Calculation And Analisys Of Fire-Resistance Performance Of Strengthened Concrete Flexural Members With CFRP Laminate

The current"Technical specification for strengthening concrete structures with carbon fiber reinforced polymer laminate"(CECS146:2003) only presents a qualitative application rule for fire-resistance measures for strengthened concrete flexural members with carbon fiber reinforced polymer (CFRP):"Applied fire-resistance materials and methods should make strengthened building reach the required fire resistance rating". However, the technical specification doesn't institutes a specific guideline for fire-resistance design of strengthened concrete structural members with CFRP laminate. Therefore, the fire-resistance performance of strengthened concrete flexural structural members with CFRP laminate is calculated and analyzed in the paper. The main contents are as follow:The research in China and around on the mechanical performance of concrete and mild steel bar subjected to fire are summarized and analyzed, and research status of the temperature field is introduced. All these provide basic material for research on the fire-resistance performance of strengthened concrete structural flexural members with CFRP laminate.The fire-resistance measures of strengthened concrete structural flexural members with CFRP laminate in experiments and engineering application are summarized, and the measures to improve fire-resistance performance of strengthened concrete structural members with CFRP laminate by thick fireproofing coatings is selected. The temperature field in strengthened concrete structural members with CFRP laminate by thick fireproofing coatings is calculated using ANSYS software, and the relationship between the thickness of fireproofing coatings and the effect to prevent heat conduction.An analytical program for calculating flexural carrying capacity of strengthened concrete structural flexural members with CFRP laminate at elevated and at normal temperature is developed. The safety factor expression of strengthened concrete structures with CFRP laminate at normal temperature corresponding effective loads effect is obtained. Based on the safety factor expression, lots of calculation for flexural carrying capacity of strengthened concrete flexural members with CFRP laminate subjected to fire with different improvement of load carrying capacity, section dimension, and thickness of fireproofing coatings is accomplished. The key parameters which influence the fire-resistance performance of strengthened concrete flexural members with CFRP laminate is summarized, and the fire endurance of the members with different parameters is obtained, and the proposition for the thickness of fireproofing coatings for strengthened concrete structural flexural members with CFRP laminate subjected to fire is proposed.