欧美xx孕妇 I 黄色动漫在线观看 I 欧美色图88 I 久久成人在线 I 国产又粗又长又大 I 性淫影院 I 久久久久久黄色 I 黄色特级视频 I 最新日韩在线 I 欧美揉bbbbb揉bbbbb I 超碰最新在线 I 毛片黄色片 I 日韩欧美aⅴ综合网站发布 I 久久99精品久久久久久园产越南 I av有声小说 I 日本特级淫片 I av不卡一区二区三区 I 在线a免费 I 成年人午夜 I 国产熟妇一区二区三区四区 I 欧美经典一区二区三区 I 天天操天天插天天射 I 狠狠丁香 I 裸体男女树林做爰 I a男人天堂 I 综合五月 I 日本激情视频 I 精品在线一区二区

The four advantages of determining the development direction of steel structure are introduced as follows:

The advantage of steel output under current national policy

Before the 1980s, China produced a small amount of steel, and the state advocated "less use" of steel. China's iron and steel production is constantly increasing, we should promote the "rational use of steel." In the 1990s, China's steel output ranked first in the world. But because the technology of steelmaking in our country is unceasingly backward, we can't make good steel. For this, the country begins to popularize, support to use steel, established the steel group that USES jointly.

Manual manufacturing costs are low

For large buildings, steel structure is undoubtedly the best choice, and high and low buildings have steel structure and concrete structure of two choices. However, with the new generation of young migrant workers prefer to choose low pay, more decent work concept changes and the state pay attention to the issue of migrant workers wage arrears, there is a phenomenon of migrant workers pay settlement on the same day, the payment of cash, concrete construction labor costs continue to increase. In this case, the steel structure with low technical content and simple operation requires much lower labor cost.

Import embarrassing situation under the strategic reserve

China's iron ore is mostly lean ore, can only import a large number of iron ore from Australia. In order to reduce the pressure on imports, China has gradually implemented the steel reserve strategy, turning steel into a reality. Among them, steel structures are favored for their high recovery rate.

Green advantage of steel structure building materials

Concrete structural materials will become construction waste after 50 years, but steel structures can be recycled for use, plus the weight is more reasonable, seismic performance is good, can be welded, can be closed and other advantages, the development of steel structures is the only way.