Evaluation of Physiogeometrical Properties of Glass Fiber Reinforced Polymer Bars Manufactured in Ghana

Abstract

Glass fibre-reinforced polymer (GFRP) bars are increasingly considered alternatives to steel reinforcement because of their corrosion resistance, high strength-to-weight ratio, and electromagnetic neutrality. However, the physiogeometrical properties of GFRP bars manufactured in Ghana have not been adequately documented. This study evaluated locally manufactured GFRP bars with nominal diameters of 10, 12, and 16 mm. The investigated parameters were cross-sectional area, equivalent diameter, rib height and spacing, fibre mass fraction, and moisture absorption after 24 hours. Five specimens from each bar size were examined for each test category using procedures referenced to ACI, ASTM, Canadian, and Indian standards. The measured equivalent diameters and cross-sectional areas were slightly greater than the nominal values, although the differences were not statistically significant. All specimens were sand-coated and helically wrapped, with bar-size-dependent variations in rib geometry. Mean fibre mass fractions ranged from 77.09% to 78.07%, exceeding the minimum limits used for comparison. Mean moisture absorption after 24 hours was 0.109% for 10 mm bars and 0.135% for 12 mm bars, both below the 0.25% comparison limit. The 16 mm bars recorded 0.277%, which was 10.8% above that limit. Overall, the tested bars generally satisfied the evaluated physiogeometrical requirements, although the higher moisture uptake of the 16 mm bars indicates the need for further assessment of manufacturing consistency and long-term durability.