Study On Seismic Performance Of The Prestressed Prefabricated Recycled Aggregate Concrete Frame

With the rapid development of society,the contradiction between human demand for building materials and lack of resources is becoming increasingly serious,which requires the replacement of new materials and the innovation of construction methods to meet the demand.RAC has the advantages of low energy consumption and green sustainable development,and has been deeply researched and gradually promoted at home and abroad.In order to realize the road of building industrialization at an early date,China encourages new buildings to adopt prefabricated structure.The prestressed prefabricated frame structure is currently relatively mature in research,and it can meet the needs of seismic fortification in practical engineering.However,the research on the application of RAC to prestressed prefabricated frame structures started late,and there is a lack of systematic understanding under the action of seismic loads,which limits the forward development of RAC.In this paper,the experimental research and finite element analysis of the prestressed prefabricated RAC frame are carried out,and the seismic performance of the structure is fully understood through these two methods.The main work and conclusions carried out are as follows:(1)Four-layer prestressed prefabricated RAC frames with a replacement rate of recycled aggregates of 0%,30%,50%,and 100% were subjected to horizontal and lowcycle repeated loading tests.After analysis,the seismic performance of the frame under different RAC formulas can be obtained.The results show that during the loading process,the failure characteristics of the four frames are basically similar.First,plastic hinges appear at the beam end,and finally plastic hinges appear at the bottom of the column,and the frame loses its bearing capacity.Ordinary concrete frames are superior to other frames in terms of energy consumption and ductility.As the replacement rate of recycled aggregates increases,energy consumption and ductility will gradually decrease.In terms of residual deformation and bearing capacity,the values of the frames are approximately the same,and the properties of RAC are similar to ordinary concrete in this respect.(2)Based on the ABAQUS finite element software,the numerical analysis of the seismic performance of the 4 prestressed prefabricated RAC frame is carried out.The results show that the simulated failure characteristics of the RAC members,the reinforcement framework and the steel strands can correspond well with the test results.The hysteresis curve is in good agreement with the test hysteresis curve.Both the force and the direction can have a small error with the test.This shows that the selection of material constitutive model and the modeling method can be in line with the actual situation to a certain extent during the modeling process,and the model has high reliability.(3)Based on the previous finite element simulation,five parameters,prestress value,axial compression ratio,column reinforcement ratio,steel bar strength and RAC strength,were selected to analyze the seismic performance of the prestressed prefabricated RAC frame.The results show that as the prestress value increases,the initial stiffness of the structure becomes slightly larger and the stiffness degrades slowly,but the overall difference is not large;with the increase of the axial compression ratio,there is no hysteretic performance for the structure before reaching the maximum peak load too much change,but the unloading strength degradation slows down and the stiffness becomes larger;the effect of increased column reinforcement ratio and increased reinforcement strength on the seismic performance of the frame is similar,and the frame has been greatly improved in terms of bearing capacity,energy consumption,ductility,etc.;As the strength of RAC increases,the bearing capacity of the frame in the early stage has been greatly improved,but when the displacement angle is after 1/50,the impact on the hysteretic performance is small.(4)Based on the ABAQUS software,the seismic performance of the selfcentering prefabricated RAC frame is also numerically analyzed.The results show that: using 4 kinds of RAC formulas,the 4 sets of self-centering RAC frames have good selfcentering ability,and there is little difference in damage characteristics and hysteretic performance.The damage of the RAC of the structure is mainly concentrated on the corbel and the beam end.The damage of the column is very small,the overall damage is controllable,and it is easy to repair after the earthquake.Reinforcement stress is concentrated at the beam end,and the steel strand has good deformation ability,which can make the column and beam end rotate,and enhance the energy dissipation ability of the structure.The residual deformation of the hysteresis curve is small,the structure has no downward trend,and the energy consumption of the structure is superior.This article has 72 figures,7 tables,and 109 references.