Size-effect Rules Of Square Reinforced Concrete Columns Confined With GFRP Jackets

Fiber Reinforcement Polymer, FRP for short, is a kind of emerging composites for strengthening and repairing in recent years, including Glass Fiber Reinforcement Polymer(GFRP), Carbon Fiber Reinforcement Polymer(CFRP), Basalt Fiber Reinforcement Polymer(BFRP),etc. Among them, GFRP has wider applications for its reasonable price and convenience in harvesting. GFRP is light-weight and high-strength. And it also has high corrosion resistance, good stability, higher elastic modulus and tensile strength. GFRP not only can reduce the corrosion of reinforced concrete structure by external environment, but also constrain the transverse deformation of core concrete so as to improve the ultimate bearing capacity of reinforced concrete structure significantly.There is no technical code about square reinforced concrete columns confined with GFRP jackets. However, square reinforced concrete columns are more common in actual engineering. Accordingly, the study on the mechanical property and size-effect is significant.In order to investigate the influence of winding layers on the mechanical behavior and the size-effect of square reinforced concrete columns confined with GFRP jackets, 9 specimens in three groups are tested in axial compression. At the same time, the finite element model is established by using ANSYS and verified through test. Then extend the operating conditions and investigate the mechanical behavior and the size-effect rules of square reinforced concrete columns confined with GFRP jackets by the both test and numerical simulation.The main research contents include as follows:1. In order to investigate the mechanical properties of square reinforced concrete columns confined with GFRP jackets, three groups of confined specimens and one group of unconfined specimens are designed and manufactured, then tested in axial compression. During the tests, we observe the external change and failure modes, collect the strain and displacement of different materials by static resistance strain set and the displacement meter.2. Establish the finite element model of square reinforced concrete columns confined with GFRP jackets using ANSYS, and verified by the test result.3. Using ANSYS model established above, simulated analysis of square reinforced concrete columns confined with GFRP jackets on experimental design is done. Then investigate the influence of GFRP jackets thickness and the concrete strength grade on the mechanical behavior.4. By comparing the ultimate compressive strength of the specimens with different sizes in the same group, prove the size-effect rules. By comparing the size-effect rules of different groups of specimens, investigate the influence of GFRP jackets thickness and concrete strength grade on the size-effect rules.