The Principal materials used to create slurry seal are aggregate, asphalt emulsion, and fillers, which are mixed together according to a laboratory’s design mix formula. Water is also added for workability. Asphalt emulsions serve as a binder, holding the crushed aggregate together and adhering the new slurry surfacing to the old surface over which it is being applied.

This is the same process as slurry seal but we load the emulsion with polymer. This creates a matrix allowing the layers to be stacked when a slurry is a single layer treatment. Micros are used in high traffic areas, bridge decks and rut filling.

Slurry seal is applied to an existing pavement surface by means of a spreader box linked to the slurry-mixing unit. Slurry is introduced into the spreader box, which then lays down the slurry coating as the mixer/spreader is driven forward.

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). Type I 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 raveling, 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.

As shown in this chart, slurry seal maintenance dramatically extends pavement life. Although the serviceability of an untreated asphalt pavement is still adequate after several years of use, pavement deterioration has already begun. A slurry seal maintenance program undertaken before significant deterioration has begun is essential to proper pavement management. Preventative maintenance is more cost effective than corrective maintenance.

1: As the most versatile of any pavement surface treatment system, slurry seal is also unique in its ability to deposit a durable bituminous mixture in accordance with the demands of a variably textured surface – filling cracks and voids, sealing weather-tight, and providing colour and texture delineation in a single pass.

2: Low cost. Economical to install, highly cost effective in use. Generally slurry seal is 30-50% of the cost of other treatments.

3: Rapid usability. Easy, swift application of a new overlay makes slurry especially attractive for rehabilitating busy thoroughfares, parking lots and airport runways. The new surface is ready for use just hours after application.

4: Correcting problems. Existing distresses in older pavements – surface cracking, raveling, loss of matrix, increased water and air permeability and slipperiness due to flushing or aggregate polishing – can be corrected through a slurry application.

5: Aesthetic value. With one simple application, existing pavement receives a new wearing surface of uniform black colour and texture. Enhanced appearance means increased property value, marketing potential and buyer acceptance. Thoroughfares, shopping centre parking lots and other public or commercial pavements treated with slurry seal become more attractive and eye appealing.