Measuring and lofting-arranging material piles-arranging road grooves-paving macadam-preloading-grouting mud-paving joint materials-rolling.

Thickness requirements and laying methods of mudstone pavement

Mud bound macadam is generally paved in two layers, the upper layer is 6~ 10cm thick and the lower layer is 9~ 14cm thick.

Paving mud and stone

After the road trough is completed, the crushed stone shall be paved according to the loose paving thickness (about 1.2~ 1.3 times of the compacted thickness), with uniform size and particle size distribution, consistent vertical and horizontal sections and thickness. The aggregate size of the main layer is generally 1~2 or 2~3 gravels of the bottom layer and 3~4 gravels of the surface layer.

Compaction of mudstone

Mudstone rolling is divided into two processes: preloading and rolling, in which mud filling and caulking are completed. After the gravel is paved, it will be pre-compacted with a light roller, and the rolling speed will be slow, about 25 ~ 30m per minute, and the wheel tracks will overlap by 25 ~ 30m. Generally, it is rolled 4~5 times until the stone is not loose. Excessive rolling will block cracks in gravel and hinder grouting.

On the pre-pressed gravel layer, cement slurry should be poured evenly and thoroughly, and the surface should be flush with the gravel, but the edges and corners of the gravel should still be exposed above the cement slurry.

After grouting 1~2h, when pouring the slurry, the air in the gap overflows. Before the surface is wet, spread 5~ 15mm sealing material (about1~1.5m3100m2), and the sealing material should be spread evenly.

After spreading the caulking materials, roll them with a medium-sized roller, and pay attention to sweep the stone chips evenly with a broom at any time. If the surface is too dry, it must be watered and crushed slightly. If the surface is too wet, it must be dried before pressing. In the final rolling stage, the soil in the gravel cracks should be turned over to the road surface and bonded with the scattered stone chips into a solid whole.