Investigation of the behavior of reinforced concrete cylinders with glass fibers under high temperatures

Articles in Press

Document Type : Original Article

Authors

Golriz Gharaei

Amir Darvishi

Hadi Ziaadiny

Amirhosein Raisszadeh

Engineering Faculty, Vali-e-Asr University, Rafsanjan, Iran.

10.22067/jfcei.2026.96463.1391

Abstract

Fiber-reinforced polymers (FRP) are widely used for strengthening and rehabilitating reinforced concrete (RC) structures due to their high tensile strength, corrosion resistance, light weight, and durability, offering a more efficient alternative to conventional techniques that increase structural mass and member dimensions. Despite these advantages, fire represents a critical hazard for FRP-confined concrete, as elevated temperatures can deteriorate both the concrete matrix and the polymeric resin, thereby reducing the effectiveness of confinement. Although FRP systems are increasingly applied in structural retrofitting, limited research has addressed the residual mechanical performance of FRP-strengthened concrete after exposure to high temperatures. This study investigates the influence of elevated temperatures on cylindrical concrete specimens confined with glass fiber sheets. Twelve concrete cylinders (100 mm in diameter and 200 mm in height) were wrapped with two layers of glass fiber reinforcement, cured, and then exposed to temperatures of 100°C, 200°C, and 300°C for one hour before being gradually cooled to room temperature. The specimens were subsequently tested under uniaxial compression. The results demonstrate that glass fiber confinement enhances compressive strength, while increasing temperature levels reduce this strength gain compared with unheated control specimens.

Keywords

Fire

Heat

Composite Fibers

Concrete

Fire Damage

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