Dr-Ing. U MEYER(1), Dr-Ing. M ROßBACH(2) and Dr-Ing. D C SCHERMER(3)
(1) Arbeitsgemeinschaft Mauerziegel e. V., Bonn
(2) Institut für Ziegelforschung, Essen
(3) Technische Universität, Munich

Unreinforced clay unit masonry has proved to be an appropriate building material in low and moderate seismicity regions in Central Europe over the centuries. Increased requirements resulting from the load codes were the starting point of investigations into the load bearing behaviour of masonry walls under in plane shear loads.
One among many other aspects is the optimisation of the product properties of vertically perforated clay units in shear walls. The optimisation process, carried out within the EU?sponsored research project ESECMaSE, comprised of an optimisation of the material composition as well as an optimisation of the perfo­ration pattern.
Prototype units were produced and tested. The assumed relevant material properties were significantly improved, but for the first optimisation step this didn’t result in an improved re­sistance of the shear walls. Further optimisation is necessary and has already been started.