1, graded sand office and proportion according to the design requirements. If the design can't be explained in detail, it should be mentioned when attending the blue prints.the design to avoid wrangling in later construction. Graded sand is generally used in foundation treatment, so different design requirements are different, mainly according to the bearing capacity of foundation, the load of superstructure and the importance of buildings. I have done several foundation treatments in graded sand: pure sand cushion, 1: 1 graded sand cushion, gravel: sand = 7: 3, graded gravel cushion, gravel: sand = 3: 7 cushion, and so on. From the point of view of pure theoretical research, if graded sand is used, it is necessary to make the respective gradation of sand and gravel, and then mix the gradation of sand and gravel as required. Under the same conditions, the group with the highest density is the most suitable group. After the completion of the construction in graded sand, a field sampling test was conducted. On the basis of passing the sampling test, the static load test is carried out again. Only after passing the static load test can this process be completed.

2. There are pre-embedded pure sand point method for sampling and equal volume substitution method for sampling directly in graded sand. Then, lay a plastic bag in the dug sampling pit and pour water with a cup until the water is consistent with the pit mouth. When it seems that the water is about to overflow, read the data of the measuring cup, and the sum of the data is the excavated volume. Direct sampling is more realistic, which is what we usually do here.

1, graded sand (graded sand) refers to a mixed material of sand or stone with a certain particle size, which is used for foundation or other purposes. Its proportion varies according to the specific engineering design. If there is no provision in the design, you can refer to the quota.

2. Natural gradation refers to sand and gravel.

3. The artificial gradation is gravel (20mm-40mm): natural sand: water =9. 1 1:4.97:3.

4. Graded macadam cushion should be dense and stable, and its particle size grading range should meet the following table:

Particle size classification table

The above two grayscales are both pad grayscales.

The first rule stipulates that the diameter of all particles should not be greater than 50 mm In order to better meet the compactness, the first rule is recommended! In addition, in order to prevent frost heaving and wet softness, attention should be paid to controlling the content of fine materials and plasticity index less than 0.5 mm When used as the cushion of asphalt pavement in moderate and wet sections, lime should be added to the gradation, and the fine materials can be appropriately increased. The addition of lime accounts for 8%- 12% of the fine material content. The purpose is to increase the strength and stability of the mat.

5. Graded macadam is sometimes called graded macadam cushion as cushion, and its particle size is required to be 5-40 mm, of which the content of 25-40 mm is not less than 50%.

(Source: Baidu Encyclopedia: Graded Sand)