Study On Fire-resistance Performance Of Reinforced Concrete Structures Strengthened With Steel Tube-concrete-CFRP

FRP material because of its high strength, light weight, good durability, 'insulation, acid and alkali, corrosion resistance!' series of advantages are widely used in the field of modern industry,which greatly promotes the development of modern industries such as navigation, aerospace,medicine, machinery and other industrial fields. At the same time, the excellent properties of FRP materials have greatly promoted the development of the building structure strengthening and repairing in the field of civil engineering, which is affected by the earthquake disaster and fire. With the rapid development of FRP material, the application of FRP in the field of civil engineering has begun to conduct in-depth research, and explore the performance of the disaster in the way of experiment and numerical simulation: FRP materials superior performance, but poor high temperature performance, easy to burn by the fire, a serious shortage of fire resistance performance, At high temperature, the disadvantage of poor bonding performance between FRP materials and components further limits the development of FRP materials in the field of civil engineering.As mentioned above, FRP material is high temperature resistant and fire resistant performance is insufficient. Therefore, in recent years, many of FRP materials testing and analysis program, and increased fire resistance performance of FRP materials research and analysis, also put forward a series of High temperature protection measures of FRP materials.This article is a reference to many scholars study based on the theory, this paper is to further expand the research on the new SCCC structure, which is proposed by Professor Liu Yongjun.The research is carried out to explore the application of the damaged structure in the fire test.The subject extension: thin steel tube- concrete- CFRP composite reinforced concrete column;As is known to all, the concrete is hot inert material, its thermal conductivity is low, similar to the fire properties of special fireproof material, under the high temperature internal temperature of concrete component is surface temperature is extremely low, can play the role of good thermal insulation, fire-retardant, this paper takes full advantage of the fire properties of concrete; For not subjected to significant damage to the building structure, or after long structural column surface cutting hair fill level processing, and then sticking CFRP cloth to repair structural members; Objective: to enhance the bearing capacity and save the economy. Considering the disadvantages of CFRP, the fire resistance of can be improved by adding a large size of steel tube,and filling the concrete filled with steel tube in the CFRP layer, make full use of the excellent fire resistance of concrete to improve the fire resistance of the whole structure. The subject from the fundamental to make up for the CFRP materials resistant to high temperature performance disadvantage, outsourcing steel but also an effective solution to the concrete material at high temperature is easy to peel characteristics exist. And also steel, concrete and CFRP sheets under the condition of high temperature and bearing capacity of the coexistence of synergy can effectively improve the integral component of the bending performance.The main contents of this paper: Firstly, the performance of the reinforced concrete column is analyzed by high temperature combustion furnace, and the related performance of the buildingstructure is simulated; The performance of the components under the action of fire and axial pressure is analyzed, and the temperature and time variation of the components in the process of the test are recorded, and the process of data changes in the formation of a change curve analysis.In the process of experiment, the mechanical properties of the component materials at high temperature decreased rapidly with the increase of temperature. In the high temperature, the large area of concrete facing layer was dropped, the protective layer and the steel bar were peeled off, and there is no serious damage due to the protective layer. According to the temperature field of each section of the test, great temperature difference between outside to inside, reinforced section temperature reaches 400 ? ~ 600 ?, the minimum core temperature,but also reached about 100 ?.After high temperature, For natural cooling conditions of the members of the reinforcement and repair, repair method using steel tube- concrete-CFRP composite reinforcement technology,the formation of new composite reinforced with anti-fire test structure of reinforced concrete column as heated situation in the international standard application. In the process of anti fire test of the whole structure, the damage of the structure under the action of high temperature and load is described in detail, and the failure of the reinforced concrete column is compared with that of the fire test, through strengthening the internal temperature field of the component, the superior performance of the composite reinforcement structure is proved. Based on a composite reinforcement structure under fire resistance performance of RC members temperature performance comparative analysis found that a composite reinforcement structure greatly enhanced fire performance of FRP materials while steel, concrete, CFRP three synergistic effect enhances the structural ultimate bearing column force! Compared to reinforced concrete members under fire performance, there was no significant damage to the case of composite reinforcement structure, the overall component has no great damage, and its fire resistance performance is greatly improved.