In 180 1, Cognett published a paper on architectural principles, pointing out that the tensile performance of concrete is poor. By 1850, a small cement ship was built for the first time in Lambotte, France, and was exhibited at the Paris Expo in 1855.
Then monier, a French gardener, made a concrete flowerpot reinforced with a metal skeleton at 1867 and obtained a patent. Later, Connor published the first theory and design manuscript about concrete structure in 1886.
1872 The first reinforced concrete building was built in Ward, USA. 1906 Turner developed the first flat plate without beam. Since then, reinforced concrete small components have entered the practical stage of engineering.
2. For the wide application of reinforced concrete structures and prestressed concrete structures, the design and calculation are based on the method of material failure stage.
1922, an Englishman Edison proposed a method for calculating flexural members according to failure stages. 1928 French engineer Frey Sinai invented prestressed concrete.
Since then, the technology and scientific research of reinforced concrete and prestressed concrete have developed rapidly in analysis, design and construction, and many unique buildings have emerged, such as Kresge Hall in Boston, 195 1 Festival Dome in Britain, Marina skyscraper in Chicago, and lakeside building.
1950, the Soviet union formulated the calculation rules of plastic internal force redistribution according to the limit equilibrium theory. 1955 promulgated the limit state design method, thus ending the design calculation method according to the failure stage.
3. The industrial production of components and buildings has expanded the application scope of structural systems, and the design and calculation are based on the limit state method.
Because many big cities are in a state of great waste after World War II, the task of reconstruction is heavy. Precast members and mechanized construction are widely used in the project to speed up the construction. After the Soviet Union put forward the limit state design method, Britain, the Federal Republic of Germany, Canada and Poland adopted this method in 1970.
At the 6th International Conference of European Concrete Committee and International Prestressed Concrete Association (CEB-FIP), suggestions on the design and construction of concrete structures were put forward, which formed an international unified criterion for design ideas.
4. With the formation of a new branch of modern reinforced concrete mechanics, the structural reliability theory based on statistical teaching has gradually entered the practical stage of engineering.
The rapid development of computers makes it possible to perform complex mathematical operations. The design calculation is base on that probability limit state design method. In summary, the calculation theory tends to be perfect, the material strength is constantly improved, the degree of construction mechanization is getting higher and higher, and the building is developing towards long-span and high-rise buildings.
Extended data:
Development status of reinforced concrete;
At present, reinforced concrete is the most widely used structural form in China, accounting for the vast majority of the total, and it is also the most widely used area of reinforced concrete structures in the world.
According to the relevant data of the National Development and Reform Commission, the output of cement, the main raw material in this area, reached1.60 billion tons in 2005, accounting for about 48% of the world's total output. Steel bar and concrete are two completely different building materials, with a large proportion of steel bar, which can bear not only pressure but also tension. However, it has high cost and poor heat insulation performance.
The specific gravity of concrete is relatively small, and it can bear pressure, but it can't bear tension; Its price is cheaper, but it is not strong. The birth of reinforced concrete solved their defects and retained their original advantages, making reinforced concrete the first choice for modern building construction. ?
The history of concrete can be traced back to ancient times. The cementing materials used are clay, lime, gypsum and volcanic ash.
Portland cement began to appear in the 1920s 19. Because of its good strength and durability, easily available raw materials, low cost, especially low energy consumption, it has been widely used.
Development prospect of reinforced concrete;
Reinforced concrete structures are widely used in civil engineering, and all kinds of engineering structures can be built with reinforced concrete.
Reinforced concrete structures have been effectively applied in some special occasions, such as atomic energy engineering, ocean engineering and machinery manufacturing, such as reactor pressure vessels, offshore platforms, giant oil tankers and large-tonnage hydraulic press frames. It solves the technical problems that are difficult to solve in steel structure.
Development Status of Reinforced Concrete Structure in Civil Engineering Network