Influence of Gross-to-Cracked Section Moment of Inertia Ratio on Long-Term Deflections in GFRP-Reinforced Concrete Members

Abstract

An experimental study was conducted to evaluate the effect of the gross-to-cracked section moment of inertia ratio Ig:Icr on the long-term deflection multiplier for glass fiber–reinforced polymer (GFRP) reinforced concrete beams subjected to sustained loading. Ten beams (eight GFRP-reinforced beams and two steel-reinforced beams) were maintained under a constant sustained service load for nearly three years. Long-term deflections were monitored on each beam over the duration of the test. Based on the results, the long-term deflection multiplier was found to be related to the gross-to-cracked section moment of inertia of the beam cross section. These trends were further confirmed by an examination of results published by other researchers and from an analytical study based on simple deflection models.