Alluvial stone
As Calc (also: Rheinischer Calc or colloquially pumice ) refers to an artificially generated brick from a mixture of 90 parts of coarse pumice sand and 10 parts of hydraulic lime , was cured after the shaping by air drying for at least six months. This building material is similar to today's common pumice or expanded clay - lightweight concrete blocks . It has only a low load-bearing capacity, but it offers good thermal insulation and, due to its low weight, was used not only for walls and interior wall cladding but also for light vaulted structures. In the past, pumice was also supplied loose and, thanks to box molds, could be used on site to make masonry bricks; slag was often used for this purpose.
supporting documents
- ^ Official Journal of the Royal Government of Coblenz, No. 53, December 11, 1873, Art. 1500