Revamping Prime Coat Asphalt: How Road Builders Are Adapting to a Changing Regulatory Landscape

May 15, 2024 | Environment, Supply Security

Applying prime coat asphalt in road construction projects is a crucial part of what gives those roads stability and longevity. 

However, concerns have arisen in recent years concerning the emission of volatile organic compounds, or VOCs, into the air during the process. 

This has led to increased interest in alternatives to the cutback asphalt cements historically used in prime coat asphalt applications and the creation of VOC-free alternative road oils. 

Suzanne Kingsbury, Director of Quality

What Does Prime Coat Asphalt Do?

Prime coat asphalt serves multiple purposes. First of all, it serves as a sealant over the first layer of road, keeping dust, debris, and moisture from seeping in and disrupting the stability of the road’s base. 

This is especially important to protect against the elements. Rain can be a road constructor’s worst nightmare, causing massive delays and expenses. But sealants help builders hedge against the elements, eliminating costly rework or road sanding time. 

Secondly, it helps bind the different layers, such as the aggregate base, base course, binder course, and surface course. It prevents slippage and ensures that the road will remain safe, as thousands of cars and trucks drive over it at a wide range of weights, speeds, and weather conditions. 

Environmental Risks of Traditional Prime Coat Asphalt

But traditional methods of applying prime coat asphalt, such as some forms of cutback asphalt, can be dangerous. These methods involve applying a petroleum-based solvent, which “cures” the road as it evaporates, leaving behind the asphalt cement binder. 

In these older methods of road curing, VOCs are released into the air as the petroleum part of the mixture evaporates. VOCs are considered harmful to human health, and to the environment, and initiatives to decrease their emission are gaining ground. 

For example, the Canadian government already began to codify standards to decrease VOC emissions in prime coat asphalt applications in 2016, which they then updated with VOC concentration limits in 2022. 

And U.S. regulators are not far behind. States such as Pennsylvania and Texas have also begun regulating prime coat asphalts to decrease their harmful environmental effects. 

What Makes a Good Prime Coat Asphalt?

With both the importance and risks of prime coat asphalt in mind, these are some of the characteristics of a solution that is both safe and effective: 

  • Adhesion: High tack, a measure of stickiness or adhesion, is important so that the prime coat binds the different layers of asphalt together securely. 
  • Volatility: The prime coat asphalt must not contain dangerous VOCs to protect human and environmental health, and to meet government regulations. 
  • Faster “slow” cure: While slow curing is so-called because it takes longer for the emulsified water to evaporate, this method is gaining popularity because it releases fewer (or even zero) VOCs. When performed with a 60% solids water-based emulsion, which can be diluted 3-to-1 with more water, even the “slow” cure can be relatively quick. 
  • Low viscosity: Prime coat asphalt emulsions spread more easily and seep more into the asphalt than higher viscosity alternatives. 
  • Low-temperature application: Using a prime coat asphalt fit for low temperatures eliminates the need for a heated application and expands the range of weather conditions in which it can be applied to as low as 40º F. 

Renoil Pre-Pave from Renkert Oil is the prime coat asphalt solution that meets all these requirements. 

Without sacrificing the quality, efficacy, or ease of use of our prime coat, we’ve made it completely VOC-free, exceeding the standards set by the Canadian EPA

Renoil Pre-Pave is laying the groundwork for road construction that is environmentally friendly and one step ahead to exceed regulations today and into the future. 

Sourcing Prime Coat Asphalt From Renkert Oil

Renoil Pre-Pave is one of Renkert Oil’s many products remarkable for their safety and efficacy, such as our: 

We deliver these products across the continental United States and to Europe from our strategically located facilities. 

Our rail and truck fleets can deliver smaller quantities by the drum, ISO tank, or Flexitank, and we can also use our partner transportation companies to move bulk orders, including internationally. 

If you’re interested in learning more about using Renoil Pre-Pave, or any of our other specialty oil products, and working with a reliable, established supplier with extensive supply and logistics experience, contact Renkert Oil today.