The construction of high-speed rail is a huge project involving many fields, requiring a lot of iron and steel resources. In order to reduce the occupation of cultivated land along the way when building high-speed railways, bridges are often used instead of roads, and it is reinforced concrete that erects the viaducts. The bridge body is made of concrete. Concrete is the supporting skeleton of the building and bears the load of the structure, such as columns, beams, concrete walls, etc., and the sand aggregate is the supporting skeleton of the structural concrete. Therefore, the quality requirements for sand and gravel aggregates are extremely strict in engineering construction. High-speed rail is a century-old project. Standards such as "General Specification for Concrete Structures" have made mandatory provisions for sand and gravel materials for structural concrete, such as sand and gravel. Firmness, mud content, gradation, needle flake content, etc., are used as hardness indicators of sand and gravel aggregates.
Take the needle-like aggregate in aggregate as an example. If the coarse and fine aggregates contain a lot of needle-like aggregates, the needle-like aggregates have a special particle shape, which will lead to an increase in the specific surface area, a decrease in the expansion and slump, and a decrease in the fluidity and workability of the concrete. worse. In addition, the more needle-like content in the aggregate, the greater the tendency of water film to accumulate around the particles, resulting in the failure of the cement slurry and the needle-like aggregate to form a good bond, reducing the tensile, compressive, flexural and resistance of the concrete structure. shear strength and other properties. In all kinds of engineering construction, the needle flake aggregate is strictly controlled.
High-speed rail is a linear project. Generally, there will be a material processing base at certain distances. For example, when building bridges, box girders are used. Box girders are processed from reinforced concrete and are prefabricated parts, generally 32 meters long. The weight is 900 tons, and the 40-meter span is 1000 tons. A large number of sand and gravel aggregate supply bases are distributed around the box girder and other components processing bases, which continuously supply raw materials.
Under the current situation of strictly protecting the ecological environment, the mining of natural sand and other resources is strictly limited, and the annual mining volume is often difficult to meet the needs of social construction. Therefore, the use of machinery and equipment to process and produce machine-made sand and gravel has become the mainstream trend. To produce sand and gravel aggregates that meet the quality requirements, in addition to certain requirements for stone materials, the requirements for processing equipment are still quite high.
In the processing process, the first and foremost is crushing, which is divided into coarse crushing and medium and fine crushing. The feeder sends the stone into the jaw crusher for coarse crushing, and the coarsely crushed material is conveyed to the cone crusher or the impact crusher through the belt conveyor for medium and fine crushing; Then there is the sand making screening. The medium and fine crushed materials are sent to the Sand Making Machine by the belt conveyor for crushing, and the products of different sizes are screened by the vibrating screen.
Jaw crusher, suitable for coarse crushing of various types of larger materials
Granite and other rocks are hard in texture and large in size, so they need to be roughly crushed by jaw crusher, then medium and finely crushed by cone crusher, and then crushed by sand making machine. Finally, they are screened and cleaned to meet the standard of use.
SC single-cylinder hydraulic cone crusher is suitable for medium and fine crushing of hard materials such as pebbles and granite
After the materials are crushed and screened, the sand making machine can be used for sand making operations. The produced machine-made sand can be classified according to particle size and used for the needs of different engineering projects.
In addition to raw materials, machinery and equipment, the production process of machine-made sand also needs to consider the site, equipment installation and maintenance, process design and other aspects. Bellian mining machinery manufacturers have rich experience in these aspects and can tailor a set of best matches for different customers. production plan. Choose Bellian to avoid detours, and everything can be done easily.
