Q: Construction of high-rise steel structure residential buildings: box concrete columns
Box column concrete column is a type of column in which high-strength (C50) grade concrete is poured inside the box column, and a partition is added to support the middle of the box column, forming a mechanism where two materials complement each other and work together. This solves the problem of excessive deformation occurring first before the strength reaches its limit under load. It has the characteristics of high bearing capacity, good seismic performance, and simple construction. Generally, every four floors (each section is about 12 meters long) are used as a production and installation unit, and the entire steel pipe column is lifted in place at once, creating conditions for the installation of the main structure in a flow process. After the box shaped column is wrapped with a fire resistant board, the fire resistance limit of the steel tube concrete column is greater than three hours, meeting the fire protection requirements of high-rise buildings.
The processing of H-beams and the welding of bolts should adopt reasonable processes to minimize residual stresses caused by welding, and use reasonable means to correct errors.
The model of high-strength bolts and the contact surface of high-strength bolts require first grinding with a grinding wheel, with the grinding direction perpendicular to the direction of the component's stress. During installation, remove floating rust with a steel wire brush, and conduct anti slip coefficient tests on the friction surface according to the specifications. The anti slip coefficient is required to not be less than 0.35