Lime in Asphalt

Many roading authorities and state transportation departments have found that incorporating hydrated lime and limestone fillers into hot mix asphalt can add years to the life of a highway. 


Hydrated lime improves several chemical and adhesion properties of bitumen and is a viable alternative to other traditional binders such as fly ash.

According to the National Lime Association, some of the key technical benefits of hydrated lime in asphalt include:

  • Hydrated lime reduces stripping as it reacts with highly polar molecules that would otherwise react to form water soluble soaps that promote stripping.
  • Hydrated lime promotes formation of insoluble salts that no longer attract water. Unlike most mineral fillers, hydrated lime is chemically active rather than inert.  It reacts with the bitumen, removing undesirable components at the same time that its tiny particles disperse throughout the mix, thus making the pavement more resistant to rutting and fatigue cracking.
  • Hydrated lime reduces the rate of oxidation and aging of the pavement. Hydrated lime reduces cracking as lime particles form polar molecules that intercept and deflect cracks. Essentially the polar molecules increase the volume of lime particles and assist to prevent cracks from growing.

Graymont also commonly supplies finely ground limestone filler for asphalt manufacturing applications as a supplement or replacement for bag house dust. Various sizes are available and customers can choose from several ground limestone filler products available.  

Graymont is able to supply hydrated lime and limestone fillers for asphalt manufacturers from a number of Graymont sites across our network of plants. In some cases, we are able to offer storage and logistics solutions for mobile asphalt plants by prior arrangement. 

Contact our sales team to enquire about our products for the asphalt industry.

Did you know?

After processing, products derived from limestone can eventually revert to their original chemical form by reacting with carbon dioxide in the atmosphere or from industrial processes.