Mechanical Performance And Design Method Of Demountable Steel Reinforced Concrete Column With Bolted Flange

With the rapid development of comprehensive national strength of China and the rapid renewal of construction engineering technology,the disadvantages of traditional building structure gradually highlight,such as a large number of construction waste is generated in the new,reconstruction,expansion and demolition links of building,which wastes resources and endangers ecological environment.To fit the green development concept,a kind of demountable steel reinforced concrete(DSRC)column with bolted flange is proposed in this paper.DSRC column can realize the reuse of components by bolted flange,the main studies of this paper are the mechanical performance and design method of DSRC column,The main contents and conclusions of study are as follows:The structure composition designs and mechanical performance analysis of DSRC column are carried out.DSRC column consists of beam-column joint,steel reinforced concrete column and bolted flange connection.The mechanical performance analysis of traditional SRC column and DSRC column are carried out by ABAQUS.The results show that the failure processes of the columns are the same under different loading systems,and the peak load of DSRC column is 6.0% lower than SRC column.The shapes of hysteresis curves are plump,the energy consumption capacity and stiffness retreat is the same basically.In the process of loading,the flange plate and concrete are closely connected,bolts and flange are in elastic stage.The pseudo-static analysis of DSRC columns with different parameters is carried out.The results show that the failure modes of DSRC columns include upper column and connection(bolted-flange),upper and lower column and connection,lower column and connection,lower column failure.The seismic performance of the DSRC column is poor in the first two failure modes,while in the latter two failure modes is good.The failure mode of DSRC column is greatly influenced by the thickness of flange plate and the number of bolts: when the flange is thin and bolts is less,DSRC column will occur upper column connection failure;when the flange is thin but the bolts is more,DSRC column will occur upper and lower column connection failure;when the flange is thick and the bolt are more,DSRC column will occur lower column failure.Under the failure mode of lower column,the damage to bolted flange is low still in the limit value of elasto-plastic story drift,the dismountable performance is good.Under the lower column failure mode,the bearing capacity of DSRC columns with different parameters is analyzed.The results show that the bearing capacity of DSRC column will increase with the increase of reinforcement ratio,steel content,concrete strength and section steel strength,and the stirrup ratio,axial pressure ratio;the thickness and position of flange and the number of bolts have little influence on it.The ultimate displacement will increase with the increase of reinforcement ratio,steel content,section steel strength and column height ratio,with the increase of concrete strength the displacement increases first and then decreases,with the increase of axial compression ratio the displacement decreases;the stirrup ratio and the flange thickness and bolts number have little influence on it.In the process of loading,bolted-flange is in elastic undamaged state,the performance of mechanical and demountable is good.The calculation formulas of bearing capacity and design method of DSRC column are proposed.Based on the analysis results of bearing capacity,the correction factor of the calculation formula of DSRC column bending capacity is proposed,and the formula is established.then the formula of bolted flange bending capacity is proposed,and the calculation formulas of flange thickness and bolts number are also proposed.