Experimental Investigation Into the Fire Performance of GFRP-Reinforced Concrete Beams

Abstract

A Master of Science thesis in Civil Engineering by Mohammed Al Dawood entitled, “Experimental Investigation Into the Fire Performance of GFRP-Reinforced Concrete Beams”, submitted in June 2025. Thesis advisor is Dr. Farid Abed. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This thesis presents an experimental investigation into the fire performance of GFRP-reinforced concrete beams, focusing on flexural capacity, bond behavior, and the effectiveness of fire-protective strategies. Full-scale beams were subjected to standard fire exposure per ASTM E119, with key variables including fire protection type (intumescent paint, cement-based mortar), anchorage zone length, and lap splice detailing. Results show that unprotected GFRP-reinforced beams exhibited rapid degradation in flexural capacity, with ultimate moments dropping by over 40% after 180 minutes of fire exposure, and bottom bar temperatures exceeding 550°C—well above the glass transition point of 110°C. Beams protected with Sikacrete 213F mortar showed a maximum internal temperature of only 150°C, displaying minimal spalling or cracking. Intumescent-painted beams offered partial protection, with bottom bar temperatures around 450°C and moderate structural deterioration. Beams with reduced anchorage zones and shorter lap splices displayed an increase in deflection. Comparative analysis confirms that only cementitious coatings consistently preserve structural integrity. Additionally, results show that an increase in lap splice length retains approximately 84% of the moment capacity of a continuously reinforced beam, whereas a shorter lap splice length does not. Additionally, during fire exposure, longer lap splice exhibits similar behavior to continuously reinforced beam. These findings highlight the vulnerability of GFRP systems to fire and support the development of targeted fire-resistance guidelines for the safe design and application of GFRP-reinforced concrete elements.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE