Martin Product Sales LLC
Tack & Prime
“A good application of tack is critical to the long term success of a hot mix asphalt overlay.” – AASHTO Subcommittee on Construction, 2006
Increasing Strength & Fatigue Life
Tack and prime coats are spray applications of asphalt emulsion to prepare pavements for new asphalt. They eliminate slippage planes and provide a bond between the existing pavement and new overlays or patches. Recent research has demonstrated that effective tack coats significantly increase the strength and fatigue life of pavements at a very low cost.
Tack & Prime Benefits
- Low cost treatment significantly increases bond strength between pavement layers
- Stronger bond between layers increases pavement structural strength and fatigue life.
- Asphalt emulsion tack prevents slippage and reduces pushing and shoving.
Surface Preparation & Construction
On existing asphalt or concrete pavements, the surface should be prepared with any necessary repairs and cleaned free of dust, loose or foreign matter or any other material which would hinder the adhesion of the emulsified asphalt. Gravel bases should be graded and compacted.
The application rate should give a uniform coverage of just enough asphalt for a thin, tacky, adhesive film without running off the road’s surface. The emulsions typically are diluted prior to the application to reduce the viscosity for spraying, to allow filling of small cracks or voids and to more accurately apply very small quantities of residual asphalt per square yard.
The emulsion should be sprayed by a properly calibrated pressure distributor at a uniform rate, without splattering or drilling from the spray bar. The nozzle angle and spray bar height should be adjusted to insure that the spray pattern is even and will give the best tack. The emulsion should be allowed to break before the new surface is applied, and traffic should be strictly controlled to prevent damage to the newly applied tack.