Construction and maintenance of roads and buildings use up lots of money and resources. Asphalt roads wear out over time, and acquiring concrete for buildings means digging deeper and deeper into quarries for material. But new recycling technologies may take some of the pressure off the world’s resources while keeping roads paved and buildings safe.
Asphalt is a paving material made of gravel and other materials bound together with a thick petroleum. Over time, exposure to the elements causes asphalt to age, become brittle and crack. This means that roads paved with asphalt must be repaved periodically. As the old asphalt is pulled up, only a tiny fraction can be reused: most of it heads to a landfill or gets stacked up for later use.