What Is Micro Surfacing

Micro surfacing is a polymer-modified, cold-applied asphalt emulsion treatment used to restore and preserve existing tarmac pavement seals.

It is classified as a preventative maintenance and surface rehabilitation method rather than structural reconstruction.

It is designed to:

Seal surface cracks
Improve skid resistance
Restore surface profile
Prevent water infiltration
Extend pavement life

Composition

Micro surfacing typically consists of:

Polymer-modified emulsion
Crushed aggregate
Mineral filler
Water
Additives to control setting time

The polymer modification improves flexibility, durability, and resistance to deformation under traffic loading.

Application Process

1. Surface Preparation
   Existing pavement is cleaned of debris and loose material. Structural failures such as potholes or base failures must be repaired prior to treatment.
2. Mixing
   The aggregate, emulsion, filler, water, and additives are combined in a specialised mobile mixing unit.
3. Placement
   The mixture is spread evenly across the prepared surface.
   
   

Suitable Conditions

Micro surfacing is appropriate where:

The underlying pavement structure is sound
Surface cracking is present but not structural
Rutting is shallow
Surface oxidation has occurred

It is not intended to correct deep structural failures or base layer instability.

Longevity Comparison

Micro Surfacing
Typical lifespan extension: 5 to 8 years depending on traffic load and climate
Best suited for preventative maintenance cycles

Conventional Asphalt Overlay
Typical lifespan: 10 to 15 years
Higher cost and thicker application
Addresses minor structural deficiencies

Full Reconstruction
Typical lifespan: 20 years or more
Highest cost
Required when base layers have failed

Micro surfacing is most effective when applied before severe deterioration occurs. It significantly delays the need for more expensive rehabilitation interventions.

Performance Benefits

Improved skid resistance
Enhanced waterproofing
Uniform surface texture
Reduced reflective cracking progression
Rapid return to service

Cost Efficiency

When applied within an asset management strategy, micro surfacing reduces lifecycle costs by preserving existing pavement structure and preventing water-related base failures.

Municipalities implementing scheduled micro surfacing programs often achieve improved network condition ratings and more predictable budgeting outcomes.