Aggregate freeze-thaw resistance

It is difficult to find a simple correlation between the freeze-thaw resistance and concrete saturation with water, because there are many factors involved. These factors have an impact on the porosity and they are as follows pores in aggregate grains, paste-aggregate interfacial transition zone, capillary pores ratio in the paste, gel pores, air-voids entrapped during concrete mixture production". However, the microstructure and porosity of cement paste is of principal importance. 

In the concrete mix design relatively little attention is paid to the chemical and mineral composition of aggregate. Obvionsly, grading and physical properties, mainly the compressive strength, abrasion resistance, porosity and freeze-thaw resistance are of the highest importance [287,410]. Only in the case of potential risk of alkali... 

For high freezing and thawing resistance, a very dense structure of material is required with an appropriate system of pores obtained by application of air-entraining admixtures. Also aggregate grains should exhibit adequate frost resistance. 

The resistance to freezing and thawing test provides information about the behaviour of an aggregate subjected to the cyclic action of freezing and thawing. The test is usually conducted in countries having subzero temperatures. 

CEN EN 1367-1.2007. Tests for thermal and weathering properties of aggregates — Part 1 Determination of resistance to freezing and thawing. Brussels CEN. 

Minimises old slab disposal problem Contributes to conservation of natural resources for aggregate production Resistance to freeze and thaw is increased, in some cases... 

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