The paper evaluates extent of corrosion damage to composite glass-fibre fabric reinforcement in environment simulating concrete pore solutions (pH 12.6, 13.0, 13.5) and carbonated concrete contaminated with chlorides (pH 8.1 + Cl-) using the FT-IR and SEM/EDS techniques. Also, the effect of corrosion damage on tensile strength of segmented glass fibre as well as the presence of specific protective organic coating on glass fibre were studied. The results demonstrate local corrosion damage of samples at pH 13.5 and on the other hand high stability in environment simulating carbonated concrete and carbonated concrete contaminated with chlorides. The study also suggests unevenness of organic coating with occurrence of localized porosity which is related to aforementioned corrosion damage. Corrosion damage in FT-IR spectra manifests by changes in peaks signalling hydrolysis of protective organic coating and occurrence of peaks suggesting presence of Ca2+ rich corrosion products.