Self-healing roads may be the end of potholes
An experiment conducted in the Netherlands may hold the answer to what is annually one of the most expensive maintenance issues each year: potholes.
Each year in the United States, the cost to simply maintain the roads, highways, and bridges is substantial, and it is rising. The current estimate is that it would cost roughly $185 billion per year to maintain the infrastructure, but the average amount spent on maintenance is just $68 billion – and through 2020, that number is going to drop to $46 billion per year. That means at the current pace, shy of a massive infusion, we’re screwed.
Those maintenance costs cover all aspects of repairs for the roads, highways, and bridges, but one of the most common expenses each year is pothole repair.
It’s difficult to put an exact figure on how much it costs to repair potholes annually, given that it changes drastically year to year. Each pothole costs between $23 and $129 each to repair. Times that by several thousand across the country and you begin to get an idea of how expensive potholes can be, and that’s not counting the costs to drivers. Each year it’s estimated that damage from potholes costs $3 billion per year in vehicle repairs.
The idea behind self-healing asphalt is to introduce steel fibers into asphalt, which can then be manipulated to seal together cracks in a road. Asphalt is used for road construction, primarily for its ease of use and its porous nature. It just needs to be heated up to a semi-liquid state, and when it is applied and cool it becomes a durable surface. The Porous nature allows it to absorb noise, but the downside is that it isn’t all that durable. A combination of weather and constant use lead to cracks, and those cracks, in turn, become potholes.
Materials scientist Erik Schlangen from the Delft University had the idea to add steel fibers to the asphalt to create self-healing asphalt. The steel fibers in the asphalt make it electrically conductive. Running an electrical current over the asphalt by way of an enormous magnet heats the fibers, forcing them together. Technically, that means the asphalt isn’t completely self-healing since it requires an external force, but close enough.
Schlangen has been experimenting with the asphalt for seven years now on a dozen roads in the Netherlands. So far the roads remain in ideal condition, but there is a catch – these roads cost 25-percent more than traditional asphalt roads. In theory, the self-healing roads will still be more cost effective considering the maintenance costs, but given the budget shortfalls we face now, coming up with 25-percent more is difficult.
Still, if the costs can be lowered, this might be the future of roads.