Experimental Study On The Size Effect Of Axial Compression Performance Of Concrete Columns Confined With GFRP

Fiber reinforced composites (FRP) due to good mechanical properties, has been widely used in reinforcement engineering structure.In the existing research, forconstraint of FRP concrete specimens have been put forward relevant analysis model and design formula,but the proposed model did not consider the influence of size effect. Based on this situation, the concrete strength is C40 and the ratio of height to diameter is 3 GFRP confined concrete specimens were studied in differentt wall thickness of GFRP tubespecimens under axial compressive mechanical properties and size effect.Through the comparison of various constitutive model curve andexperimental curve, to find out reasonable analysis model. Based on this model, study the specimen size effect, and correction.Contents and results are as follows:(1) The specimen diameter and wall thickness of GFRP tube as the main parameters, the 18 GFRP tube confined concrete columns under axial compression test, analysis of GFRP confined concrete columns under axial compression bearing capacity, deformation capacity and failure characteristics, stress-strain curve, further analysis of the impact of size effect on the relationship between the stress-strain curve of concrete columns GFRP constraints.(2) On the basis of experimental research, research on wall thickness and diameter of GFRP test tube on the the influence of ultimate bearing capacity, proposed calculation method GFRP constraint axial bearing capacity of concrete columns consider the size effect.(3) Study on the existing FRP confined concrete stress-strain model of GFRP confined concrete cylinder for axial compression.By comparing the stress-strain model calculation curve and experimental curve, Teng model was found to agree well with the experimental data, but the Teng model can not consider the size effect of concrete axial compression column with GFRP constraints.(4) Based on the test results, by modifying calculation formulas of the hoop stress constraint and the ultimate strain of the Teng model, considering the size effect of FRP confined concrete axial compression column stress-strain model. The calculateon curves with the experimental results and the existing large amount of test data comparison, found good agreement.