Classification and use of fine and coarse gravel aggregates
Coarse aggregates generally refer to solid particles with a particle size larger than 4.75mm that play a skeleton role in concrete and have a certain strength.
Fine aggregate, commonly known as “sand”, generally refers to solid particles with a particle size of less than 4.75mm that play a skeleton role in concrete or mortar and have a certain strength. According to different formation conditions, sand can be divided into natural sand and machine-made sand; according to the degree of thickness, sand can be divided into coarse sand, medium sand, and fine sand.
Specifications of stones for preparing concrete
Crushed gravel is an essential material for concrete, and the particle size of the gravel in the aggregate building materials industry is usually between 5mm-40mm.
The particle size of the coarse aggregate used in the first grade is 5~20mm, and the large particle size is 20mm; the second grade is 5~20mm, 20~40mm, and the large particle size is 40mm;
The first grade is a kind of concrete directly mixed with continuously graded stones. The second grade is the concrete mixed with two kinds of continuously graded stones.
Gravel with a 5-10mm particle size is generally used for ground, roof, etc.
Crushed stone with a particle size of 10-20mm is mainly used in surface roads and concrete.
Crushed stone with a particle size of 20-40mm is used in highways, railways, and other fields.