The Research Of Rectangular Column Reinforced By Carbon Fiber Based On Secondary Load

Reinforced concrete structure is in central position in China's industrial and civil buildings, the design standards is 50 years, so at present there are quite a few buildings in the old age; the building were damaged by environment, such as the corrosion of acid rain,fire and earthquake. Some buildings change the building function or the load increases, so the buildings must be strengthened in order to make these buildings safe. The technology strengthened with CFRP has been widely used in many fields, but immature theory in many aspects and expensive material influence its application and promotion.The author consults relevant information and documents, and understands the research situation and development prospect of reinforced concrete structure by CFRP, and summarizes the carbon fiber reinforced theory currently. The research has the following characteristics:1) the research are more about flexural components such beam and board; but research and experiments about compressive components are relatively fewer.2) the research based on initial load are mature, and have relevant specification and calculation formula; but the research based on secondary load are fewer, the once load could damage the components, so it's necessary to consider the effect of initial load, otherwise you may overstate the reinforcement effect.This paper does the following job on the basis of above all:1) This paper discusses the mechanism of rectangular column strengthened by CFRP, and also discusses some factors that influence the effect of rectangular column strengthened by CFRP; according to the analysis of material nonlinearity, the paper selects finite element of various materials and set related parameters, and using birth and death of element for secondary load.2) The paper also does simulated experiment for small scale models and actual percentage models, and proves influence of the size effect for reinforcement effect.3) the author does simulated experiment of axial compressive column strengthened by CFRP that based on secondary load, the experiment main inspects the influence of bearing strengthened by CFRP caused by different sizes of initial load. The results show that:when the initial load is less, it influences the results less; when the one-time load is large, it influences the ultimate bearing capacity strongly. 4) The paper does simulated experiment of eccentric compressive column strengthened by CFRP, it main inspects the influence of eccentricity for the ultimate bearing capacity. The results show that:with the increase of eccentricity, the incremental value of bearing also increases.5) The author does simulated experiment of eccentric compressive column strengthened by CFRP based on secondary load, it main inspects the influence of bearing of eccentric compressive column strengthened by CFRP caused by different sizes of initial load. The results show that:when the initial load is small, the ultimate bearing capacity of the column strengthened by CFRP reduces greatly; with the increase of the initial load, the ultimate bearing capacity also reduces.