What aspects should be paid attention to in the construction technology of colored asphalt pavement?
July 15, 2022
1. Mixing of the mixture
Before mixing, the mixing tank and asphalt conveying pipeline of the mixing station should be cleaned to prevent pollution. The raw materials meet the requirements of the mix design. The heating of various materials must reach the temperature required by the specification, and the metering equipment is well prepared. Strictly control the discharge temperature of the asphalt mixture, and discard it when it exceeds 190 °C, because the excessive temperature will affect the color of the asphalt mixture, especially the color of the pigment, and the mixing temperature should be controlled between 160 °C and 180 °C. The mixing time is 10s longer than that of ordinary asphalt mixture, and the pellets and color should be checked at any time when the material is discharged.
2. Temperature control of colored asphalt mixture

As the colored asphalt is used as a pavement cover, the thickness is generally thin. The thickness of the colored asphalt pavement in this project is 2cm, which requires the asphalt discharge temperature to meet the requirements. At the same time, corresponding measures should be taken at the construction site to ensure the asphalt mixing The loss of material temperature will not affect the rolling effect. Because the thickness of the asphalt structure layer is thin and the temperature loses quickly, if the rolling is not followed up in time, it will be very difficult to re-press, the compaction degree will not meet the requirements, and the flatness will be difficult to control. Therefore, adjusting the rolling progress of the road roller, Roll as soon as possible from the initial temperature to 130°C, keep a distance of 2-3 meters from the paver, and seal the temperature of the mixture to create favorable conditions for later recompression and final pressure.


3. Transportation of mixed materials
Ensure that the asphalt concrete transportation vehicles and the mixing and paving capacity have sufficient capacity. At the beginning of the paving, there are more than one trucks waiting in front of the paver. The asphalt mixture is transported by 18-20t dump trucks. Carry out the disclosure to avoid the abnormal situation during the transportation, which will affect the mixed material. The bottom and both sides of the vehicle should be cleaned before transportation, and the oil-water mixture should be applied to remove the visible residual liquid, and the excess mixed liquid should not be accumulated on the bottom of the carriage. Each vehicle is equipped with a tarpaulin covering the mixture. Cover the entire truck
4. Paving of the mixture
Before paving, clean and rinse the surface of the lower layer, and wash away the contaminated sundries. It is strictly forbidden to brake suddenly when the transport vehicle arrives at the scene to reduce the segregation of coarse and fine materials. The material transporter should stop when it is about 10-30cm away from the paver. During the unloading process, the material transporter should be in neutral gear and pushed forward by the paver. It should not hit the paver to ensure the smoothness of the paving layer. The paver takes the curb as the walking guide line, and the half-width paver is paved and formed at one time between the sidewalk and the curb, and the paving thickness is controlled by a mobile automatic leveling reference device.
Due to the width of non-motorized vehicle lanes and site restrictions, the rear eight-wheeled dump trucks cannot directly enter the non-motorized vehicle lanes for paving. After on-site comparison tests, the latter eight-wheeled dump trucks were used to transport the colored asphalt to the construction site, and then two The Z50 row tire loader dumps the material into the paver hopper for color asphalt paving on the upper layer of the non-motorized vehicle lane.
5. Compound rolling
The colored asphalt to be constructed is located on the non-motorized vehicle lane, and the standard section of the interval is only 2.5m wide. Only one double-wheel vibratory road roller can be used for rapid rolling of the road roller. Before and during the rolling process, two small plate compactors should be used to roll the stone edges on both sides, and finally, the road roller should be used for finishing.
6. Color and luster aesthetics assurance control measures
Colored asphalt is different from black asphalt, especially in the same mixing station that produces black asphalt and needs to produce colored asphalt at the same time, it is necessary to carry out some corresponding modification and debugging of the mixing station. The pollution of the colored asphalt becomes dark, and in severe cases it becomes nearly black asphalt. In order to ensure pure color, we take the following measures to control:
For the original black asphalt pipelines (including oil inlet and oil return pipelines), in order to prevent pollution, special pipelines and asphalt storage tanks with suitable capacity are set up to meet the requirements of use.
Before mixing, the heating of various materials must reach the required temperature, and the measuring equipment is accurate and intact. Strictly control the discharge temperature of the asphalt mixture, and discard it when it exceeds 190 °C, because the excessively high temperature will have a certain impact on the color of the asphalt mixture, especially the color of the pigment.
When mixing, the mixing tank should be cleaned first to prevent the effect of colored asphalt from being affected. Especially after the black asphalt mixture is mixed, the heated coarse aggregate can be used to clean the mixing tank 3-4 times, which can basically be cleaned.