Coating concrete with residual ash from burning coal can make it strong enough to withstand hellish conditions — and save governments millions of dollars. Fly ash is an industrial byproduct from coal power plants, which used to be pumped into the atmosphere, but is now collected.
In the USA 130 million tons of it is produced annually, of which 70% ends up in landfills — but it turns out this stuff makes concrete nigh on indestructible.
A coating made from the ash can be used on both the rebar inside the concrete and to repair the material itself, and the modified building material becomes impressively strong. Called Blue Crete Coating, researchers have put the modified concrete through simulated environments of hot, cold and rain far worse than exist on earth, including air pollution 100,000x as acidic as we currently suffer from. The result? The concrete survives more than a year, where the normal stuff crumbles in days.
If this method proves feasible, it could strengthen existing structures, save money for repairs, and deal with the fly ash waste problem — and give us a perfect building material for whenever we colonize the next hell planet.