Tension Stiffening Behavior of GFRP-Reinforced Concrete

ABSTRACT

This paper presents an experimental study into the structural response of Glass Fiber Reinforced Polymers Reinforced Concrete (GFRP-RC) tension members. The influence of concrete strength, reinforcement ratio and bar diameter on tension stiffening is investigated by testing elements in direct tension. Using bars specially manufactured with internal strain gauges, typical strain patterns occurring between cracks during direct tension tests were measured and bond stresses derived, thereby obtaining the information for modeling tension stiffening behavior of GFRP-RC. An increase in the tension stiffening behavior with decrease in reinforcement ratio and increase in concrete strength was observed. No appreciable change in tension stiffening was recorded with changes in bar diameter at constant reinforcement ratio. This paper also discusses the limitations that may be encountered in modifying current models to represent the tension stiffening effect of GFRP-RC.

Keywords 

bar diameter; bond (concrete to reinforcement); GFRP-RC; reinforcement ratio; strain patterns; tension stiffening