP confined damage concrete

摘要:

为分析混凝土损伤对FRP约束混凝土的影响,通过收集已有文献的264个试验数据,建立一个包含混凝土试件截面形状、损伤种类和损伤程度,以及FRP约束刚度的大型数据库. 基于数据库对现有环向应变-轴向应变关系模型进行评估,并在Jiang等模型的基础上,建立FRP约束损伤混凝土柱的环向应变-轴向应变关系模型,采用数据库对新提出模型的准确性进行验证. 计算结果表明:Jiang等模型可以准确描述FRP约束未损伤混凝土圆柱的环向应变-轴向应变关系,但是现有的FRP约束未损伤混凝土柱的环向应变-轴向应变关系模型不适用于FRP约束损伤混凝土柱； 并且随着混凝土损伤程度的增加,现有模型的计算值与试验值的偏差也在增加. 新提出的模型能够准确描述FRP约束损伤混凝土的环向应变-轴向应变关系,模型可推广应用于FRP约束高温损伤混凝土柱. 新模型既可以同时适用于FRP约束预损伤圆形、正方形、长方形截面混凝土柱,也可以计算FRP约束预加载混凝土圆柱与方柱.

Abstract:

To analyze the influence of concrete damage on FRP confined concrete, 264 test data was collected from published literature, and a large database was established, which contains cross-sectional shapes, damage types, and damage levels of specimens, and FRP confined stiffness. Based on the database, the existing lateral strain-axial strain relationship models were evaluated, and a new lateral strain-axial strain relationship model of FRP confined pre-damage concrete columns was established by modifying Jiang’s model. Results show that Jiang’s model could accurately describe the lateral strain-axial strain behavior of FRP confined undamaged circular concrete columns, but the existing models were not suitable for FRP confined damage concrete columns. With the increase of concrete damage level, the deviation between the calculated value and the test value of the existing models increased. The proposed model was verified by database and could predict the lateral strain-axial strain behavior of FRP confined damage concrete column with good accuracy, which can be applied to FRP confined high temperature damage concrete columns. The model in this paper can be used for FRP confined pre-damage circular, square, and rectangular concrete columns as well as for the calculation of FRP confined preloading concrete columns and square columns.