What is the main purpose of a chip seal treatment?

The main purpose of a chip seal treatment is to provide a cost-effective surface seal that protects the underlying pavement from moisture intrusion, improves skid resistance, and seals minor cracks. A chip seal consists of a layer of asphalt emulsion or liquid asphalt that is sprayed onto the existing pavement surface, followed by a layer of aggregate chips that are embedded into the asphalt. The asphalt binder seals the pavement surface, preventing water from entering and causing damage to the pavement structure. The aggregate chips provide a new wearing surface that improves skid resistance and enhances safety. Chip seals can also seal minor cracks and surface imperfections, preventing them from worsening and extending the life of the pavement. While chip seals can provide some structural benefit, their primary purpose is to provide a surface seal and improve skid resistance. They are typically used on low- to medium-traffic roads as a preventive maintenance treatment. The selection of appropriate aggregate size and type is crucial for the performance of a chip seal. The aggregate should be hard, durable, and well-graded to provide good skid resistance and resist wear.