Tuff owes its origin to volcanic activity in the Eastern Eifel. It is referred to as trass after it has been dried and finely ground to cement. Tuff has been used for thousands of years as a natural building material in solidified and ground form as trass in the manufacture of binders. Its history makes this raw material unique, not only interesting for geologists and volcanologists.


Rhenish Trass

The use of trass is always worthwhile if there are high demands on the cohesion and homogeneity of the fresh mortar and concrete, and uniform visible surfaces need to be achieved.


  • leads to greater elasticity and plasticity and thus reduces the incidence of cracks
  • reduces the tendency to effloresce.
  • improves water impermeability.
  • increases cohesion and reduces the mixture’s tendency to separate.
  • prevents water exudation.
  • facilitates pumpability.
  • actively intervenes in the curing process and enables a strong post-curing. TRASS increases resistance against penetrating water.
  • reduces the heat of hydration during partial replacement of cement.


Pozzolana Cement & Portland Pozzolana Cement

Trass cement is a combination derived from Roman times using modern bonding agents. The proportion of trass in the cement gives the mortar, plaster or concrete good workability, a high degree of flexibility, impermeability, high water holding capacity and resistance.

MEURIN Portland puzzolana cement and pozzolana cement (trass cements) are produced by grinding Portland cement clinkers, trass and sulphate agents together as setting regulators. The cements comply with EN 197 requirements.

Trass cement mortars reduce the risk of efflorescence. In the already clinker-reduced cement, the trass component additionally absorbs Ca (OH)2 and forms a very dense and resistant structure due to this crystal formation. Delivery: Trass cement can be delivered either loose or in 25 kg paper bags (net including packaging).

Trass Blast Furnace Cements

Trass blast furnace cement is the further development of the construction mixture of trass and blast furnace cement that has proven its worth for decades.

Trass blast furnace cement is produced ready for the factory by grinding Portland cement clinker, blast furnace slag and trass together. These main cement constituents comply with the requirements of EN 197-1, Sections 5.2.1 to

MEURIN Portland composite cement and composite cement (trass blast furnace cements) are produced by grinding Portland cement clinker, trass and sulphate agents together as setting regulators. The cements comply with EN 197 requirements.

For the production of concretes according to DIN EN 206-1/ DIN 1045-2, Tables F.3.1/F.3.3

For concrete with:

• low heat of hydration development
• high resistance against chemical damage
• post-curing up to 70%
• high water impermeability (without chemical additives)
• good water holding capacity


Trass Lime Mortar

Trass lime mortar is used preferentially in the processing of natural stones in the context of the monument maintenance.