Potholes plague roads around the world. These pits are annoying for drivers, but even worse, those that haven’t been well maintained may cause as much as a third of all deaths on highways. So scientists in the Netherlands are investigating materials able to repair themselves, and have zeroed in on asphalt and concrete.
Many roads are laid with asphalt. The material is porous, which is both a blessing and a curse: the pores absorb noise but also lead to cracks and potholes. Materials scientist Erik Schlangen, chair of Experimental MicroMechanics at Delft University of Technology, is working on self-healing asphalt. He mixed steel fibers with asphalt to make the material conductive, and then when a large induction machine is run over the asphalt, heat helps close any cracks. The Verge pointed out since the machine is necessary, the asphalt isn’t entirely self-healing, but it does allow for easier repairs.
Self-healing asphalt is undergoing testing on 12 roads in the Netherlands; one has been open since 2010 and all are in excellent condition. Regular asphalt roads tend to stay in good condition for seven to 10 years, however, so Schlangen said in upcoming years the difference will be clearer. He said self-healing asphalt could be 25 percent more expensive than typical asphalt, but could last twice as long. One estimate put the Netherlands’ savings with the self-healing asphalt roads at 90 million Euros every single year.
And asphalt isn’t the only material with which scientists are innovating. Schlangen’s team is also looking at adding bacteria to concrete to make it self-healing as well. Bacteria produce calcium carbonate to fill in cracks. Schlangen said these bacteria can live for over 200 years in nature, so they’ll last for the lifetime of concrete. They also don’t harm humans. The scientists have applied the material to some structures and are working to improve it.
Via The Verge