Perpetual pavement is a flexible but strong asphalt pavement that doesn't exhibit structural damage even when very high traffic flows over long periods of time. They’re made up of multiple layers of durable asphalt. The bottom layer is designed to be strong but flexible to resist strains that could cause cracks to form from the bottom up. A similar intermediate layer adds additional structural protection, and the final layer, made of rut-resistant hot-mix asphalt (HMA), requires only minimal maintenance. 

These surfaces have been around a long time. Some of the oldest perpetual pavements have been around since before the 1960s. The surfaces created then that were well designed and executed have provided very long usefulness without much maintenance even with heavy traffic. These days, advancements in milling, recycling, and asphalt production technologies make it even more likely that perpetual pavements will perform better and longer.

One interesting part of the asphalt process that you might not be aware of happens before any asphalt is laid. It’s called asphalt milling.

What is asphalt milling?

Milling is the process of removing the top layer of asphalt to a specified and even depth without disturbing the underlying subbase. This allows new asphalt to be laid down without increasing the height of the road and saves you time if the subbase doesn't need to be fixed. Thanks to the milling process curbs, drainage and other existing structures remain undisturbed.