The Application Study In Strengthening Concrete Structures With Carbon Fiber Reinforced Polymer Laminate

Due to the causes of building material aging, load increasing, partial structure damaging, building's function changing, defects in design and construction, and so on, covering buildings, bridges and tunnels, etc. which were built in the 90s, the load-bearing capacity of original structures cannot meet the new requirements. If we demolish all the existing buildings and reconstruct new ones, that would undoubtedly increase the burden of the society, and cause huge waste of resources and environmental pollutions. Therefore, the strengthening and repairing for old buildings have become increasingly important. Using the carbon fiber reinforced polymer (CFRP) for strengthening and repairing concrete structure has been becoming the emphasis of research in engineering which is effective and the cost can be saved. This thesis is comprehensively, systematically made on the relevant theory and practical problems of the carbon fiber reinforced polymer strengthening from CFRP's behavior, mechanical analysis of flexural strengthening, shear strengthening, compression strengthening and seismic strengthening to design calculations in engineering cases.According to the assumption of plane section, formulas of flexural strengthening of T-sector are deduced based respectively on《Design code for strengthening concrete structures》(hereinafter referred to as design code) and《Technical specification for strengthening concrete structures with carbon fiber reinforced polymer laminate》(hereinafter referred to as technical specification),then analysis and comparison of the formulas of the two flexural strengthening of T-sector are made using engineering cases.Using the calculate function of EXCEL, computing programmes for flexural strengthing of rectangular-section, shear strengthening of beam and column, seismic strengthening of column are made based on《technical specification》and those for flexural strengthing of rectangular-section, shear strengthening of beam and column, compression strengthening of column, strengthening of column with large eccentric compression load, seismic strengthening of column and strengthening of tension member are made on《design code》,and the reliabilities of the computing programmes is testified with engineering cases.With these programmes, after inputting basic parameters, the results are directly input out and the work efficiency of strengthening design is greatly improved.《Design code for strenghthening concrete structures》(GB50367-2006) and《Technical specification for strengthening concrete structures with carbon fiber reinforced polymer laminate》(CECS 146: 2003) are both our country's design criterions of CFRP strengthening, the former is national code and the latter is industry regulations, so it is the first problem that need be solved by the designers of strengthening. This thesis has analyzed the advantages and disadvantages of the two criterions' formulas of flexural strengthening and shear strengthening in combination with engineering cases, and suggestions on the selection of design standard are recommended.