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The Challenges and Triumphs of Cold Patch Asphalt


There is a basic problem with repairing roads during the winter months using cold patch asphalt mix: Most formulations don’t work very long, with the same potholes reappearing in a month or two after the material is applied.

That’s because it’s hard to get small batches of hot temperature asphalt that time of year. To apply a hot asphalt patch, workers need a hotbox truck to deliver it from the plant at the ideal temperature (between 275 and 300 degrees F). On a 15-degree day in Detroit or Minneapolis that’s not likely to be possible: hot mix plants are usually closed for the season. There are cold winter-mix asphalt versions, but most cold patch asphalt treatments provide an inferior repair to potholes. Why is that?


Cold patch asphalt in winter Utility Cut needing an asphalt patch
Cold patch asphalt workability Applying a cold patch asphalt in winter

Not all asphalt is the same

The binder in asphalt, bitumen, has “viscoelastic behavior,” meaning it changes with temperature: it’s liquid when hot, and solid when cooled. So when traditional hot asphalt is applied (in warm weather conditions) it forms to the shape of the pothole in the existing pavement with a little help from tamping it down. When it cools, it sets as a solid fill.

But a newer asphalt technology now enables a single-step pothole repair, even in winter. EZ Street Premium Cold Asphalt is made with a polymer-modified mix that can be laid in cold and still form a permanent bond with the surrounding (solid) pavement. This revolutionizes pothole repairs, particularly in winter, effectively eliminating the costly matter of repairing those same pavement breaks twice.

The extra cost of most cold asphalt mixes

Why twice? With traditional cold mix asphalt, the binder has to be formulated to remain pliable while stored and shipped. That pliability is what makes it possible for pavement repair crews to fill potholes in January, for example, when the pothole problem is usually at its peak. But it also means the cold-formulation binder simply isn’t as strong because it remains loose.

So, with traditional cold mix asphalt, departments of transportation in northern climates have to fix everything twice. They apply cold mix filler just to eliminate road hazards in the colder months, then come back a second time – when spring or summer temperatures allow – to make the permanent repair with hot patch asphalt material.

So why do it twice when a one-visit pothole repair can be permanent? EZ Street Premium Cold Asphalt has made that possible, freeing up transportation workers to tend to other tasks when the warmer weather returns – and giving motorists a solid, smooth road to travel on all year long.