Fabrication And Mechanical Properties Of Magnetically Oriented Steel Fiber Reinforced Cement-based Composites Based On 3D Printing

3D printing has many advantages,such as no template in the construction process,saving building materials,flexible design and so on.The research from construction methods to building materials has developed rapidly,and has been more and more widely used in the field of construction.But most of the research is from improving the design of building printers and the matching design of materials.It does not fully take into account the advantages of flexible design and accurate positioning of 3D printing.Therefore,it is necessary to put forward a new theory from a new perspective.So we can better apply 3D printing technology to the construction industry.In this paper,the tensile strength and ductility o f concrete can be significantly improved by adding steel fibers to concrete.At the same time,it can improve the crack resistance of concrete and make it have good deformation ability.By using directional steel fibers,the corresponding mechanical and de formation properties can be further improved and the amount of steel fibers can be reduced.It can reduce the consumption of steel fibers and save the cost of buildings by using layered positioning printing method and printing steel fibers only in the part with greater stress.The research results show that the concrete material with good printing effect is prepared,and the HPMC content range is 0.10%-0.25% and the slump range is 75 mm-85 mm,which can well meet the printing requirements.Through experiment s of different slump,steel fiber content and aspect ratio,it is found that when the steel fiber content is constant,the smaller the slump of the material,the larger the volume viscosity of the corresponding cement slurry,and the stronger the directional magnetic induction strength of the steel fiber is required.In the same cement-based materials,the higher the content of steel fibers,the greater the directional magnetic induction strength of steel fibers.In the same cement-based materials,the smaller the aspect ratio is,the smaller the magnetic induction intensity required for fiber orientation is,and the better the orientation effect is.According to the results of finite element simulation,using the characteristics of 3D printing to accurately locate the material distribution,the layered concrete beams with different thickness and location distribution are printed.Through simulation analysis,the strength requirements of concrete can be met and the displacement can be reduced by 17.16%,which improves the deformability of concrete beams.Because the orientation steel fiber reinforced concrete material is printed only at the position where the stress is greater than the tensile strength of plain concrete,and the plain concrete material without steel fiber is printed in other parts,the consumption of steel fiber is greatly saved and the construction cost is reduced.