BOND BEHAVIOR OF GLASS FIBER-REINFORCED POLYMER BARS EMBEDDED IN CONCRETE

Abstract

This study investigates the bond behavior of glass fiber-reinforced polymer (GFRP) bars embedded in concrete, compared to steel reinforcement at identical embedment lengths. It also analyzes the optimal development length required for GFRP bars to achieve maximum tensile strength under ultimate conditions without bond failure. The experimental program involved embedding GFRP bars at lengths ranging from 15 to 50 centimeters (cm) and steel bars at lengths ranging from 15 to 30 cm into cylindrical concrete specimens with a diameter of 15 cm, a height of 50 cm, and compressive strengths of 240 and 320 kilograms per square cm. Pull-out tests were conducted to evaluate maximum bond strength, slip behavior, failure modes, and constants for calculating the optimal development length of GFRP bars. The findings provide insights into bond behavior and optimal development length, serving as guidelines for safe, efficient design of concrete structures reinforced with GFRP bars.