Compressive behaviour of concrete-filled multi-cell GFRP pultruded square columns reinforced with lattice-webs

Experimental studies have generally confirmed the good mechanical performance of the pultruded tubes, while brittle buckling failure and low confining efficiency are still the problems to be addressed. Against this background, a concrete-filled multi-cell glass fibre-reinforced polymer (GFRP) pultruded column reinforced with lattice-webs (ML-CFPT) was proposed, and an experimental study on the compressive behaviour of square ML-CFPTs was presented in this paper. A total of 18 specimens including 6 control specimens and 12 multi-cell columns with/without lattice-webs were tested, with the studied parameters covering the thicknesses of face sheets and lattice-webs. The test results revealed that multi-cell structures improved the brittle failure manner of the pultruded tubes, and applications of lattice-webs delayed the local buckling of pultruded tubes thus exhibiting better confinement effectiveness. Furthermore, a simple design-oriented model on the basis of test results was proposed to predict the bilinear ascending stress–strain curve of the confined concrete in ML-CFPTcs, and the results were consistent with the test data.