Slurry Seal Oil Slurry Seal Slurry seal is a cold mixture of fine graded aggregate, asphalt emulsion, mineral fillers, polymer and water applied to a pavement as a surface treatment. Slurry seal is used as both a preventive and corrective maintenance of asphalt pavement but is not intended to increase the structural strength of a pavement section. Our quality control staff works together with our customers to develop mix designs that enable us to provide you with the proper slurry seal oil for every application. The addition of polymers to our standard Slurry Seal oil increases durability and versatility.