"Due to the characteristics and advantages of steel structure itself, as well as the good industrial foundation of China's steel industry and manufacturing industry, steel structure construction has broad development prospects, and will certainly be a new track for the high-quality development of China's steel industry, related manufacturing industry and construction industry, and a new growth point of local economic development." On November 15, Xia Nong, vice president of the China Iron and Steel Industry Association, pointed out at the "Development of green production of profiles to promote the standardized construction of building steel structures" on-site meeting.

In the context of the development of steel structure construction has become a necessary option to expand the application space of steel materials, Shanxi Iron and Steel Industry Association (hereinafter referred to as Shanxi Steel Association), Shanxi Steel Structure Association, Shanxi Environmental Protection Industry Association hosted the meeting in Quwo, Linfen, Shanxi Province. The meeting was hosted by Shanxi Jinnan Iron and Steel Group Co., LTD. Ministry of Industry and Information Technology Raw material Industry Department Inspector Zhang Haideng, Xia Nong, China Steel Structure Association Executive Vice president Liu Yi, Shanxi Industry and Information Department Deputy Director Li Xin, Linfen City Vice mayor Qiao Feihong, Shanxi Steel Association Executive Vice president Xie Li, Shanxi Steel Structure Association President Li Haiwang, County Party Secretary Wu Bin, Jinnan Iron and Steel Deputy Secretary of the Party Committee, President Zhang Tianfu and leaders of relevant departments, industry experts, financial institutions, representatives of cooperative enterprises and representatives of the news media attended the meeting.

How to build standardized construction? The experts at the meeting put forward: "Design is to build, and construction should be considered when designing." It is necessary to adhere to the design of steel structure buildings with product thinking, and then based on standardized products, the use of digital and intelligent technology to empower the whole industrial chain of steel structure."

"Jinnan steel profile specifications complete categories and sufficient inventory, profiles and galvanized profiles have reached more than 600 specifications, to achieve common specifications from No. 3 Angle steel -600H steel specifications complete, to meet the needs of different customers and pick up at any time." In the future, we will gradually expand the varieties, types and specifications of the production of steel sections to contribute to the standardized construction of steel structures." Zhang Tianfu said.

The development of steel structure is insufficient, and rolled profiles must be applied on a large scale

"The promotion of steel structure is an important area to expand the new demand for steel consumption, and at the same time, steel structure will build a bridge for the coordinated development of green steel and green buildings." Zhang Haidan said at the meeting.

According to the research and calculation data of China Steel Structure Association, in 2023, the steel structure processing volume of the whole industry is about 112 million tons, an increase of 10.89%, which is higher than the crude steel production of most countries; The proportion exceeded 10% for the first time, double that of 10 years ago; There are 11 provinces and cities with steel structure output value exceeding 10 billion yuan, and the total output value of steel structure in 11 provinces and cities accounts for 84.42% of the total output value of steel structure in the country, which has increased year-on-year. The top five provinces in net profit are Zhejiang, Shandong, Anhui, Jiangsu and Hubei, with annual net profit of 9.285 billion yuan, accounting for more than half of the total net profit of all provinces in the country.

"It is worth pointing out that China is a steel structure country, but not a steel structure power." National master of engineering survey and design, chief engineer of China Building Standard Design and Research Institute Yu Yinquan bluntly.

At present, the development of steel structure in China is faced with the homogenization of competition, the increasingly fierce price war, the low degree of industrial chain coordination, the scale of general steel structure parts is difficult to expand, the connection between steel product standards and steel structure building design specifications is not smooth, the talent strength of steel structure design and construction integration is weak, and there is a big gap with developed countries in many aspects.

Take the profile products used in steel structures as an example. Rolled profiles have the advantages of good cross-section performance, low cost, low emission and high manufacturing efficiency, but they have not been well applied in our country. "More than 60% of the steel used in China's steel structure is welded from steel plates, and the hot-rolled steel only accounts for 15% to 20% of the steel used in steel structure, while the hot-rolled steel in developed countries accounts for 40% to 50%, and the application potential of hot-rolled steel is huge." Liu Yi said to Bi.

