Investigation on various section GFRP profile strengthening concrete-filled GFRP tubular columns

Axial compression tests and numerically investigates were presented to investigate the behavior of circular winding concrete filled GFRP tubular columns with inner various section shapes of pultruded GFRP including angle section pultruded GFRP (LG-CFGT), channel section pultruded GFRP (CG-CFGT) and I section pultruded GFRP (IG-CFGT). A total of 72 columns including three groups of 24 LG-CFGT columns, 24 CG-CFGT columns and 24 IG-CFGT columns with different concrete strength, different winding GFRP tubular thickness and different column heights were tested. The failure mode, ultimate capacity, ductility, and stiffness of columns were mainly analyzed. Besides, strain development of the three groups' columns during the test was investigated according to the strain measurement of eight columns. Based on mechanical mode and test results of core concrete being confined with GFRP tube, the calculate formula was presented in this study to predict the ultimate capacity of various section GFRP profile strengthening concrete-filled GFRP tubular columns. The calculated results were greatly consistent with the test results. In addition, the finite element model was proposed in this study, and was validated by comparing with the test results.

Automated summary

This study investigates the behavior of circular winding concrete filled GFRP tubular columns with various inner section shapes. Through axial compression tests and numerical analysis, different parameters of columns were tested and analyzed. The failure mode, ultimate capacity, ductility, and stiffness of the columns were analyzed, and a calculation formula was proposed to predict the ultimate capacity of different section GFRP profile strengthening concrete-filled GFRP tubular columns. The formula was validated using a finite element model.