According to the requirements of the IAAF “..... it is very clear that if the International Amateur Athletic Federation rules allow athletes to use studs of a certain length, the surface of the court must have sufficient thickness. Therefore, in certain areas of the court surface, such as javelin The rear part of the throwing area is thicker than the others.....". Because of the different nature of the competition, the size of the thickening zone is not the same, there are 4mx6m, 1.22mx6m, 6mx20m, 3.6mx2m, etc., in addition to the thickness of the thickening to be controlled during construction, the plane size and position of the thickening zone should not Changes, this is the standard for building a field. The thickening zone is generally 5mm. The solution is to reduce the thickness of the asphalt concrete upper layer. See Figure 1.4.17.1. The method for paving the thickened area is to pave the special thickened areas separately after the asphalt concrete has been compacted in the whole field. Small areas such as 6mx1.22m lots, using artificial paving method, large-area sections, can use asphalt concrete paver operation. First measure the payoff line, set the position of the thickening zone, and when paving asphalt concrete, the four sides should be spread 50cm wide to prevent movement during rolling, check the elevation and flatness promptly after paving, and adopt two steel roller compactors. After compaction, it is best to park for 16 hours. At the same time, measure the payout again and mark the location of the thickened area on the asphalt concrete upper layer. Along the inside of the line, a plywood or fiberboard with a width of not less than 30cm is placed with a thickness of 5mm, see Figure 1.4.17.2. 1- Thickened area asphalt concrete; 2 - plywood; 3 - coarse sand; 4 - sand pit direction unit: cm At the same time, a layer of fine sand is thrown in the board, and the thickness is the same as the thickness of the plywood. After the entire upper layer of asphalt concrete has been paved, the fine sand is immediately removed, cleaned, exposing the thickened area, and then rolling. Finally, the plywood is removed and the entire thickening area is completed. Baby Stroller,Travel Stroller,Uppababy Stroller,Lightweight Stroller DongGuan Baby-Plus baby ware Co., Ltd. , https://www.baby-plus.com
