Behavior of concrete-filled GFRP tube columns under cyclic axial compression

摘要

To study the axial compression performance of glass fiber reinforced polymer (GFRP) tube confined con-crete columns, 13 circular cross-section specimens with 5 mm wall thickness and 500 mm height were designed, including six specimens of recycled concrete columns with different GFRP tube diameters, six specimens of high-strength ordinary concrete columns with different GFRP tube diameters, and one GFRP tube were made. Repeated axial compression tests were conducted on all 13 specimens. The failure pro-cess and failure mode, load & ndash;displacement curve, skeleton curve, characteristic load and displacement, load & ndash;strain curve, and load-residual displacement curve of each specimen were analyzed. The results show that the failure trend of recycled concrete columns confined by GFRP tubes is similar to that of high-strength ordinary GFRP tube confined concrete columns; GFRP tubes effectively increased the axial load bearing capacity of components. Finally, GFRP tubes suffered ring failure with the concrete inside being crushed; the axial load bearing capacity of GFRP empty tubes is relatively low with some brittle-ness characteristics while suffering failure. With the increase in the diameter of GFRP tubes, the load bearing capacity and stiffness of components gradually increase and have a certain degree of ductility. Based on the experimental study, a formula was derived for the axial load bearing capacity of GFRP tube concrete columns. The calculation results are consistent with the experimental results, providing a cer-tain guiding significance for theoretical research and engineering application of GFRP tube concrete columns.(c) 2021 Elsevier Ltd. All rights reserved.