Slurry (Type I, II, III)
What is Slurry Seal?
Slurry Seal is a mixture of an asphalt emulsion binder, curing agents, and aggregate rock. A specially equipped truck carries various quantities of these unmixed materials which are then blended and spread in a continuous flow. It is then applied with a speader box capable of covering the width of a traffic lane in a single pass. Once applied, Slurry Seal forms a new oil-stone matrix wear surface over the old asphalt.
Types of Slurry
Emulsions of varying composition and setting times are mixed with any one of three grades of aggregates to create slurry seal mixes for specific purposes.
Aggregate types are I (fine), II (general), and III (coarse). Fine aggregate mixtures are used for maximum crack penetration and sealing in low-density/low-wear traffic areas. Type II aggregates are the most commonly used and are widely employed where moderate-to-heavy traffic is found. They seal, correct moderate-to-severe ravelling, oxidation and loss of matrix, and improve skid resistance. Type III corrects severe surface conditions — preventing hydroplaning and providing skid resistance under very heavy traffic loads.
Why use Slurry Seal?
- Used over newly laid pavements, slurry seal will prevent surface distresses such as the effects of weathering from occurring.
- Existing distresses in older pavements — surface cracking, ravelling, loss of matrix, increased water and air permeability, and slipperiness due to flushing and aggregate polishing — can be corrected through a slurry application.
- With one simple application, existing pavement receives a new wearing surface of uniform black color and texture. Thoroughfares, shopping center parking lots, and other public or commercial pavements treated with slurry seal become more attractive and eye-appealing.