Temperature Distribution And Performance Study About CFRP Reinforced Concrete Beam Under Extremely Hot

As the growth of the building using time, parts of it start to degenerate and the bearing capacity of each component declines a lot. The use of carbon fiber reinforced polymer(CFRP) has become more and more widely because of it’s high tensile strength and saves using space as well as easy to be constructed. Many combustible construction materials had been used in construction decoration with the development of building materials. Structure fire had become a highest frequency threat to human life and property. Calculate the bearing capacity of reinforced concrete beam in different times under fire can estimate the duration of the building as well as the time for people to get away from the burning building. This paper used finite element software(MARC) to build an three-dimensional numerical analysis model of CFRP reinforced concrete beam. Get the rule of temperature field distribution. The results shows that CFRP has no fire protection ability, the distribution forms areas of temperature around reinforcement cages. With no fire protection layer, temperature of beam cross section rises rapidly and strength of longitudinal reinforcement depredates more than a half within a short time(30min), Compared to no fire protection layer, with the thickness of 10 mm, beam Cross section temperature can still be controlled under 400℃ when loaded 180 min later, the time of losing 30% and 50% strength of longitudinal reinforcement on the outside extend about 1.5h and 2h separately, and all extend about 2h for longitudinal reinforcement in the middle. While the thickness of fire protection layer is 40 mm, strength of longitudinal reinforcement remains at 95% throughout the loading procedure. This paper calculated the flexural bearing capacity of normal section of beam reinforced by carbon fiber polymer in different time under fire by using the cross-section temperature field calculated before. The results can Provide certain reference for the engineering design or construction.