1. Asphalt material problems

After some pavements are used for a period of time, it is found that a large area of surface layer is loose. The main reason is the use of unqualified asphalt. The ductility and penetration of this asphalt do not meet the specification requirements. Therefore, after a period of time, the mixture will lose its bonding force, resulting in looseness.

Sometimes, due to the high temperature of asphalt mixture during mixing, the asphalt is burnt, which makes the asphalt lose its strong adhesion and adhesion, resulting in loose pavement and local falling off.

3. Poor acid-base combination of asphalt mixture

In general, asphalt is acidic, and if the stone used is alkaline, it can achieve a better combination. If acidic aggregate is encountered, the bonding force between them will be reduced, and the pavement will peel off and form pits.

4. The connection between layers is seriously polluted

When the subgrade renovation and asphalt mixture paving are carried out at the same time, or the construction duration between layers is long, the pollution of the lower layer is not effectively treated when the upper layer is paved, so that a thin pollution interlayer is formed between the two layers. In this way, there is a lack of effective bonding force between the lower bearing layer and the upper bearing layer, resulting in the spalling of asphalt pavement and the formation of local cavities.