Because the flatness and slope of plastic playground are very strict, such as the transverse slope of runway is not more than 1: 100, the longitudinal slope is not more than 1: 1000, the transverse slope of basketball court and tennis court is not more than 1: 1000, and the longitudinal slope is not more than. The flatness of all sports venues should be checked within 3mm with a 3 m aluminum alloy ruler, and the qualified rate is as high as 95%, so the technical difficulty is increased in the foundation construction process.
2. Subgrade earthwork treatment
2. 1 Subgrade earthwork is the first important process of mobile foundation engineering, which usually has a large amount of work and many underground pipelines in the old city, which is more complicated. It is necessary to protect all kinds of pipelines and choose construction machinery reasonably.
2.4 humus soil, domestic garbage soil, silt, frozen soil and saline soil shall not be used as filling soil. When filling mechanically, it shall be filled by layers (the virtual paving thickness is 20-30cm), leveled and rolled by layers.
2.5 The rolling work shall be carried out from the inside to the outside of the runway. Generally, the roller is overlapped once 15-20cm, and rolled for about 5-8 times, until there is no obvious wheel track on the surface and the required compactness is achieved.
3. Construction of lime-soil cushion
3. 1 Pressure stabilization is the beginning of rolling. 8 tons of rolling, heavy wheels must be rolled at a uniform speed from the inside to the outside of the runway, and some defects inside and outside the lime soil can be remedied by compaction.
3.2 After the lime soil is sorted, it will be rolled by a roller with a capacity of 12 tons or more in time, and rolled from the inside to the outside of the runway for 4 ~ 6 times, and it will survive that day.
3.3 Lime soil must maintain a certain humidity within 5 ~ 7 days after rolling, which is conducive to the formation of strength and avoids shrinkage, cracking and looseness.
3.4 The compaction thickness of lime soil layer should be 1o ~ 20cm, and the water content of compaction should be "squeezed by hand, but can be scattered when landing", and the principle of "rather high than low, rather shovel than make up" should be mastered in the leveling process.
3.5 Lime-soil structural layer must be cured in wet state for more than seven days, and more water should be used for curing.
4. Construction of lime, fly ash and gravel mixture base
4. 1 The compaction thickness of lime, fly ash and crushed stone mixture is 20cm at the maximum and 10cm at the minimum. When the mixture thickness is greater than 20cm, it should be laid in layers.
4.2 During initial compaction, use a 6-8 ton roller to stabilize the runway from the inside to the outside once or twice, and then repair it immediately. After leveling, use12 ~15t pavement to compact until there are no obvious wheel tracks.
4.3 When multi-layer paving, in order to make the upper and lower layers combine well, the lower layer should be wetted with water after compaction, and then the upper mixture should be paved.
4.4 After compaction, keep in good health in a wet state, generally sprinkling water for at least 7 days.
4.5 The mixture shall be evenly stirred and the color shall be consistent. The maximum particle size of gravel (crushed stone) should not be greater than 50mm, and the mass of ash greater than 20mm should not exceed 10%. It is forbidden to contain undissolved particles in lime.
4.6 After rolling with 12 ton roller, the depth of wheel track shall not be greater than 5mm, and there shall be no floating material, peeling and looseness.
5. Construction of cement macadam stabilized layer
5. 1 Pay attention to the grading of stone powder. Before the ingredients are accurate (cement, stone powder, water ratio and even mixing), strictly debug the equipment to make the ingredients accurate and even.
5.2 The thickness of the stable layer is 150mm, which shall be paved once and compacted once to ensure its effect. After paving and leveling, it will be compacted with an 8-ton roller. When rolling, follow the principle of "light before heavy, inside before outside, slow before fast".
5.3 After molding, a certain humidity should be maintained to facilitate the formation of strength and avoid shrinkage cracks and loose threshing.
6. Asphalt concrete layer construction
6. 1 Before paving, check the width and height of the screed of the paver and adjust the automatic leveling device. Use the entire road width for paving as much as possible. If the road width is divided, the summer-planting should be close and straight, and the thickness should be controlled by setting sample piles.
6.2 The asphalt heating temperature is 130- 150℃, and the mixing temperature is 120- 140℃.
6.3 The on-site control temperature of the mixture is 120- 130℃, the paving temperature is not lower than 1 10℃, and the rolling temperature is 80- 100℃.
6.4 The loose paving coefficient should be considered when paving, which is generally determined during trial paving, and its value is 1. 15 ~ 1.35.
6.5 Paving is to visually inspect the asphalt oil content of asphalt concrete and check the temperature, thickness and appearance of the mixture.
6.6 Good asphalt concrete pavement quality requires good rolling, and the compaction operation is divided into three processes: initial rolling, secondary rolling and final rolling. The initial pressure and temperature are generally 1 10- 130℃. After rolling, check the flatness and trim it if necessary. When recompressing, use 10- 12t static roller or 10- 12t vibratory roller for 4-6 times until it is stable without obvious wheel tracks, and the recompressing temperature should be controlled at 90-10℃; During final pressing, use a 6-8t vibratory roller for static pressing for 2-4 times, and control the final pressing temperature at 70-90℃.
6.7 When rolling, ensure that the roller of the roller is wet to avoid sticking to the asphalt mixture. However, it is also necessary to prevent excessive spraying to avoid rapid cooling of the mixture surface.
6.8 It is forbidden for the roller to make an emergency turn or turn around, move left and right or suddenly brake on the freshly paved mixture. No machinery or vehicles shall be parked before the new road surface is cooled to normal temperature.
6.9 Inspection of rolling quality. The main inspection items are: compactness, thickness and flatness. This project is inspected according to the Standard for Quality Inspection and Evaluation of Highway Engineering.
6. 10 reasonably control the compaction speed, improve the operation high interest rate, generally control it at 2-4km/h, avoid the disconnection of working procedures, increase the rolling time, and avoid the phenomenon of channel and transverse crack.
6. 1 1 Appearance requires uniform apparent density, and some big defects, such as insufficient thickness, poor flatness, looseness and oil flooding, should be reworked in time.