Testing and modelling of geopolymer concrete members with fibreglass reinforcement

The poor durability of ordinary Portland cement concrete and the corrosion of conventional steel reinforcement have a major impact on the viability, safety and serviceability of reinforced concrete structures, particularly in marine environments. Geopolymer concrete (GPC) reinforced with corrosion-free glass-fibre-reinforced polymer bars is ideal for projects such as bridge piers in coastal zones where corrosion is severe. This paper reports on an examination into the behaviour of this novel construction material under axial, combined and flexural loading and validation of a numerical model of the material. To this end, 11 GPC specimens constructed with various stirrup spacings were subjected to a range of loading conditions. The concrete was modelled using the widely used concrete damage plasticity model and linear elastic behaviour was used for the fibreglass bars and stirrups. The predicted axial load-deflection responses were in close agreement with the experimental data, especially for concentrically loaded columns. The load capacities of eccentrically loaded columns and beams were slightly overpredicted by the model due to a tendency of the fibreglass stirrups to open up prematurely.