What does "12 stone" mean?

"12 gravel" represents a gravel particle size range, representing 10-20mm gravel.

The specifications of stone particle size are divided into: 2-4 grades; 4-6, here refers to the length of English.

2-4 is commonly known as 24 points. 1/4- 1/2 inches; 6.35- 12.7mm； The current specification is:10-15 mm.

4-6 is commonly known as: four or six points. 1/2-3/4 inches; 12.7-19.05mm; The current specification is: 15-20mm.

Gravel grading can solve the problems of high dust content, high content of needle-like particles, weak particles and weathered particles, uneven grading, unstable specifications, poor consistency of particle composition and great changes to some extent.

Gradation is the distribution of aggregate particles at all levels, which can be determined by screening test.

Extended data:

Gravel classification refers to the classification of gravel into different grades according to certain methods to meet the needs of engineering.

Gravel grading can solve the problems of high dust content, high content of needle-like particles, weak particles and weathered particles, uneven grading, unstable specifications, poor consistency of particle composition and great changes to some extent.

Most gravel yards in China mainly produce building materials and cement concrete materials, and the produced gravel generally lacks good gradation, which is difficult to meet the needs of highway construction.

Material specifications have a great influence. In pavement construction, gravel raw materials with poor specifications and much dust will segregate asphalt mixture particles.

When local coarse aggregate is too much and fine aggregate is too little, the pavement is not easy to compact. The adhesion between mineral aggregate and asphalt is small, the shear strength is reduced, and the pavement is prone to diseases such as looseness; When there are too many local fine aggregates and too few coarse aggregates, the thermal stability is poor, and the pavement is prone to rutting and locking.

Improving the quality of highway, especially asphalt concrete pavement, mainly depends on the quality of raw materials, and the most important thing is the quality of gravel.

Therefore, it is very necessary to classify the broken stones. Gravel grading is to divide the gravel into different grades according to the particle size of the gravel, that is, gravel grading, or to divide the gravel produced by the stone factory into different grades according to the quality. Generally, crushed stone is graded by graded water washing crushed stone equipment.

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