Effect of intumescent paint coating on mechanical properties of FRP bars at elevated temperature

Abstract

This paper investigates the influence of intumescent paint on the performance of FRP bars subjected to low (25–450 °C) and severe (450–800 °C) elevated temperatures. In this research, glass and carbon FRP bars with epoxy resin and coated with nitrogen-based intumescent paint were used. In addition to the temperature effects, a variety of FRP bar diameters were employed to determine its effect on the tensile behavior of FRP bars in the presence of intumescent paint. Further, Bayesian regression methods and ANOVA (ANalysis Of VAriance) were applied on the results to develop a predictive model form and quantify the contribution of the variables in the tensile performance of FRP bars, respectively. The results revealed that the intumescent paint prevented the degradation of the mechanical properties of FRP bars significantly, up to 30% of GFRP bars tensile load capacity, at the temperature range 350–600 °C.