Research On The Mechanical Properties Of Partially Embedded Steel Recycled Concrete Composite Beam

With the rapid development of construction projects in China,steel-concrete composite structures are widely used in engineering practice with their excellent mechanical properties.Limited by the shortage of construction resources,reducing construction waste,improving the recycling and efficient use of building resources,recycled concrete is gradually used in the project.The full combination of section steel and recycled concrete not only makes use of the stiffness,bearing capacity and seismic performance of section steel,but also gives full play to the performance of recycled concrete.The partially buried box-shaped steel recycled concrete composite beam has many advantages such as low overall instability,large rigidity and high bearing capacity,which can effectively broaden the application scope of recycled concrete in engineering practice,save the height of the building floor,and ensure its overall stability.However,the existing research mainly focuses on the composite structure of section steel and concrete,and lacks the research on the mechanical properties of partially buried box-shaped steel recycled concrete composite beams,which is not conducive to the design calculation of composite beams and the application in actual engineering,so it is urgent to study the mechanical properties of composite beams.Based on this,the mechanical properties of some buried composite beams are studied,and the main research contents and conclusions are as follows:1.A three-dimensional solid finite element analysis model of partially buried box-shaped steel recycled concrete composite beam of sufficient size is established,the effectiveness of the model is verified,and the stress and deformation properties of the composite beam are studied by observing the stress-strain and deformation properties of box-shaped steel and recycled concrete.2.By analyzing the effects of parameter changes such as buried depth,recycled concrete strength,recycled aggregate substitution rate and steel strength on the stress performance of partially buried box-shaped steel recycled concrete composite beams,the results show that improving the strength of recycled concrete and steel strength can improve the bearing capacity of composite beams;The substitution rate of recycled coarse aggregate has little effect on the initial stiffness of the component,and the effect in the elastic stage is almost nothing,but with the increase of the substitution rate,the bearing capacity of the component is gradually reduced.With the increase of burial depth,the cross-sectional height of the composite beam decreases,and the bearing capacity change is not significant,which can better meet the requirements of building floor height.3.The design theory and calculation method of partially buried box-shaped steel recycled concrete composite beam are proposed,and the application scope of partially buried box-shaped steel recycled concrete composite beam engineering is expanded.