The same asphalt production ductwork in the feature photo (above) after dry ice blast cleaning.

Dry ice blasting, CO2 blasting, and cryogenic cleaning offer the superior solution for removing hardened asphalt from production equipment. Asphalt is a ubiquitous paving material, meaning it’s found everywhere, and its widespread use on roads far surpasses that of concrete. While commonly called “asphalt,” this versatile material comes in many forms, each engineered for a specific purpose. However, when asphalt—or more precisely, hardened bitumen—accumulates in the wrong place, particularly on equipment at industrial facilities producing asphalt, dry ice blasting can effectively remove it.

Bitumen Acts Like Glue Holding Materials Together

At its core, asphalt gets its sticky binding power from bitumen. Think of bitumen as the thick, gooey “leftover” after crude oil has been processed into fuels like gasoline. To make asphalt for roads, this bitumen is heated until it’s liquid and easy to work with. It acts like glue, holding together materials like sand, gravel, and crushed stone. This mixture is then spread onto roadways and compacted, forming the tough pavement we know as asphalt concrete.

Slow Chemical Changes Make It Even Harder and More Durable.

Liquid asphalt hardens primarily as it cools. Bitumen is a thermoplastic material, meaning it softens when hot and hardens as it cools. As the temperature drops, the bitumen binder solidifies, binding the aggregates and creating a stable, durable pavement. Beyond this initial cooling, asphalt also undergoes a longer-term “curing” process. This involves slow chemical changes that continue to make it even harder and more durable.

The Nightmare of Hardened Asphalt Buildup

Asphalt pump and related components in the asphalt supply system

While making asphalt harder and more durable is great for roads, that same toughness makes hardened asphalt a nightmare to remove from equipment and machinery.

Bitumen leaks are a common culprit for this buildup in asphalt manufacturing plants. Hot, liquid bitumen can seep out of places like pumps, valves, and pipe joints. These leaks often happen because seals wear down, vibrations shake things loose, pipes expand and contract with temperature changes, or simply due to poor installation or maintenance.

Traditionally, high-pressure hot water washing might be used to soften and remove bitumen. However, this approach can lead to significant environmental concerns if not managed properly, mainly due to the runoff generated. Bitumen doesn’t dissolve in water. When this contaminated runoff enters storm drains, rivers, lakes, or soaks into the soil, the bitumen and other pollutants can:

• Form surface films: On water bodies, this creates oily films that block oxygen, sunlight, and can harm aquatic life.
• Contaminate sediment: Pollutants can settle at the bottom of water bodies, leading to long-term issues.
• Pollute groundwater: If the runoff soaks into the soil, these contaminants can leach into groundwater, potentially affecting our drinking water.
• Harm ecosystems: Toxic compounds can directly damage aquatic life and disrupt natural soil processes.

What’s more, hot water pressure washing often uses detergents or degreasers. If these aren’t eco-friendly or biodegradable, they add another layer of pollution to the runoff, with harsh chemicals being toxic to plants, animals, and aquatic life.

The Superior Solution: Dry Ice Blasting

The asphalt pump components after dry ice blasting

This is where dry ice blasting offers a much better way to remove hardened asphalt from equipment. It’s a non-destructive cleaning method that leverages two key principles:

Kinetic Energy: Dry ice pellets, which are simply compressed and solidified CO2, are accelerated to high speeds using compressed air. When these pellets impact the hardened asphalt, their kinetic energy helps to break its bond with the surface.

Thermal Shock: Imagine dropping an ice cube into a glass of warm water – the sudden temperature change can cause the ice to crack. Dry ice pellets are extremely cold, around −78.5° C (−109.3° F). When they hit the asphalt, this intense cold causes the asphalt to instantly freeze and become brittle. This rapid cooling leads to thermal shock, making the asphalt crack and shrink, further weakening its adhesion.

As the dry ice pellets impact the surface, they also sublimate – meaning they change directly from a solid to a gas. This gas expands rapidly, further helping to lift and dislodge the cracked asphalt from the equipment surface.

The sublimated CO2 gas simply dissipates

The result? The asphalt loosens and breaks away, making it easy to remove. Best of all, dry ice blasting is non-abrasive and leaves no residue. The sublimated CO2 gas simply dissipates harmlessly into the atmosphere, meaning no messy cleanup of contaminated water or hazardous waste.

Dry ice blasting offers an efficient, effective, and environmentally responsible solution for keeping equipment clean and operational, not only in asphalt manufacturing facilities but across a multitude of industrial settings. Its superiority extends to removing a wide range of materials beyond just asphalt, making it a versatile cleaning method for various industries.

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