In recent years, the relevant national policies have mentioned vigorously developing steel structure buildings, and proposed to "increase the application of hot-rolled H-shaped steel, improve the standardization level of components, promote standardized design, and promote the coordinated development of intelligent construction and building industrialization", these are the direction of steel structure industry change, but also to promote the standardization of steel structure construction.

"China urgently needs to develop complete sets of technology to promote the large-scale application of rolled profiles." Yu Yinquan believes that "It should be from the supply of profiles (mainly to solve the coordination problem of profile supply and building use), design technology (mainly to solve the problem of component standardization, node standardization, system standardization and efficient design), construction application (mainly to solve the problem of digitalization and intelligence of steel structure manufacturing and site construction), implementation evaluation (mainly to establish a reasonable quality assurance system and evaluation mechanism)." Four aspects to comprehensively improve the efficiency of the steel structure industry."

Zhang Shen, director of digital technology and director of Engineering digital technology Center, Central South Architectural Design and Research Institute, believes that "steel structure is the direct embodiment of manufacturing industry in the construction industry, should learn manufacturing industry, reduce marginal cost through standardization, productization, scale, and become the pioneer of digital and standardized design."

Without standardized design, there is no standardized construction

So how do you standardize construction? "Without standardized design, there is no standardized construction." Zhang Shen believes that building industrialization must start from the design end, and realize the design for supply chain, and the design for manufacturing and installation (DFMA).

According to reports, the traditional design model is characterized by "wall-throwing design", that is, we design, you manufacture, design does not consider the requirements of manufacturing, and repeatedly modify until the thing is done right. The so-called DFMA, means a deep understanding of the importance of design to quality, manufacturing, assembly into the early design, the first time to get things right. Anything that is not suitable for industrial production is not considered as a design option (except for projects that are not suitable for industrial production). "It is also necessary to break the barriers of separation of design and construction, promote the integration of design, processing, production and construction, and complete the delivery of integrated projects." Zhang Shen stressed.

Construction is based on design, but standardized construction is a systematic project that requires the coordinated development of the whole industrial chain. It is understood that the Steel Association has organized the completion of the "Guidance on vigorously promoting the coordinated development of the whole industry chain of steel structure construction" project research, reported to the relevant ministries and commissions for decision-making reference.

"We should actively create a policy environment conducive to the development of steel structures." Zhang Haideng stressed that highlighting the guidance of standards and improving the standard system of the steel structure construction industry chain. Such as strengthening the connection between steel standards and steel structure building codes, improving the cross-industry steel structure standard system, promoting the standardization and modularization of high-efficiency steel and steel structure parts, and promoting the unification of steel and downstream industry chain standards and specifications. Xia Nong revealed that the Steel Association promotes the integration of building design codes and steel standards, and is working with relevant parties to revise and improve standards such as the National standard for Steel Structure Design, the Technical Standard for prefabricated Steel structure Residential Buildings, and the group standard for prefabricated Steel structure residential major component Dimensions.

Li Haiwang introduced that the Shanxi Steel Association proposed an initial and immature collaborative development model. That is, steel production plants produce steel varieties and specifications that meet the personalized design of steel structures (lightweight), gradually reaching more than 80%, and a reasonable steel warehouse can be established through statistical analysis of the varieties and specifications of existing steel components (far larger than the current steel warehouse); The steel structure processing plant is mainly responsible for the cutting, bending, punching, painting and other processes of the components, and can realize the settlement according to the product delivery; On-site installation units achieve more than 80% assembly installation, and can achieve completion settlement.

"The most fundamental basis of this model is the standardized design of the whole industrial chain." Li Haiwang said that through the standardized design, the design institute directly selects the standardized steel of the steel mill, and the steel structure manufacturer basically does not need to reproduce the welded steel. This will greatly improve production efficiency, save costs, and achieve the purpose of energy saving and carbon reduction and green construction.

