Performance of reinforced beam strengthened with carbon fiber reinforced polymer sheet at elevated temperatures

The behaviour of reinforced concrete beam strengthened with carbon fiber reinforced polymer sheet at elevated temperature is investigated. To understand Fire performance of reinforced beam strengthened with carbon fiber reinforced polymer finite element method is adopted. Nine models with different concrete cover thickness, 20, 30 and 40 mm and strengthened with 1.2 and 2.4 mm thick CFRP sheet was developed by using commercially available software ‘ANSYS’. The models were exposed to elevated temperature ranging from 100°C to 800°C at an increment of 100°C with 30 minutes of retention period. The unstrengthened beams are compared with the strengthened beams with 1.2, 2.4 mm thick CFRP sheet. Temperature variation along the depth of beam, maximum deflection, stress and strain were obtained from the analysis. The analysis shows that, for un-strengthened beam with 20 mm concrete cover the tension reinforcement get exposed to temperature at faster rate than 30 and 40 mm concrete cover beam, which makes beam member, fail early. Results illustrate that, concrete cover and CFRP sheet are important parameters to increase the fire endurance of beam.