RESEARCHES ON THE FIRE RESISTANCE DESIGN METHOD FOR RC BEAMS STRENGTHENED WITH CFRP LAMINATES

摘要

Externally coating of fireproof materials for reinforced concrete (RC) structures strengthened with carbon fiber reinforced polymer (CFRP) is widely used in actual engineering.In order to research the design method against fireproof coating's peeling off in fire, finite elements analysis and construction measures experiments were carried out in this paper.The finite elements analysis taking the different fireproof materials, thickness of coating, loading ratio, CFRP strengthening ratio and depth-span ratio as the parameters, the specimen 's mid-span deflection under fire as the output target were carried out using finite elements software ANSYS.The results showed that the thickness of coating, loading ratio and depth-span ratio were the main factors influencing the fire resistance performance of RC beams.A simplified formula to calculate the thickness of fireproof coating was also proposed based on the analysis data.Tests on actual structural members were carried out in this project to optimize the design of fireproof RC beams strengthened by means of CFRP laminates.We tested different fireproof materials including thick fireproof coating, ultra-thin fireproof coating, fireproof panel and normal cement mortar with different construction measures respectively.Based on the experimental results, the different construction measures for thick fireproof coating, ultra-thin fireproof coating and cement mortar were presented and recommended in actual engineering applications.