Trass lime is a mixture of hydrated lime or marsh lime and ground trass. The term trass is derived from the Dutch tyrass (= putty, glue).
DEVELOPMENT: Trass rock was formed on the earth's crust by volcanic eruptions or meteorite impacts. Together with lime and water, trass lime forms a natural ecological binder.
HISTORY: As early as the 3rd century A.D. the Romans used Rhenish trass, for example for the Cologne-Trier water pipeline, the city walls of Cologne and various buildings in Bonn. Trass lime is also known under the term Roman cement.