Belgian Specifications for Freeze-Thaw-Resistant Pavement Concrete

The Belgian standard specifications contain a number of clear requirements for the composition of concrete mixtures and the properties of fresh and hardened concrete. It is generally known that water and air content have a substantial impact on the frost susceptibility of a concrete surface – the former in a negative and the latter in a positive way. The water absorption test by immersion is a quite simple and rapid test; the result of which is a good indication for water-accessible pores and hence, to a certain extent, for durability. However, in some circumstances the test does lead to erroneous results. To have a better indication of the durability of concrete, scaling of the surface under freeze-thaw cycles in the presence of de-icing salts is tested. This paper describes the relationship between the different parameters of the concrete, i.e. water content, water absorption, air content and resistance to scaling, in more detail. It also explains the influence of the choice of materials and concrete composition on resistance to scaling. The findings are illustrated by a number of examples of concrete mixtures.