At the EU summit you saw it again: the chancellor doesn’t seem to understand the damage he’s doing in Europe – with his way of making decisions.
comment by
Hubert Wetzel
Concrete must be stable, otherwise bridges or houses will collapse. The building material is therefore – according to the DIN EN 206 standard – divided into compressive strength classes. In order to find out how much pressure a certain concrete mixture can withstand, a test cube is placed in a hydraulic press and loaded – until first fine cracks appear, then increasingly wide cracks and the block finally splinteres.