Asphalt

Imerys offers multi mineral solutions to the asphalt market. Mineral filler aggregates play an important role in asphalt mixtures because they fill voids and improve the cohesion of asphalt binder.

Asphalt shingles are the most commonly used roofing shingle due to their low cost, ease of installation and fire resistance. Before asphalt can be used in shingle production, it must be softened via an oxidation process where air and catalysts are blown through the hot asphalt mixture. Our ground limestone is pre-heated and added to blown asphalt to improve the final product durability and resistance to fire and weather.    

Calcium carbonate is used in asphalt as a rheology modifier. It also acts as a heat sink and improves the impact resistance and dimensional stability.

Calcium carbonate can be used as back dust which coats the back surface of asphalt shingles to prevent the adhesion before installation

Benefits:

• Extension of higher cost components
• Tensile strength enhancement
• Improves impact resistance
• Dimensional stability

Coarse-grind Imerys talc grades are used as back dust the back-surface of hot asphalt in the production of bitumen membranes, bitumen-based felt and modified bitumen-sheet roofing products.

Imerys talc: 

• Prevent sticking or caking in storage
• Facilitate surface mineralization of the bitumen membrane

Our finer talc grades are also used as fillers in modified bitumen roofing where they: 

• Reduce volatile loss
• Improve UV and weathering properties

Roofing membranes are layered underneath asphalt shingles, their primary purpose is to exclude moisture.

Mica is used for its high aspect ratio, which improves barrier properties. Carbonate is used as a functional filler.

Hot asphalt is mixed with coarse and fine aggregates, then poured over a prepared subgrade and compacted to form a solid paved road.

Carbonate is used in asphalt as a rheology modifier to densify the asphalt and improve its compaction behavior. Mineral fillers are preheated before mixing with asphalt to prevent any changes in viscosity.

Benefits:

• Low moisture content
• Consistent particle size allows for rheology control

Sealcoating, or pavement sealing, is the process of applying a protective coating to asphalt-based pavements to provide a layer of protection from  sunlight (UV rays), water intrusion, tire wear and chemical/petrochemical attack lessen breakdown by freeze / thaw cycle.  It also provides a clean uniform appearance.   

Benefits:

• Superior rheology
• Improved surface texture and color
• Enhanced durability