Standardized construction is inseparable from large-scale application of rolled profiles, and is inseparable from digital and intelligent enabling. The path of large-scale application of rolled profiles developed by Yu Yinquan's team has many similarities with the model of Shanxi Steel Association, but at the same time, a supplementary measure is proposed: "It is necessary to study the efficient construction and installation technology based on intelligent construction at the construction site, but also to study the detection and certification technology to provide support for the quality of the steel structure, and study the evaluation technology to form a driving mechanism for the application of rolled profiles."

Liu Yi believes that it is necessary to strengthen standardized design, achieve "less specifications, more combinations", increase the specifications of profiles and pipes, and speed up the digitalization process of the whole process of steel structure processing and manufacturing.

Standardized construction will also force the development of green steel

During this on-site meeting, the participating leaders also visited the workshop of Jinnan Profile 4 and the Taizi Lake Heavy Steel Villa project, which are the typical application results of green steel of Jinnan Steel.

"The Prince Lake heavy steel villa model house project used dozens of tons of steel, and it only took two months from breaking ground to moving in." Compared with the traditional brick-concrete structure, the Taizi Lake heavy steel Villa has the advantages of fast construction, high safety factor, good insulation effect, green and environmental protection, and high intelligence." Zhang Tianfu introduced that Jinnan Steel's No. 4 and No. 5 profile workshops are also all built with section steel, and the group also uses green section steel to build photovoltaic bracket intelligent manufacturing projects.

In fact, the standardized construction of steel structures also puts forward requirements for green steel. Facing the needs of the national industry policy, it is urgent to comprehensively improve the efficiency of the steel structure manufacturing and installation process, and reduce the energy consumption and carbon emissions of the whole construction process.

In recent years, Jinnan Iron and Steel has invested heavily in the construction of green steel production line, focusing on the construction of domestic influential profiles and galvanized production base, the main products from the disc screw, wire and other ordinary construction steel, gradually adjusted to I steel, Angle steel, channel steel, H steel, galvanized Angle steel, galvanized channel steel and other green steel products. Strive to build the group into a global small and medium-sized profile category specifications complete, high distribution efficiency, transaction services excellent green profile demonstration benchmarking enterprise.

Why is Jinnan Steel steel called green steel? First, it recyles coke oven gas and converter gas to make glycol and LNG, which meets the requirements of CCUS(Carbon capture, utilization and storage) technology path and realizes zero carbon emissions. Second, fully use new hydrogen energy, reduce the consumption of fossil energy such as fuel oil and LNG, and build a green and low-carbon logistics; The third is to practice the concept of green steel, and gradually replace traditional thermal power generation with photovoltaic and wind power generation to reduce carbon dioxide emissions. "After Jinnan Steel adopts steel-coke combination and steel-coking co-production process, carbon emissions per ton of steel can be reduced to about 1.4 tons, which is better than the advanced level of carbon reduction in the same industry." Zhang Tianfu said.

Yu Yinquan cited the expansion of Xiaojiahe Branch of Peking University Primary School as an example. All the components of this project are made of rolled profiles and derivative products. According to the carbon emission and carbon emission reduction study of the whole process of steel structure manufacturing, the carbon emission of component assembly welding accounts for about 79.77% of the whole process of component manufacturing. The total weld length is 6089.5 meters, and the total weld length of traditional engineering is 9595.1 meters, the total weld length is reduced by 36.5%, and the carbon emission reduction ratio is 0.365x0.7977=0.291, that is, the comprehensive carbon emission is reduced by 29.1%. As proved by the case, the application of rolled profiles in steel structure buildings can greatly reduce carbon emissions.

According to the "Steel Structure Industry" 14th Five-Year Plan and 2035 Vision Goals released by the China Steel Structure Association in October 2021, by 2035, China's steel structure construction application will reach the level of moderately developed countries, and the amount of steel structure will reach more than 200 million tons per year, accounting for more than 25% of crude steel production. The proportion of steel structure buildings in the new construction area has gradually reached about 40%, which basically realizes the intelligent construction of steel structure. Participants believe that to achieve this goal, it is especially necessary to strengthen the scientific and technological innovation capacity of the steel structure industry and promote the coordinated development of the steel structure industry. At the same time, strengthen standardized design, promote the research and development of green products, and actively use digital and intelligent technology to empower the whole industrial chain of steel structures.