Crushing and Grinding

Depending on the type of tests it is sometime necessary to reduce the size of the sample. A jaw crusher, various grinding mills and mortar grinder are available in the lab.

 Schwingmühle Retsch MM 400 für eine Endfeinheit von 5 µm

Figure: Mixer mill MM 400 for dry, wet and cryogenic grinding of small amounts of sample down to a final particle size of 5 µm


Test must be conducted under controlled and reproducible conditions according to the relevant testing standard. A climate room and various climate chambers are available. Additionally several drying chambers are at hand and are often used for determining the dry densities of lightweight concrete samples.

Klimaschrank CTS für die gezielte Probenkonditionierung

Figure: Climate chamber



An autoclave is a gas-tight lockable pressure container which is used for thermal treatment of materials under high pressure. In the case of construction materials autoclaves are used in the production process of autoclaved aerated concrete and sand-lime bricks. Controlling the autoclave process means controlling the curing these construction materials and in that course their strength properties and microstructure. The institute’s autoclave contains up to 11 liters. Its operation temperature ranges from 0 °C to 300 °C at a 24 bar maximum pressure.

Autoklav-Deckel mit Manometer und Ventilen

Figure: Berghoff Highpreactor stainless steel high pressure laboratory reactor


Annealing and Calcining

The annealing furnaces reach 1400 °C maximum operation temperature. They are suitable for controlled calcination of smaller charges of clay and clay mixes. They are also employed for synthesizing cement clinker minerals.

Glühofen mit einer Maximaltemperatur von 1400 °C

Figure: Open annealing furnace