The U.S. is entering an “aging bridges” crisis, with 39% of a total of 614,387 bridges across the country being older than their design lifetime, most of which still stand in service only thanks to their high build quality. One in ten though, are already considered structurally deficient and are constantly under evaluation from structural engineers.
The cost to build over sixty thousand new bridges is forbidding, so repairing is the option left in the vast majority of the cases. But repairing costs a lot, and when it doesn’t offer a permanent fix for the problem, it costs even more down the road. Also, repairing parts of the road infrastructure frequently causes traffic congestion, which costs fuel and creates transportation delays, having a real impact on the economy of the country.
Teams of scientists from Lyles School and Purdue University have come up with a solution for this, as they have developed a “smart” type of concrete that can actually heal itself from cracks and small fractures. This material is ideal for use in bridges, highways, pavement, and any civil engineering element that is under continuous and intensive use, and is called to go through freezing and extreme heating cycles without requiring maintenance.
This is done by incorporating a polymer into the concrete material, which absorbs water from the atmosphere and expands to fill any newly-formed cracks. This takes place on the micro-meter scale, essentially preventing the damage from growing larger and becoming more serious.
This tech could be combined with sensors in the concrete itself, which would enable the timely detection of more dangerous cracks getting out of the polymer’s control. This would result in a repair crew fixing the problem before it becomes a liability for passing drivers, enabling the maintenance teams to make way more targeted interventions, so time and money is saved.