(1) The mixture ratio of aggregate should be compared and selected through repeated experiments, and verified according to the requirements of particle gradation and whether it is easy to meet the compaction quality standard. At the same time, the production ratio of various aggregates should be considered to ensure the construction quality and reduce the project cost.

(2) Graded macadam on the surface of base, upper ballast bed and lower fill shall meet the requirements of D 15 < 4D85. When the lower fill can't meet this requirement, the surface of the base should adopt a double-layer structure with different particle gradations, or geosynthetics should be laid on the bottom of the foundation bed (when the lower fill is improved soil, it is not restricted by this regulation).

(3) bed surface graded macadam or graded gravel shall be filled in layers, with the maximum filling compaction thickness of each layer not more than 30cm and the minimum filling compaction thickness not less than 15cm. The specific paving thickness and rolling times should be controlled according to the parameters determined by the process test and approved by the supervision engineer.

(4) Before rolling, the filler at the transverse joints should be dug out and mixed with the newly laid filler evenly, and the water content should be adjusted to avoid longitudinal joints.

5] After paving by paver or grader, the segregation phenomenon of coarse and fine aggregate shall be eliminated manually in time.

[6] Local surface unevenness should be filled in, and the quality of the bed surface after rolling should meet the design requirements.

Around the foundation such as structures, artificial and small machines and tools are used for paving and shaping, and small vibration tamping machines and tools are used for tamping.

After a molding, when the surface is still wet, it should be rolled immediately. If the surface water evaporates a lot, it is obviously dry and loses water, and an appropriate amount of water should be sprayed on the surface before rolling. The road paved by grader shall be quickly rolled by tire roller, and the exposed potential unevenness shall be leveled and shaped by grader.

After the completion of bed surface, measures should be taken to control the traffic of vehicles, and bed surface should be well protected to prevent surface disturbance and damage. It is forbidden to make a U-turn or suddenly brake on a completed or running road section.

For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd