Prime coat construction

Asphalt pavement of gravel gradation, gradation grass-roots gravel and cement, lime, fly ash, and other inorganic materials combined with the stability of soil aggregates or the semi-rigid must spray primer   asphalt.
Primer asphalt appropriate use of slow-pitch onto the cloth-type emulsified asphalt and can be slow liquid condensate oil asphalt or coal tar pitch. Consistency of primer asphalt should be adopted by the  test to determine. Dense surface of semi-rigid suitable than good permeability through the thin layer of asphalt, and gravel grading, grading gravel aggregates, and other grass-roots level should be more thick coat of asphalt. Asphalt grade should be based on the type of grass-roots level, local weather conditions to determine.
Species and the amount should be based on the type of grass-roots level through the test to determine.
Spraying prime should be a little dry on the surface at the end of construction. When the grass-roots level for a longer time after the completion of the surface and too dry, the grass-roots level should be carried out clean-up, grass-roots level in the surface of a small amount of watering, and as soon as the surface is slightly dry  spraying  the prime coat of asphalt.
Prime coat asphalt of  highway and  first class highway  should be sprayed asphalt distributor, secondary roads are also can be hand-spraying machine. When nozzle used for surface-treatment or penetration of the asphalt road surface can not guarantee uniform, the nozzle should be replaced.
Spraying prime coat asphalt should meet the following requirements:
Before spraying asphalt, the road should be cleaned, curb and artificial structures should be adequate protection to prevent pollution.
Prime coat asphalt should be not flow after distributor, a certain depth of penetration into the grass-roots level, can not form a film on the surface.
In case of wind or rain, there shall be no spraying prime asphalt. Spraying should be uniform according to the amount of designed asphalt, when there is missing, the application of artificial fill sprinkling.
After spraying asphalt, is strictly prohibited vehicles, pedestrians through.
In paving asphalt on the surface, if there are local areas through the extra layer of asphalt did not infiltrate the grass-roots level, should be cleared.
After spraying the asphalt, the amount for spreading advised to immediately (2 ~ 3) m3/1000m2 of coarse sand or stone.
In conjunction with pellet feed on the grass-roots level through spraying asphalt, in a timely manner when not paved on the surface, and the need to open construction vehicles, should also be spreading the amount of coarse sand or stone, such a case, the prime coat Asphalt amount should be increased by 10%. Spreading sand or stone, the application of 6 ~ 8t steel drum roller regulator again. When the passage of vehicles, the speed should be controlled. In paving asphalt surface found in local areas, such as former prime coat of asphalt off, should be repaired; when there is excess floating sand or stone, should be removed.
Sprinkle prime coat asphalt as soon as possible after paving asphalt surface. When emulsified asphalt for prime coat, sprinkle cloth should wait for their full infiltration, evaporation before paving asphalt surface, such period not less than 24h.