Experimental Investigation of the Effects of Insulation Materials and Concrete Strength on Temperature Transitions in FRP Reinforced Structural Elements Under High Temperature

Abstract

There are serious concerns about the preference of Fiber Reinforced Polymer (FRP) bars, which are widely used in buildings, in reinforced concrete structures due to their sensitivity to high temperatures. Especially in cases where the glass transition temperature of FRPs exceeds, losses occur in the mechanical and physical properties of FRP bars. Fire insulation materials used in reinforced concrete structures are of great importance in protecting the building elements against high temperatures. Insulation materials protect concrete and rebars against high temperatures and prevent strength reductions. In this study, the effects of different fire insulation materials and concrete strength on temperature transitions in FRP reinforced concrete structural elements were determined by experimental studies. The protection performances of the concrete and the rebars in the concrete against the effects of temperature were investigated. The study was carried out in 500 oC environments that can reach the glass transition temperature (80-110 oC) of FRP bars. Ambient temperatures, concrete surface temperatures and reinforcement surface temperatures in the concrete were measured depending on time with the experimental setup created. As a result of the study, it was determined that fire insulation materials are more effective than concrete strengths. In the effect of ambient temperature on the concrete surface, while the rock wool allowed a temperature transition of 13%, this value was 22% in glass wool and 26% in red drywall.