Towards the golden period of development of steel demand for construction materials was a serious threat
As the main representative of green building, steel structure housing can achieve "good brisk province," that have light weight, construction speed, good performance, energy, materials, water, land, seismic and other excellent performance, is the urban environment One of the smallest impact structures. Therefore, in building the future of urbanization among the steel structure housing will undoubtedly become a mainstream trend.
From the perspective of the process of industrialization, the construction steel industry entered a rapid development period of time is usually about to enter the process of industrialization in the late, when the per capita GDP of about $ 2,000, population urbanization rate reached 50%. At present, China's per capita GDP has been far more than $ 2,000, in 2014 the urbanization rate has reached 54.77%, shows that China's steel industry has had the basis of rapid development.
From the point of view of the product life cycle theory, with the overall cost of steel building structures gradually lower than the case of reinforced concrete structures, steel buildings also have a large-scale promotion conditions.
From the way the cost point of view, all-steel reinforced concrete structures and cost ratio of about 1: 1.33. But the total investment in general, a high-level all-steel, the project investment accounted for only about 50%, which has only 30% of the cost structure of the project cost less. The structure is divided into the upper part of the cost structure and cost base, apparently, eventually told, the cost of steel in total investments are accounted for less than 10% even. 1.33 times the cost difference with reinforced concrete, the ratio of the difference in the total investment will be around 3%.
From the use of the area, the steel due to the light weight, much better than the reinforced concrete structure increased by at least about 5% of the use of the area, such as a building 60-storey, single area of 100 square meters of steel building, if replaced by reinforced concrete, practical Use an area equivalent to a reduction of 3 layers.
From the period, the steel building was significantly less than the reinforced concrete structure. Changsha recently named a "small Amagi," the 57-story building, the main structure by the steel structure, from start to completion, the effective duration of only 12 days, if the use of reinforced concrete structures, may increase more than six months at least. Shorter duration of time in advance not only means that a large number of developers, construction loan, the interest payments of light a day can drive away a Hover H6 of (10 million), can be described as save time is to save money. In summary, plus typical steel building as a green building, as well as the promotion of national key target, the latter is bound to be more rapid development, 2020, total domestic steel construction building scale or by 2013 5% to 15-20%.
Although steel housing in the future will become the main trend of urbanization in the building, but it does not mean in terms of demand for building materials and good.
Construction steel and hot-rolled steel sheet refers, cold-formed or welded sections (I-beam, H-beam, pressure plate, etc.) connected together by connecting pieces (bolts, high strength bolts, etc.) can withstand the load, load transfer architectural form components. On steel demand, accounting for 60% of plate, steel accounted for 21%, steel accounted for 15 percent, while steel and other steel products accounted for only about 4%.
Thus, with the promotion of residential steel building materials demand will inevitably be continued to weaken.
At present, China in housing construction, reinforced concrete structure is accounted for more than 90%. According to the demand structure, the construction industry accounted for about 75 percent of steel construction steel steel consumption. In 2014 construction of apparent consumption of 356 million tons of steel, the annual steel construction industry is about 267 million tons. Reinforced concrete structure that each one percentage point, the demand for building materials is about 2.97 million tons.
If in 2020 the total domestic steel building construction to increase the proportion of 15-20%, it will mean a reduction in the proportion of reinforced concrete structures 10-15 percent, a reduction of about 3000-4500 tons of building materials demand, average annual reduction of 500-750 million tonnes (2015-2020), about 1.4-2.1% in 2014 apparent consumption of building materials.