Concrete is referred to as concrete for short. It refers to artificial stone made of cement as the main gelling material and proportionally mixed with water, sand and stone. Concrete is one of the raw materials for construction and occupies an important position in the construction industry.As the core material of the building, it helps to fix the building, is the adhesive of the building, and makes the building take shape.After the concrete block is treated by the crusher, it can be turned into stones and sand of different particle sizes. As a recycled aggregate, it can become qualified construction sand and gravel for use in the infrastructure industry, and it is widely used in civil engineering, shipbuilding, machinery industry and other fields.In recent years, the large-scale construction of infrastructure and the advancement of urbanization have made it more and more used. However, what stones are used for concrete?What are the specifications of concrete gravel for construction?Take a look in combination with relevant standards.
Can the broken pebbles be used for concrete?
Concrete is divided into three indicators: C1/C2/C3. The higher the strength, the higher the requirements for sand and gravel. From the table below, the main requirements are hardness, compressive strength, density, etc., and the hardness of the pebbles themselves is not low. As long as they are processed through a reasonable process, they are fully in line with the standards for the preparation of high-strength concrete. In summary, the pebbles can be made into concrete after being broken.
Index requirements for various types of sand and gravel for concrete
The pebbles themselves have good texture, the broken stones have good grain shape, the stones are hard, and they are mixed with other raw materials such as cement to form concrete.After concrete solidifies, its hardness is several times greater than that of ordinary stones, so it has important applications in construction, road laying, and bridge construction.Therefore, the broken cobblestone stones can be used for concrete, and the cobblestone concrete has a better effect.
Moreover, as early as a few years ago, professionals conducted comparative experiments and engineering applications on the physical and mechanical properties of concrete with broken cobblestone configuration. The processed and broken cobblestone set has the dual advantages of cobblestone and artificial gravel, which not only improves the physical indicators of cement concrete, but also improves the characteristics of pumping cement concrete that is easy to shrink and cracks appear, improves the crack resistance, and at the same time achieves good technical, economic and social benefits.
Through comparative experiments and engineering applications on the physical and mechanical properties of concrete configured with broken pebbles, it is found that the use of broken pebbles is not only a rational use of valuable resources, protects the environment, and has the following advantages over artificial gravel：
1. Dredge the waste in the waterway. Broken pebbles are green and environmentally friendly building materials.
2. The cost of concrete is reduced.
3. The dry shrinkage resistance and cracking resistance are significantly improved, which in turn improves the seepage resistance and durability of concrete.
4. Concrete is easy to pump: The frictional resistance of concrete to the mixer, pump, and pump pipe during production and pumping is reduced, it is not easy to block the pipe, easy to pump, and reduces equipment wear and extends the service life of the equipment.、
With the rapid development of the construction industry, the demand for building stones is increasing. However, due to the uneven distribution of rocks and pebbles, natural gravel and pebbles are increasingly scarce in some areas, and the advantages of broken pebbles are becoming more and more prominent.
What are the specifications of concrete gravel for construction?
The stones used for construction are generally divided into two types of stones, gravel and pebbles. Today we will focus on the specifications of concrete gravel for construction.The raw materials used in gravel are generally granite, sandstone, quartzite, basalt, etc. The above types of stones are sharp and non-slip, and the concrete has good adhesion and is stronger and more reliable.Its specifications are roughly divided into 4 types, as follows：
Extra-fine crushed stone: the specification is about 5-10mm.
Fine crushed stone: the specification is about 10-20mm.
Medium gravel: The specification is between 20-40mm.
Coarse gravel: the specification is between 40-150mm.
Extended information: Technical requirements for coarse aggregates for concrete
- Particle grade configuration
When the particle size of the aggregate increases, its specific surface area decreases, and the amount of cement in the concrete is also reduced. Under the condition of meeting the technical requirements, the particle size of the coarse aggregate should be as large as possible; in reinforced concrete projects, the particle size shall not be greater than 1/4 of the smaller cross-section of the concrete structure, and shall not be greater than 3/4 of the smaller net distance of the steel bar.
- Harmful impurities
The mud, silt, fine debris, sulfates, sulfides and organic matter contained in the crude aggregates are all harmful impurities, and their content should comply with the regulations of “Pebbles and Gravel for Construction”. In addition, it is strictly prohibited to mix with calcined dolomite or limestone blocks.
- Needle, flake particles
Too many needle and flake particles in the coarse aggregate will deteriorate the susceptibility and reduce the strength of the concrete. The content of needle and flake particles should be controlled within a certain range.
In recent years, the construction industry has become better and better with the development of society, and it has become more and more standardized. It can be seen from the specifications of concrete gravel for construction alone that the size of gravel used in different places needs to be strictly controlled.Of course, this also puts forward higher requirements for the production and processing of crusher equipment. While ensuring the size of the gravel, the crusher must also pay attention to the quality of the finished product.If you want to know more about the processing of concrete equipment, you can consult the customer service of Liming Heavy Industry for free, and professional technicians will guide you.