Évaluation de la durabilité en milieu alcalin des armatures à base de fibres de verre pour les structures de génie civil en béton armé

Abstract

Durability of glass fiber reinforced polymer (GFRP) rebars manufactured by three different companies has been evaluated. The GFRP rebars are made from different matrices, glass fibers and manufacturing processes. The rebar specimens have been exposed to various alkaline environments, such as simulated pore water solution (pH = 12,8) and moist concrete. The specimens were subjected to different sustained loads (25-65% of their ultimate tensile strength), using two different loading systems. Time to rupture or residual tensile strength, as applicable, has been determined. Additionally, thermal gravimetry (TG), differential scanning calorimetry (DSC), light microscopy (LM), scanning electronic microscopy (SEM), energy dispersive X-ray (EDXA), X-ray elemental mapping (XEMA), infra red spectroscopy (IR) and absorption measurements have been carried out to understand the stress corrosion mechanism of GFRP rebars exposed to concrete. Tests have also been performed on the neat matrices in order to determine the effect of the alkaline environments on the degradation behaviour of the polymer resins used in the rebars."--Résumé abrégé par UMI