Study On Mechanical Properties Of In-situ Printed Reinforced Concrete Wall With Core Column

With the continuous improvement of the global economic development level,people continue to pursue a better life,and their requirements in terms of construction and housing have also increased significantly.New buildings with highly individualized,green and environmentally friendly features have become a new trend in building upgrades and structural transformations.3D printing technology,which integrates advanced technologies such as Internet technology,smart equipment,and automation,has entered the construction industry,and 3D printing of buildings has begun to become a hot topic for industry exploration.Compared with prefabricated building construction,3D printing technology can carry out the original printing and construction process at the construction site,eliminating intermediate links,and complementing the prefabricated construction in terms of standardization and construction efficiency.In order to explore the application possibilities of 3D printing technology in in-situ printing of structural parts,this article focuses on the axial compression performance of in-situ printed core column reinforced concrete walls.The main research contents are as follows:In this paper,12 pieces of in-situ printed core-column reinforced concrete walls are designed and produced,and the basic form of in-situ printed core-column reinforced concrete walls is explained in detail.Influencing factors such as the number of core columns,the shape of the core column hoops,the spacing of the stirrups,the size of the longitudinal reinforcement,and the connection of the horizontal reinforcement are set.Axial compression performance test was carried out on the wall specimens to study the failure form and mechanical performance of the in-situ printed core column wall under the action of axial load.The test results show that the process of wall cracking and failure is similar to the axial compression failure of ordinary steel-concrete walls,which can be divided into three stages:elastic stage,elastoplastic stage,and failure stage;there are three manifestations of wall failure,Respectively,are the collapse of both sides of the wall,the overall damage of the wall,and the partial overall damage of the wall;The existence of core column holes has an impact on the integrity of the wall.The three-core column wall has an additional hole in the middle of the wall,which weakens the integrity of the printed wall,which is manifested in the failure of the walls on both sides.The printing part around the core column is only composed of two 20 mm wide printing strips,which are weak parts,which are the first cracking position during the loading process,and the most severely damaged position after reaching the ultimate load.The load-vertical displacement curve of each specimen basically presents a linear relationship,and will go through an elastic stage,an elastoplastic stage,and a failure stage,which is consistent with the failure characterization of the wall,and the wall has relatively good overall working performance and rigidity;The load-vertical displacement curve of each specimen presents two different forms in the failure stage.One is that the slope of the curve changes less after reaching the ultimate load,the load decreases slowly with the increase of displacement,and the wall remains relatively stable after failure.High bearing capacity;The other is that the slope of the curve changes abruptly after reaching the ultimate load.The concrete exits due to cracks,and the wall’s bearing capacity drops drastically.For printing walls,the addition of transverse steel mesh can make up for the weakening effect of the printing process,restrain the deformation of the wall,and indirectly improve the load-bearing capacity of the wall.The load-strain data of the transverse steel bars show an increasing trend as the load increases,and they are all in tension.The specimen is under the overall force and has good overall performance;the load-strain curve of the vertical steel bars is basically linear,Most of the steel bars reach yield in the failure state,and the steel bars and concrete work together to the later stage of loading,and the steel bars yield first,and the failure state of the specimen appears as brittle failure.After conducting the test phenomenon and data analysis,comprehensively consider the influence of the sample form,the printing concrete technology,the participation of the transverse steel bar,and the wall height-to-thickness ratio.Refer to the calculation method of the bearing capacity of the combined wall of brick masonry and reinforced concrete construction column,A calculation formula for the axial compression bearing capacity of in-situ printed core column reinforced concrete walls is proposed,the test value is compared with the theoretical calculation value,which proves the reliability of the formula.On the basis of experimental research,the in-situ printed core column reinforced concrete wall was numerically simulated based on the ABAQUS finite element analysis software,and the force process and failure mode of the model subjected to axial load under different working conditions were analyzed.And compare the analysis results with experimental phenomena to verify the validity of the numerical model,Based on the validation of the model,the influence of the core column strength on the axial compression performance of the printed core column reinforced concrete wall was further analyzed.