KURT ZEUS Otto-Graf-Institut, Stuttgart

Concrete block masonry has considerable resistance to shrinkage cracking if it has been built correctly with units of low moisture content. Depending on the process of manufacture and the method and time of storage AAC and LWA concrete blocks may have a moisture content such that, built into walls under restraint, cracks occur. The paper distinguishes between two kinds of crack and provides explanations of their formation and how the risk may be reduced.