From 65438 to 0995, the former Ministry of Construction and the Ministry of Metallurgy began to jointly promote the application of new steel bars. After 10 years of hard work, some achievements have been made. However, due to the uneven level of economic development and the uneven popularization of engineering technology, the application ratio of high-strength steel bars in China is still low, with great regional differences. The eastern region is better than the western region, and big cities are better than small and medium-sized cities.
According to the current standards and codes in China, the amount of high-strength steel bars in concrete structures can theoretically reach 70% of the total amount of steel bars. Non-prestressed steel bars in developed countries are mainly 400MPa, 500MPa or even 600Mpa, and their consumption generally accounts for 70% ~ 80% of the total steel bars. This shows that there is great potential for popularizing and applying high-strength steel bars in China. Considering the actual situation of production, application and research and development in the two major industries, the two departments have carefully studied and determined that by the end of the "Twelfth Five-Year Plan", the use of high-strength steel bars in construction projects should reach at least 65% of the total steel bars, which is a goal that can be achieved through hard work; The technical route of popularization and application is: accelerating the elimination of 335MPa, giving priority to the use of 400MPa, and actively promoting 500MPa threaded steel bars.
The popularization and application of high-strength steel bars involves different industries, different subjects and multiple links, so it is necessary to make overall consideration and coordination, and properly handle the following problems.
Supply and demand problem
Enriching the market supply and meeting the engineering demand is the basis for popularizing the application of high-strength steel bars, giving full play to the basic role of the market in allocating resources, improving the market environment, standardizing the market order, balancing supply and demand and guiding prices through reasonable institutional arrangements. The total demand for steel bars in engineering construction is large, and many specifications are needed. Enterprises hope to supply in time, but individual specifications vary in batch size. Steel bars are produced in batches, and steel enterprises are unwilling to produce them if they fail to reach a certain quantity. At present, the overall product specifications and production capacity of high-strength steel bars can meet the use requirements, but in some areas, it is difficult to buy convenient, reasonable price and complete specifications, not to mention high-strength steel bars. Production and application units should strengthen coordination to solve the contradiction between supply and demand. Encourage production units to innovate supply methods, plan storage, develop or rely on efficient logistics distribution channels to meet market demand in a wider range and in a wider field. Application units should strengthen demand analysis and forecast. The two systems should form an effective connection mechanism, jointly establish an information platform, timely and accurately release the supply and demand and price information of high-strength steel bars, and reasonably guide the supply and consumption.
(B) market mechanism and government guidance
It is necessary to promote the application of high-strength steel bars through the market mechanism, give play to the dominant position and enthusiasm of enterprises, ensure market supply, and adjust the balance between supply and demand. The focus of government work should be shifted to social management and public services. By perfecting the standard system, formulating incentive policies and perfecting supervision measures, the quality of steel bars and projects can be ensured and the price of steel bars can be avoided from fluctuating greatly. The important reason for the success of popularizing high-strength steel bars in Yunnan is to give full play to the enthusiasm of enterprises and the guiding role of the government. Kunming Iron and Steel Group strengthened the research and development of high-strength steel bar technology, actively communicated and coordinated with the construction, design and construction units, held training courses on technical problems in the application of high-strength steel bars, and insured the quality insurance of steel bars with insurance companies. These measures have produced positive results. Relevant departments in Yunnan have strengthened their guidance and issued policies, measures and local standards, such as Guiding Opinions on Promoting HRB500 Hot Rolled Ribbed Steel Bar in Building Engineering, Opinions on Promoting the Application of High Performance Seismic Steel Bar, Technical Measures for the Application of HRB500 Hot Rolled Ribbed Steel Bar in Building Engineering, and Technical Regulations for the Application of 500MPa Hot Rolled Ribbed Steel Bar in Building Engineering, which have promoted the application of high-strength steel bars.
(C) the overall interests and local interests
Production units and application units should have a sense of the overall situation, proceed from the height of overall interests, take into account each other's demands and do a good job together. Due to the harsh external environment and fierce market competition, it is difficult for iron and steel enterprises to operate. Popularizing the application of high-strength steel bars in the construction field has provided new development opportunities for enterprises and expanded the space for transformation and development. Reducing the amount of steel bars to save costs is the main driving force for construction enterprises to use high-strength steel bars. In a certain period of time, the price is still the key factor affecting the application of high-strength steel bars. The overall profit of construction enterprises is meager and it is difficult to bear high material prices; The price should not be too low. Without the enthusiasm of iron and steel enterprises, the supply will be unsustainable. Reasonable price, reasonable profit margin of production units and application units, and "* * *" win-win situation are the premise and important guarantee for the successful application of high-strength steel bars. The experience of Yunnan, Jiangsu, Hebei and other places illustrates this point.
(d) Technological progress and economic applicability
Not all building structures and components should use high-strength steel bars. The higher the strength of steel bars, the better. We should adhere to the principle of saving materials as the core and taking structural safety as the premise, and use it scientifically, reliably, economically and reasonably. There are various forms of building structures, and the design, calculation and structural requirements of different components in the code are also different. The material-saving effect of using high-strength steel bars varies greatly. When the material saving effect is obvious or helps to ensure the quality and safety of buildings, high-strength steel bars should be used, especially for high-rise and long-span buildings; When high strength is not needed, ordinary strength steel bars can be used. All kinds of steel bar production processes can achieve high strength, but the ductility is different and the price is different. It is necessary to comprehensively consider the strength and ductility of steel bars, select steel bars according to the mechanical characteristics of basement walls, foundation slabs and other structures and components, and use steel bars with low ductility and low price to reduce the project cost.
