ABSTRACT
Abstract Different internal frost damage mechanisms are described briefly. For each mechanism, some of the most relevant applications and consequences are described, together with a discussion of research required for acquiring a deeper knowledge of the mechanism, and its relevance for concrete destruction. The importance of understanding moisture uptake and moisture redistribution processes for clarifying the frost resistance problem is emphasized. Keywords: Concrete, frost resistance, moisture, durability, service life
1 Introduction. Internal frost attack versus surface scaling
There are two main types of frost attack; (i) internal frost attack caused by freezing of moisture inside the material; (ii) surface scaling, normally caused by freezing of weak salt solutions at the surface. Probably, the two types of attack depend on the same basic mechanism, namely that too much moisture is present in the material, either in its interior, or at the surface. The salt-frost attack is, however, normally treated as a separate problem, because it only occurs during unsealed freezing where the concrete stays in contact with a salt solution. Therefore, it is to a very high degree coupled to the manner by which freeze/thaw is performed. Internal frost attack, on the other hand, can take place also when there is no moisture exchange, or moisture contact, between the material and its surroundings. In this paper, only internal frost attack is considered.
2 Destruction mechanisms
