Football ground and sand base construction operation method

The construction process of gravel base includes: paving, rolling, and survival.

The paving of the gravel base is very important. First, the virtual thickness of the paving should be controlled, ie, the compaction coefficient should be mastered. For the use of mechanical paving, such as bulldozers and graders, the paving compaction coefficient can generally be set to 1.20. 1.25, if the artificial paving compaction coefficient can be 1.25~1.30.

After the paving, the place where the coarse aggregate was concentrated first was manually disintegrated and scattered, and the place where the fine sand was concentrated was also dug up and backfilled. After the paving, the entire area can be sprinkled with water. The sprinkler should penetrate the whole structure evenly. After the sprinkler is properly aired for 1~2 h, the surface of the sandstone can be air-dried and then the rolling can be started. The amount of water sprayed on the gravel base can vary according to different seasons. The thickness of the structure is different, see the table below.

Sprinkler scale for gravel substrate

Note: 1. The water content of natural grade sand is about 7%;

2. The optimum water content of natural grade sand is about 5% to 9%.

Grading and roller compaction of grading gravel is best with a larger area, the better, generally 1/3 ~ 1/2 of the football field is better, should not be too small, too scattered. The thickness of the paving shall not exceed 30cm. The beginning of roller compaction shall be carried out from a low position to a high position. The football field shall start rolling from the sideline and gradually proceed to the center of the site. After the initial rolling, the elevation shall be checked and the surface shall be checked. When the flatness is found to be large, timely processing is required. For the more sloppy areas, sand and gravel can be distributed. For higher places, small pits can be dug in intervals, and then sand and gravel around the pit can be spread out and leveled. . For places where the coarse aggregate is concentrated (plum-like), you can dig out the coarse aggregate and replace it with a well-graded sandstone. Do not use the coarse sand fill method. In this way, under the condition of maintaining the optimum moisture content, rolling continues until the requirement for compactness is reached. During the entire rolling process, it is necessary to carefully inspect whether there are “soft bullets” and “frosing” phenomena, and find that one place needs to be thoroughly treated. .

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