ABSTRACT
Knowledge within the field of plaster and mortar products has for a long time been characterized by a trial-and-error mentality. This has not in reality produced any basic knowledge concerning the behaviour of these materials.
A project was started in the spring of 1992, in order to broaden the knowledge of these materials. 53 different mixes of mortar were tested. The same mixing recipe was used for all mixes. In order to obtain different air content and air entrainment systems, air entraining agents were added. The mortar mixes were tested for a number of properties, in fresh as well as hardened mortar. Parameters of the air entrainment system were determined by thin section technique and microscopic analysis.
In this paper, only the results concerning frost durability is discussed. The results clearly show relationships between the structure of the air entrainment system and frost durability. The traditional structure parameters (total air content, specific surface and Powers spacing factor) are however, in general, not suitable to predict this relationship. In this paper other parameters will be proposed which give a good correlation between the air entrainment system and frost durability in the hardened mortar.
