Study on Effect of FRP-ECC Reinforcement on Axial Compression Performance of Reinforced Concrete Square Columns
The axial compression performance of FRP-ECC reinforcement for common reinforced concrete square columns is investigated.A finite element model is established by incorporating concrete plastic damage(CDP)and trilinear steel bar characteristic models.Numerical calculations clarify the stress distribution in reinforced concrete after strengthening and examine the influence of FRP thickness and spacing,ECC thickness,and reinforcement ratio on the post-strengthening bearing capacity.Results indicate that the square column ultimately fails as the core concrete cluster enters a plastic state,while the FRP reinforcement strip remains elastic.The reinforcement effect becomes more pronounced with increased FRP sheet and ECC bonding layer thickness and reduced reinforcement strip spacing.When the FRP thickness reaches 20 mm or the ratio of reinforcement strip width to spacing reaches 0.4,the ultimate bearing capacity increases by 11.29%and 5.12%,respectively.Furthermore,for square columns with higher reinforcement ratios,the FRP-ECC reinforcement effect is more significant.