Behaviour of geopolymer concrete-filled pultruded GFRP short columns

This research paper presents the results of an experimental investigation on the axial compressive behaviour of 24 geopolymer concrete-filled glass fibre-reinforced polymer tubes. The test variables considered are the compressive strength of geopolymer concrete (30 MPa and 35 MPa) and the shape of the cross section (square, circular and rectangular). All the glass fibre-reinforced polymer tubes had the same amount of fibres and similar fibre orientation together with the same aspect ratio. The failure of the square and rectangular columns initiated with the splitting of the corners and resulted in a lower load-carrying capacity compared to the circular columns whose failure was initiated by the crushing of glass fibre-reinforced polymer tube followed by the separation of glass fibre-reinforced polymer tube into strips. It can be concluded that axial load-carrying capacity of square and rectangular sections can be improved by a concrete filler with higher compressive strength. Adopted finite element analysis to simulate the behaviour of the columns is capable of predicting the stress-strain behaviour and the mode of failure.