Serviceability analysis of concrete beams with different arrangements of GFRP bars in the tensile zone

Abstract

Extensive experimental investigations were carried out to investigate the serviceability (deformations and crack opening width) of fiber–reinforced polymers (FRP) reinforced concrete members. However, most of the tests were limited to conventional arrangement of bars in a section. Considering glass fiber–reinforced polymer (GFRP) bars (one of the most frequently used types of composite reinforcement), this study experimentally and analytically investigated the serviceability behavior of beams with different arrangements of reinforcement bars in the tensile zone. With particular emphasis on tension-stiffening and bond behavior, the experimental program consisted of full-scale beams and bending bond specimens. The tests revealed specific features in the behavior of the beams due to distribution of tensile bars in three layers or enlarging the cover. A numerical procedure, based on local interaction of reinforcement and surrounding concrete, was applied for serviceability analysis. Several bond stress-slip models were employed in the numerical analysis. Despite the satisfactory prediction of crack opening and deformations in general, neither of the bond models was able to give accurate results for all the beams.