The bond between glass-fibre-reinforced polymer bars and ultra-high-strength concrete

This paper presents the bond characteristics of sand-coated, glass-fibre-reinforced polymer bars in ultra-high-strength concrete. A total of 216 pullout specimens were tested with variable parameters: bar diameters of 15·9 and 19·1 mm; bar embedment lengths of three, five and seven times the bar diameter; standard and high bar moduli; and concrete strengths of 129, 145 and 175 MPa. The influences of these parameters on bond strength, load–slip characteristics and failure modes are described. The bond stresses predicted from various North American codes are compared with those obtained from experiments.