Stability of aluminium in contact with alkaline building materials

Aluminium and its alloys find application to an increasing extent in building construction. Thus in 1965 about 25% of the total consumption of aluminium in Switzerland was taken up by building construction. The material is employed not only for the frames of windows and display windows, doors, facade claddings, etc., i.e. components of a decorative character, but also on an ever‐increasing scale for shell sections, roof structures, cable conduits and so on, i.e. for functional purposes. The versatile application of aluminium can be attributed to a number of favourable properties, not least among which is its good chemical behaviour. In this article we are especially concerned with the stability of aluminium in contact with alkaline building materials. Direct contact between unprotected aluminium and alkaline building materials, such as cement mortar, is as a rule avoided, since the material is protected on the side of the cement by a coat of lacquer or bitumen. For numerous applications, however, knowledge of the behaviour of the unprotected metal can be of advantage to the planning engineer.