| The load bearing member of RC frame would be failure under accident loads and could not support the upper member,which would cause local collapse and the local collapse could result in disproportionate progerssive collapse due to the integrity and coherence of construction.How to enhance their progerssive collapse’s abilities had became one of research hotspots of engineering reinforcement.Considering the good characteristics of CFRP sheets,such as strong tensile strength、no additional loads、corrosion resistance and so on,selecting the CFRP sheets to enhance the structures had been becoming a trend and this reinforcement method had a good prospects in enhancing the strength of structures.In oredr to study the strengthence to improve the progressive collapse behavior of RC substuctres which reinforced by CFRP sheets,two RC beam-column sub-structures were tested and analysied in this paper.The primary contents are demonstrat ed as follows:1.Two same single four-span RC beam-column sub-structures were tested by pseudo-static testing,which one group without reinforcement and the other group was reinforced by CFRP sheets.Through the comparison of the failure column’s displacement-load curves、reinforcement strain of critical section of beam、the failure mode of specimens、ultimate bearing capacity of structure and ulimate deformation,studying on the effect of CFRP sheets on the progressive collapse resistance of RC beam-column sub-structure.2.According to the method of resistance source in the process of continuous collapse of the structure under the condition of no reinforcement and reinforced by CFRP sheets,the simplified calculation formulas which were used to calculate the bearing capacity took place in the stage of flexural action、compressive arch action and catenary action were put forward in the paper,and the calculated results are agree able with the test results by comparsion.3.Through the numerical analysis of these two sprcimens by the finite element software OpenSees,the analysis results were found similarly to the actual results.On this foundation,the influence of reinforcement layer on bearing capacity is studied and the results show that there is no linear relationship between the reinforcement layer and the bearing capacity. |
