Preliminary Research On Fireproof Methods Of CFRP-strengthened RC Beams

Nowadays, CFRP-strengthening (Carbon Fiber Reinforced Polymer-strengthening) method is widely used in China. However, the performance of CFRP-strengthened structures in fire is so bad. Researching on fire protection technology for CFRP-strengthened structures is urgent.Based on the investigating of material properties of CFRP at elevated temperatures, a solution to the fire protection problem is given. According to the patterns of CFRP-strengthening structures and the traditional fire protection measures, the principle of choosing fire protection for CFRP-strengthened structures is given, all the measures are compared one another. Based on a general review on the achievements obtained by foreign and Chinese researchers, thermal and mechanical properties of concrete, reinforcing bar and CFRP at elevated temperatures are presented.Two specimens of CFRP-strengthened beams with fire protection measures are designed and tested in fire in Far East Fire Testing Center. The testing results are analyzed, and the effects of fire resistant coating are examined, and the layout of fire resistant coating is analyzed.A numerical model considering the moisture migration and debonding of fire resistant coating layer and making use of the general finite element software-ANSYS is presented. The effectiveness and reliability of the approach is validated by the good agreement between the theoretical results and the experimental data. A numerical model to simulate the structural response to fire of CFRP-strengthened structures is set up. By the comparison of the theoretical results and the experimental data, the main cause of the deflection of the beams is analyzed.