Abstract: Eleven columns consisting of six plain concrete and five GFRP pipe concrete columns are tested in the paper under axial compression load in the salt solution of different wet-dry cycles environment. The experiment is focused on the analyses of ultimate strengths and strains of the specimens. It is to analyze the effects on the plain concrete columns and the GFRP pipe concrete columns under the salt solution environment and different wet-dry circles, respectively. The experimental results show that, whether at room temperature or in the salt solution corrosive environments, the strength, stiffness and ductility of GFRP pipe concrete columns have different degrees of increase relative to those of in plain concrete columns. With the increase of wet-dry cycles in the salt solution, the clamping band effect of GFRP pipe to the core concrete, which helps increasing the strength, stiffness and ductility of the GFRP pipe concrete columns, have a certain degree of reduction as compared to those at room temperature.

Key words: glass fiber reinforced plastic pipe (GFRP), concrete cylinder column, wet and dry cycles in salt solution, durability