Hot in-place recycling construction steps (part 4)

2023-09-12 10:38:03 ENUO

(10) Quality inspection

The road surface after the regeneration construction should be smooth and dense, without oil spillage, looseness, cracks and obvious segregation, etc. The overlapping joints should be tight, smooth and thermally bonded.

After the construction process is completed, tests such as water seepage, friction coefficient, structural depth, and coring will be conducted. During the construction process, the paving materials were sampled and tested. The test contents included: gradation, asphalt content, stability, and flow value. Conduct inspection and acceptance according to the bidding documents and other specifications.

(11) Quality control of regeneration process

1. The paving temperature during regeneration is generally not lower than 120°C. If the heating temperature is too low, it will be difficult for the regeneration agent to blend with the old asphalt, and the regeneration effect will not be achieved. Moreover, the aggregate is easily broken, which will change the gradation composition of the original road surface and fail to meet the paving requirements. If the heating temperature is too high, the asphalt will age and lose the significance of regeneration. Therefore, the operating speed of the thermal regeneration unit must be uniform and moderate.

2. The regeneration depth should be uniform. The milling depth is sometimes deep and sometimes shallow, which will affect the smoothness of the road surface. In addition, the milling depth should be slightly larger than the thickness of the treatment layer to avoid lamination.

3. The heating width should be 10-20cm wider on each side than the milling width to facilitate construction and ensure the temperature of the longitudinal joints, so that the longitudinal joints are dense and not loose.

4. The workability of recycled asphalt mixture is generally worse than that of new asphalt mixture, and the temperature drops faster than that of new asphalt mixture, so it is more difficult to compact than new asphalt mixture. During rolling, the road roller should follow the paver closely to prevent the material temperature from dropping too quickly. The final pressing temperature should be above 90°C.