Short‐term test method for durability of AAC

Autoclaved aerated concrete is a building material with a high compressive strength at a low bulk density and an excellent thermal insulation. AAC with a bulk density <400 kg/m³ was investigated for their long‐term stability of masonry in 2002 at the Leipnitz University Hannover. During the outdoor storage of the AAC blocks the material from one German producer developed cracks and losses in compressive strength after 18 months. Subsequently AAC manufactures, organized in the European Autoclaved Aerated Concrete Association (EAACA), started a research program for identification of AAC with insufficient long‐term behavior. In the first step numerous AAC products with bulk densities between 260 kg/m³ and 750 kg/m³ were stored in ambient air, rain‐protected for 18 months. No losses in compressive strength for all examined AAC products were measured. That means that the AAC of this one German producer is not representative of building material AAC. Parallel to the outdoor storage a short‐term method was developed, which has a good correlation to the results of the outdoor storage. In a round robin for the new test method, it was shown that the method is applicable.