| In recent years,China ’s labor costs have continued to increase.Problems such as environmental pollution and sustainable development of construction sites caused by traditional reinforced concrete structures need to be solved urgently,and fabricated reinforced concrete structures have factory production,high product quality,and short construction cycles The advantages of less wet work on site,energy saving and environmental protection have met the requirements of sustainable development in today’s society,and have attracted more and more attention from the engineering community.In the current prefabricated concrete frame structure,nodes and connection forms are important factors affecting its mechanical performance.Designing reliable and reasonable joints and connections is the key to improving the performance of prefabricated structures.This article combines the advantages of large rigidity and bearing capacity of the steel structure,good local and overall stability,good seismic performance,and the advantages of fabricated reinforced concrete structures,and designs an assembled structure with beam connections at the beam and column joints.In this paper,a total of 7 beam-column joint test specimens are designed,one of which is a common cast-in-place beam-column joint test specimen and the remaining six are fabricated beam-column joint test specimens.The dissertation details the design and fabrication process of fabricated beam-column joint test specimens,and describes and explains in detail the test scheme,the layout of the test equipment,and the experimental process and phenomena.The failure phenomenon of the test piece was photographed,the crack development and distribution of the test piece were plotted,and the similarities and differences between the assembled beam-column joint test piece and the ordinary cast-in-place joint test piece during the test piece failure process were analyzed and the shear span.The effect of the ratio of the profile flange width and the distance between the profile connection and the column surface on the crack development and distribution of fabricated joint test specimens.This paper compares and analyzes the test results of seven test specimens under repeated low-cycle effects.Based on the data recorded in the test,the hysteretic curve,skeleton curve,ductility,stiffness degradation,and energy dissipation capacity of each test specimen are obtained.The performance and the seismic performance of each specimen are analyzed,and the influences of the shear-span ratio,the width of the profile flange and the distance between the profile connection and the column edge on the seismic performance of fabricated beam-column joint specimens are summarized.The comparative analysis of the test results shows that the new fabricated beam-column joint test piece has a much larger ultimate bearing capacity than the ordinary cast-in-place joint test piece because of the use of excellent mechanical properties of steel connection.The cracks in the concrete in the core area of the joints and the concrete on the columns are less developed,and the crack development and failure locations appear at the beam end,which fully reflects that this new type of assembled beam-column joints meets the seismic requirements of strong columns and weak beams,and strong nodes and weak members Moreover,the ductility coefficient of fabricated joint specimens is also larger than that of cast-in-place joint specimens.From this,it can be seen that fabricated beam-column joint specimens connected by profiled steel have good seismic performance. |
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