Permacrete

Permacrete is a strong material used in the construction of Cybertronian buildings.

Fiction

IDW Generation 1 comics

The Toraxxis mega-refinery featured walls of permacrete that were too solid for the thieving Dynobots to cut through, so instead they air-dropped Sludge onto the facility, using him as a wrecking ball to simply smash their way inside. Wreckage