Since the founding of new China, China's steel output has been low for a long time, so the use of steel must be restricted. In recent years, although the Ministry of construction has begun to pay attention to building bearing plate, the traditional strength is not easy to change. In terms of building skills training, the education system, facilities and building rules have been backward Construction technology and management knowledge structure can not adapt to the development of construction site.
Steel construction needs a lot of professional supporting materials supply, such as strong panel, bolts and so on. Although these have been produced in our country, the industry is still immature, to some extent, restricting the development of floor slab building.
2. Under the pressure, the hoop force between steel tube and concrete is generated, which makes the concrete work in the stress state of three-dimensional compression, greatly improves the compressive strength of concrete, improves the plasticity, and improves the seismic performance, while the thin steel tube is not easy to buckle under the compression of concrete, improves the local stability of steel tube, and makes the steel strength fully play. According to the experimental research, the strength of CFST is several times higher than that of single steel tube or concrete with the same section.
3. The new code of floor bearing plate reflects the research results over the years, which are also the problems often encountered in the current engineering design, such as the bearing capacity of members and joints of steel tube structure, the addition of strength calculation formula of spatial circular tubular joints, the design calculation method of rectangular or square tube structure, and some structural regulations.
4. For steel and concrete composite beams, the calculation method of negative moment position of continuous composite beams is added, the calculation and structural characteristics of composite beams with profiled floor bearing plates, and the design regulations of some composite beams with shear connection are also added. In the construction requirements, the design and construction requirements of large-span roof structure are added, and the requirements of improving the brittle fracture resistance in cold regions are added. These new regulations are an important aspect of improving the calculation method.