Slurry sealing originated in Germany and has a history of more than 90 years. Slurry seals have a wide range of applications and can also be used for highway maintenance. Because it has the advantages of saving energy, reducing environmental pollution and extending the construction season, it is increasingly favored by highway technicians and maintenance workers. Slurry sealing layer is made of appropriately graded stone chips or sand, fillers (cement, lime, fly ash, stone powder, etc.), emulsified asphalt, external admixtures and water, which are mixed in a certain proportion to form a slurry and spread A pavement structure that functions as a seal after being paved, hardened, and formed. Because the consistency of this slurry mixture is thin and the shape is like slurry, the paving thickness is generally between 3-10mm, and it mainly plays the role of waterproofing or improving and restoring the pavement function. With the rapid development of polymer-modified emulsified asphalt and the improvement of construction technology, polymer-modified emulsified asphalt slurry seal has appeared.

The slurry seal has the following functions:
1. Waterproofing
      The aggregate particle size of the slurry mixture is relatively fine and has a certain gradation. The emulsified asphalt slurry mixture is formed after the pavement is paved. It can adhere firmly to the road surface to form a dense surface layer, which can prevent rain and snow from penetrating into the base layer and maintain the stability of the base layer and soil base；
2. Anti-slip effect
      Since the paving thickness of the emulsified asphalt slurry mixture is thin, and the coarse materials in its gradation are evenly distributed, and the amount of asphalt is appropriate, the phenomenon of oil flooding on the road will not occur. The road surface has a good rough surface. The friction coefficient is significantly increased, and the anti-skid performance is significantly improved.
3. Wear resistance
      Cationic emulsified asphalt has good adhesion to both acidic and alkaline mineral materials. Therefore, the slurry mixture can be made of high-quality mineral materials that are hard to wear and grind, so it can obtain good wear resistance and extend the service life of the road surface.
4. filling effect
      The emulsified asphalt slurry mixture contains a lot of water, and after mixing, it is in a slurry state and has good fluidity. This slurry has a filling and leveling effect. It can stop small cracks in the road surface and uneven pavement caused by looseness and falling off of the road surface. The slurry can be used to seal cracks and fill shallow pits to improve the smoothness of the road surface.

Advantages of slurry seal:
1. It has better wear resistance, waterproof performance, and stronger adhesion to the underlying layer;
2. It can extend the life of roads and reduce comprehensive maintenance costs;
3. The construction speed is faster and has less impact on traffic;
4. Work at normal temperature, clean and environmentally friendly.

Key technologies for slurry sealing construction:
1. The materials meet the technical requirements. The aggregate is hard, the gradation is reasonable, the emulsifier type is appropriate, and the slurry consistency is moderate.
2. The sealing machine has advanced equipment and stable performance.
3. The old road requires that the overall strength of the old road meets the requirements. The areas with insufficient strength must be reinforced. The pits and serious cracks must be dug and repaired. The bales and washboards must be milled. Cracks larger than 3 mm must be filled in advance. Roads must be cleared.
4. Traffic management. Strictly cut off traffic to prevent vehicles from driving on the slurry seal before it solidifies.