Study On Seismic Performance Of Fabricated Concrete Columns Under Large Diameter Grouting Sleeve

With the promotion of supply-side structural reform and its implementation.In addition,with the continuous demand of green industrialization,prefabricated buildings have become an important trend in the development of modern architecture in China again because of the fast construction cycle and convenient construction.However,the seismic performance of prefabricated buildings has been controversial for a long time,so it is necessary to study the seismic performance of prefabricated buildings.In this paper,10 groups of grouting sleeve specimens with steel bar diameter of 40 mm are designed and subjected to uniaxial tensile test.The failure modes and mechanical properties of 10 groups of grouting sleeve specimens are analyzed by load-displacement curve,and the results are selected as the connecting specimens for seismic performance analysis of frame column model Taking longitudinal reinforcement ratio and axial compression ratio as variables,and designing an integral cast-in-place column as a control group,the seismic performance was numerically analyzed by using finite element software ABAQUS,and the main results are as follows:1.Taking the length,wall thickness and the number of ribs of the grouting sleeve as variables,the uniaxial tensile test is carried out,and the results show that the bearing capacity of the specimen with a length of 700 mm can be improved slightly;The bearing capacity of members with wall thickness of 10 mm is slightly larger than that of members with wall thickness of 8 mm,which has better constraint on grouting material.In practical engineering,when the bearing capacity of sleeves is the same,sleeves with larger wall thickness should be selected;The specimens with 8 ribs have better bonding force with grouting material,better bearing capacity and more reasonable stress.2.With the increase of axial compression ratio,the area enclosed by hysteretic curves of prefabricated specimen PC-01、PC-02 and integral cast-in-place specimen RC decreases,the slope of the rising section of skeleton curve increases,the ultimate bearing capacity increases,the degree of stiffness degradation increases,the displacement ductility coefficient decreases,and the cumulative hysteretic energy consumption decreases,showing poor deformation ability under horizontal earthquake.3.With the increase of longitudinal reinforcement ratio,the hysteresis loop area of prefabricated specimen decreases.Compared with prefabricated specimen PC-01,the cumulative hysteresis energy consumption of prefabricated specimen PC-02 decreases by about 7.9% under 0.1 axial compression ratio and 9.3% under 0.4 axial compression ratio.The bearing capacity of skeleton curve increases and the slope of descending curve becomes steep.Although the stiffness is larger in the early stage of loading,it attenuates seriously in the later stage,and the ductility deformation capacity and accumulated hysteretic energy consumption decrease.4.The hysteresis loop area of the whole cast-in-place specimen is larger than that of the prefabricated specimen,and the slope of the rising section of skeleton curve basically coincides with that of the prefabricated specimen.With the increase of axial compression ratio,the peak bearing capacity of skeleton curve of the whole cast-in-place specimen increases,and the degree of stiffness degradation and attenuation is slower than that of prefabricated specimen,and the ductility deformation ability is better,and the cumulative hysteretic energy consumption is the largest,which shows that the whole cast-in-place specimen has better seismic performance than prefabricated specimen.