The present research addresses an issue which is a major concern about the use of fiber reinforced polymers (FRP) in retrofit and strengthening applications. This paper presents an experimental investigation of the effectiveness of different fire protection materials and techniques on the efficiency of concrete axial members strengthened by FRP and subjected to high temperatures such as in the case of fire. Three locally available and economic materials are investigated: ordinary Portland cement mortar, Perlite and Vermiculite. These were applied with different thicknesses over FRP wrapped concrete specimens and subjected to elevated temperature in a closed furnace. For each case, variation of the temperature on the underlying concrete surface and the ultimate load carrying capacity were studied in order to explore and compare the effectiveness of these protection layers. Protective layers were applied over concrete cylinders strengthened using glass or carbon FRP wraps and subjected to elevated temperature to investigate the effect of fire protection materials on ultimate axial load carrying capacity and mode of failure. The results demonstrated that cylinders strengthened with FRP and protected using perlite mortar and ceramic fiber resulted in significant fire protection compared to unprotected FRP strengthened cylinders. |
