The “alkali-silica reaction” causing miles of road construction every summer. The source of a de facto speed limit on the autobahn, this is a materials issue wherein silica (Kieselsäure, lit. “gravel acid”) reacts with cement to form a gel bubble that pushes up to the driving surface, making it as soft as sand. The ingredients in new autobahns are said to be no longer susceptible to this but old ones are crumbling. Much research has been done over the years into ways to slow down Betonkrebs without replacing too much road. Sprays tested have included epoxy resin, boiled linseed oil and/or “hydrophobization,” according to ZDF heute journal reporting on 26 July 2012.
(Oll call ee KEE zell zoy reh ray ock tsee OHN.)