The reinforcing bar net is made of longitudinal and transverse reinforcing bars crossed by binding or welding. It is one of the contents of the Ministry of Construction's "Promotion and Application of 10 New Technologies in Construction Industry in 2005".
The theoretical formula for calculating the weight of steel mesh is as follows:
The theoretical weight of steel mesh (KG) = the length (M) * wire diameter (MM) * wire diameter (MM) * 0.00617 (0.616539kg/m) of steel reinforcement used in steel mesh
Reinforcement mesh is used in beam-column floor, roof, wall, concrete pavement, bridge deck pavement, Airport runway, tunnel lining, box culvert, wharf floor, prefabricated components and other fields of industrial and civil buildings.
Prospects for development
The application of welded steel mesh in China is still in its infancy. At present, the proportion of welded steel mesh used in China is less than one tenth of the total amount of steel. In the early 1990s, the welded steel mesh was listed as a key popularization project by the State Science and Technology Commission and the Ministry of Construction, and the national standards and regulations were formulated. With the rapid development of infrastructure in China, the state's investment in infrastructure has continued to grow, and the strategy of developing the western region has been implemented. As the national economic construction enters a new stage, the demand for welded steel bars in energy, transportation, water conservancy, housing and municipal engineering will doubled. Its market application prospect is very broad; steel welding net is suitable for industrialization and large-scale production. It is a new industry with high efficiency, meets the requirements of environmental protection and adapts to the development trend of industrialization of construction industry.
1. Welded net road is the trend of steel industry development in the world.
2. Reinforcement net, a new type of reinforcement, is especially suitable for large-area concrete projects.
3. The wide and rapid popularization and application of cold-drawn ribbed steel bar and hot-rolled three-grade steel bar in China provide a good material basis for the development of welding net. The formal implementation of welding net product standards and usage regulations has played a positive role in improving product quality and accelerating popularization and application.
4. The market of our country has great demand potential for steel mesh.
5. Rebar net is lovely in aesthetics.
6. China is a big steel country in the world.
7. The development of steel mesh in China has already possessed soft and hard conditions.
welding technique
Special GWC welding machine is used for welding. The welding procedure is automatically controlled by computer. The welding mesh hole is uniform, the welding quality is good, and the mechanical properties of steel bars before and after welding are almost unchanged.
The steel mesh should be made of CRB550 grade cold-rolled ribbed steel bar or HRB400 grade hot-rolled ribbed steel bar, or CPB550 grade cold-drawn smooth steel bar.
type
Steel mesh can be divided into cold-rolled ribbed steel mesh, cold-drawn round steel mesh and hot-rolled ribbed steel mesh according to raw materials, among which cold-rolled ribbed steel mesh is the most widely used. Reinforcement mesh can be divided into two types according to the brand, diameter, length and spacing of reinforcing bars: shaped reinforcing bars mesh and customized reinforcing bars mesh.
Reinforcement mesh classification: steel welding mesh, building welding mesh, ribbed welding mesh, coal mine welding mesh, coal mine rolling mesh welding mesh, stainless steel welding mesh, decorative mesh, ribbed reinforcement, stirrups, brick mesh, electric welding mesh, geothermal network, etc.
purpose
1. Application of Reinforcement Mesh in Highway Cement Concrete Pavement Engineering
The minimum diameter and the maximum spacing of the reinforcing steel mesh used for reinforced concrete pavement should conform to the current industry standard "Code for Design of Highway Cement Concrete Pavement" JTG D40. When cold-rolled ribbed bar is used, the diameter of steel bar should not be less than 8 mm, the spacing of longitudinal steel bar should not be more than 200 mm, and the spacing of transverse steel bar should not be more than 300 mm. The longitudinal and transverse reinforcing bars of the welding net should be of the same diameter, and the protective layer thickness of the reinforcing bars should not be less than 50 mm. The welding net for reinforcing the reinforced concrete pavement can be implemented according to the relevant regulations of the welding net for the reinforced concrete pavement.

2. Application of Reinforcement Mesh in Bridge Engineering
Mainly used in municipal bridges and highway bridge deck pavement, old bridge deck reconstruction, pier crack prevention and so on. The quality acceptance of thousands of bridges in China shows that the quality of bridge deck pavement is obviously improved by using welding net. The qualified rate of protective layer thickness is over 97%, the smoothness of bridge deck is improved, there are almost no cracks on bridge deck, the paving speed is increased by more than 50%, and the cost of bridge deck paving is reduced by about 10%. Welded or pre-cooled ribbed steel mesh should be used in the steel mesh of bridge deck pavement, and tied steel mesh should not be used. The diameter and spacing of steel mesh used in bridge deck pavement should be determined according to bridge structure form and load grade. The spacing of reinforcing bars can be 100-200 mm, and the diameter of reinforcing bars should be 6-100 mm. The longitudinal and transverse spacing of the reinforcing steel mesh should be equal, and the thickness of the protective layer on the top of the welding mesh should not be less than 20 mm.
3. Application of Reinforcement Mesh in Tunnel Lining
According to the national standard "Highway Tunnel Design Code" JTGD70-2004.
Ribbed reinforcing bar net should be installed in shotcrete, which can improve the shear and flexural strength of shotcrete, the punching and shearing resistance and flexural resistance of concrete, improve the integrity of shotcrete, reduce the shrinkage cracks of shotcrete and prevent local block falling. The steel mesh should be arranged in rectangular shape, and the steel spacing of the steel mesh should be 150-300 mm. It can adopt the combination mode of 150 mm x 150 mm, 200 mm x 200 mm, 200 mm x 250 mm, 250 mm x 300 mm and 300 mm x 300 mm. The lap length of reinforcing bar net should not be less than 30 days (d is the diameter of reinforcing bar).
The thickness of shotcrete protective layer of steel mesh should not be less than 20 mm. When double-layer steel mesh is used, the distance between two-layer steel mesh should not be less than 60 mm.