This report is based on reviews on frost damage mechanisms, on frost requirements in different countries, on research and field studies related to frost resistance and on frost test methods all related to concrete. Focus has been on their relevance in relation to the conditions in the frost exposure classes XF1 – XF4 according to the European concrete standard EN 206.

However, from 19 years of field exposure it can be seen that road environment with de-icing salt is more aggressive than marine environment although they are both covered by exposure class XF4. It is also shown that there is also a large difference between the frost attack exhibited on concrete permanently exposed to external fresh water and one which has a high degree of humidity, but may occasionally dry, which are both covered by XF3.

The influence of carbonation on the salt-frost resistance is complex. On one hand the frost resistance is increased by a lower absorptivity and on the other hand, severe carbonation may destroy the entrained air system. Binders with low resistance to carbonation will therefore scale more than binders with higher carbonation resistance. The difference in chloride concentration between the surrounding solution and the pore solution is a driving potential for microscopic lens growth and scaling.

The report presents a proposal for material and testing requirements for concrete exposed to different frost environments, which are not identical to the exposure classes XF1-XF4. In addition, measures to increase the applicability of the frost test methods, and their reproducibility are proposed.