Numerical modelling on fibre reinforced polymer strengthened reinforced concrete beam at elevated temperature

Abstract

This research presents the study of on insulated Fibre Reinforced Polymer (FRP) strengthened Reinforced Concrete (RC) beam at elevated temperature using finite element program, ABAQUS. The study aims to investigate effects of different concrete cover thickness of insulated FRP strengthened RC beam when exposed to elevated temperature. The modelling consists of insulated and non-insulated FRP strengthened simply supported RC beam with a rectangular size of 200mm x 300mm. The beam modelled with different concrete cover thickness of 15 mm, 25 mm, 30 mm and 35 mm, and strengthened using Carbon Fibre Reinforced Polymer (CFRP) with U-shaped insulation. The beams were exposed to standard fire exposure of ISO 834 for the duration of two hour. The verification was carried out based on the previous experimental test results. It has been found that rebar temperature decreases with the increment of concrete cover and was significant for the non-insulated FRP strengthened beam compared to the insulated FRP strengthen RC beam where the max rebar temperature of 285°C and 622°C for model I_C15 and NI_C15 respectively. The thermal-mechanical response resulted in a maximum deflection of 21 mm and 83 mm for I_C15 and NI_C15 respectively at the temperature of 945°C.The results from this study shows that concrete cover contributes to the fire resistance of structure for FRP strengthened beam at elevated temperature and affects on the overall performance of structure especially for non-insulated beam.