(5) National promotion and key demonstration issues
Based on the comprehensive analysis of the national conditions, the guiding ideology, main objectives and key tasks of the application of high-strength steel bars during the Twelfth Five-Year Plan period are put forward. All localities should set their own goals according to the basic conditions for the application of high-strength steel bars in their own areas: areas with good foundation, such as cities with high application level of 400MPa threaded steel bars, can actively apply 500MPa to strive to achieve national work goals ahead of schedule; Cities with poor foundation should be promoted step by step, with 400MPa as the main application; In areas with seismic fortification requirements, high-strength seismic steel bars should be popularized. The pilot demonstration has played a positive role in the popularization and application of high-strength steel bars throughout the country. The two departments selected Yunnan, Chongqing, Jiangsu, Hebei and Xinjiang as pilot projects, accumulated experience in the production and application of high-strength steel bars through demonstrations of cities, iron and steel enterprises and construction projects in different regions and conditions, and established a coordinated management mechanism for the whole process of promotion and application, such as production, distribution, design, construction, supervision and acceptance.
Third, earnestly complete the task of popularizing and applying high-strength steel bars.
The two departments jointly issued the Guiding Opinions, set up a coordination group and a technical guidance group for the promotion and application of high-strength steel bars, and initially formed a cooperative working mechanism, policy and technical support system. In recent years, many places have accumulated a lot of experience, and there will be exchanges during this meeting. In order to ensure the implementation of popularization and application of high-strength steel bars, we should focus on the following work at present:
(1) Strengthen organizational leadership and coordination. The application of high-strength steel bars involves a wide range and has strong correlation. All localities should attach great importance to it, strengthen leadership, set up leadership and work coordination institutions with the participation of relevant departments in accordance with the requirements of the Guiding Opinions, improve the system, clarify responsibilities, formulate plans, form a joint promotion mechanism, strengthen stage target management, strengthen process supervision, and ensure the implementation of deployment and inspection.
(2) Improve relevant policies and measures. The two departments are working hard to study and promote the incentive policies and measures for the application of high-strength steel bars. First, together with the National Development and Reform Commission, the Ministry of Finance and other departments, iron and steel enterprises will eliminate backward production capacity and produce high-strength steel bars into the scope of technical transformation funds; Incorporate the application of high-strength steel bars into the green building action plan, green building logo evaluation and engineering awards; Financial support policies for saving materials in the field of construction engineering. All localities should also formulate support policies in light of actual conditions. The second is to improve the relevant standards and specifications, further revise the Code for Design of Concrete Structures that has been incorporated into 500MPa steel bars, and start the revision of Technical Specification for Mechanical Connection of Steel Bars and Code for Welding and Acceptance of Steel Bars. And promulgated the national product standard "Steel for Reinforced Concrete".
(3) Do a good demonstration. Pilot areas should be in accordance with the requirements of the "demonstration work plan", strong leadership, do a good job of implementation, and complete the task on time. The demonstration work is carried out at the same time as the national promotion, and we will organize the exchange and promotion of good experiences in the demonstration process; We will also take measures to solve the sexual problems that arise. All regions can also learn from this model, and on the basis of comprehensive promotion, select some cities and projects to demonstrate and play a typical guiding role.
(4) Strengthen technology research and development and guidance. The coordination group will organize research on the production, processing, mechanical connection, welding and other technologies and structural design software of 500MPa and above steel bars, strengthen the research on improving the comprehensive performance of high-strength steel bars and the seismic performance of high-strength steel bars and high-strength concrete structural members, and explore ways to accurately identify the brand of steel bars to avoid confusion. Compile auxiliary technical data such as application atlas, manual and guide of high-strength reinforcement. All localities should set up a technical guidance group for the popularization and application of high-strength steel bars composed of two system experts, establish a consulting platform, smooth communication channels and provide guidance in time.
(5) Intensify publicity and training. The two local departments should organize and coordinate around the social and economic benefits of the application of high-strength steel bars, and use newspapers, magazines, internet and other media to carry out in-depth and powerful publicity through case analysis, expert interviews and experience exchange. According to the relevant standards and norms, technical personnel of engineering design, construction and supervision units shall be trained in the application technology of high-strength steel bars, with special emphasis on remote areas and economically underdeveloped areas and small and medium-sized cities. The coordination group is organizing experts to compile teaching materials and will organize teacher training throughout the country in the near future.
(6) Strengthen supervision and inspection. This year, the two departments will supervise and inspect the implementation of relevant engineering construction standards and steel bar product standards, strictly control the negative deviation of steel bar diameter, and put an end to slimming steel bars. All localities should take the rational use of high-strength steel bars as an important content of construction drawing review and project quality supervision, and strictly control it. Construction, design, construction and supervision units should conscientiously perform their duties, strengthen management and ensure the quality of the project. At the same time, all localities should promptly feedback the new situations and new problems encountered in the popularization and application, and the two departments should pay close attention to research and put forward solutions.