Kapat

SLURRY SEAL / MICRO SURFACING

BITUMEN EMULSION-BASED MORTAR-TYPE PROTECTIVE SURFACINGS

In line with Section 410 of the General Directorate of Highways (KGM) Technical Specifications and the "Bituminous Pavements Preventive Maintenance and Repair Guide" published by KGM R&D Department in December 2024, this is a protective and preventive surfacing method that renews the wearing course using bitumen emulsion-based mortar-type applications on asphalt and Portland cement concrete roads and pavements.

What Is Slurry Seal / Micro Surfacing?

It is a cold asphalt mixture with bitumen emulsion that covers the surface as a very thin mortar layer. It is a cost-effective and efficient rehabilitation and preventive-maintenance method that can be applied to all asphalt roads, state roads, highways, airport runways and taxiways, parking areas, pedestrian paths, and bicycle lanes. It can also be used as a wearing course on stabilized soil roads with recycled asphalt surfacing and over chip seal surfaces (cape seal).

What Is the Difference Between Slurry Seal and Micro Surfacing?

Both are mortar-type bitumen emulsion cold-mix micro-surfacing applications.

Slurry Seal: A mortar-type surfacing method for lower traffic volumes, therefore not requiring polymer-modified bitumen emulsion.

Micro Surfacing: A mortar-type surfacing method applied on roads exposed to heavy traffic, high loads, and severe climatic conditions, using polymer-modified bitumen emulsion.

What Is the Composition of Mortar-Type Surface Coatings?

It is a combination of bitumen emulsion, crushed hard aggregate (basalt/granite), mineral filler (cement/lime), polymer, pigment, chemical additives, and fiber.

How Are Mortar-Type Surface Coatings Applied?

Mortar components are dosed according to the design from truck-mounted storage tanks into the paver mixer, mixed, then discharged onto the spreader box and laid on the road with the appropriate profile and thickness. The application rate per single pass is 4-16 kg/m2.

Depending on traffic and pavement condition, it can be applied in multiple layers and used for wheel-track rut filling. If necessary, a tack coat can be applied on the existing surface.

What Do Mortar-Type Surface Coatings Provide?

• Provides water impermeability.
• Increases skid resistance.
• Improves surface texture and drainage.
• Repairs wheel ruts (Micro Surfacing only).
• Restores deteriorated texture of bituminous surfaces.
• Seals small hairline cracks.
• Fills small potholes.
• Repairs chip seal surfaces with stripping and bleeding problems.
• Covers base layers.
• Can be applied as a wearing course on stabilized base layers.
• Can be applied as a bonding/interlayer course.
• With colored options, can be used on pedestrian paths, bicycle lanes, and shoulders.
• Prepares a suitable surface for road markings.
• Can be used to fill open-graded mixtures.
• Slurry Seal and Micro Surfacing are not used to repair structural failures or large/wide cracks in existing pavements.

What Are the Advantages of Mortar-Type Surface Coatings?

• 35%-45% cost advantage compared to conventional milling and hot-mix resurfacing.
• Operational continuity with quick reopening to traffic in about 60-90 minutes.
• Lane-based/zone-based work in the same direction without requiring traffic diversion.
• On average, about 80% less bitumen and aggregate required than hot-mix asphalt.
• Lower logistics costs and lower machinery fleet investment.
• Potential to extend pavement life by 5-7 years.
• Potential savings in time and fuel due to reduced traffic delays.
• Environmentally friendly cold-mix asphalt with lower carbon emissions.