What are highway bond coats?

Highway bond coats, also known as tack coats, are used to stick an asphalt overlay to an asphalt substrate. The construction of roads generally involves layering different materials on top of each other to create a hardwearing and resilient surface course. However, if the layers are not ‘stuck’ together effectively enough then the surface can ‘slip’ or become damaged.

Bond coats are most used in resurfacing when the asphalt film on the surface has been worn down by traffic. When this happens, aggregate is exposed, and the surface is weaker and more prone to damage. A bond coat replaces the worn away asphalt and promotes bonding to the new overlay.

How are highway bond coats applied?

Highways bond coats are most often applied by a road tank sprayer before the overlay is put down. Once an even coverage of the tack coat has been applied, it usually takes a few moments to cure. Once cured, it is tacky, and the overlay can be laid over it.

Prior to the application of bond coats, surfaces must be sufficiently prepared. Potholes should be repaired, cracks sealed, and the surface cleaned thoroughly to ensure a strong bond is forged between the existing pavement and the new asphalt overlay.

Why are bond coats important?

Highway bond costs are critical to the composition of high performing asphalt surfaces. As each layer in the construction of road surfaces and footpaths is important, the way they are bonded together is equally so. Without the application of an effective tack coat, the surface course will not perform in the way it is designed to.

Without a sufficient bond coat, a surface may begin to disintegrate, especially one which experiences high levels of traffic. Cracking can also occur, as well as delamination and slippage failure.

What are the benefits of bond coats?

Bond coats work as the glue between the layers of asphalt that make up a roadway or pavement. A correctly used tack coat will waterproof the surface and prevent the ingress of water. This serves to protect the surface from the development of potholes and other defects brought about from water penetration.

Bond coats also enhance the durability and resilience of a surface by reducing the risk of slippage between the two courses. This means that surfaces perform well for longer, making bond coats a cost-effective, integral part in the creation of roads and footpaths.

Highway Bondcoats From BituChem

At BituChem, we are highway bond coat specialists. Depending on the type of surface you are creating and the application, we produce a wide range of versatile and effective emulsions. These include:

  • PolyBond – a range of polymer modified bituminous emulsions
  • PolyBond Duo – an innovative 2-in-1 polymer modified bituminous emulsion
  • BituTack 40 & 70 – Traditional cationic emulsions

To learn more about highway bond coats from BituChem, contact us. We have a wide variety of data sheets and information available upon request which we would be happy to share with you.