Premature deterioration of concrete under freezing and thawing conditions is often attributable to the aggregate fraction. Past research has shown that the freeze-thaw characteristics of aggregate are related, in a general way, to such properties as: 1) porosity, 2) absorption, and 3) bulk specific gravity. Actually it is the pore system--that is, the size, shape, arrangement and continuity of the pores--that governs the freeze-thaw characteristics. Distress in aggregate particles arises from hydrostatic pressure induced when a portion of its absorbed pore-water is frozen. The degree of distress or damage manifested is dependent upon the amount of permeable porosity, the degree of saturation, the severity of freezing, and the rupture strength of the rock particle and the restraint imposed upon it.

Report Date


Report Number

No. 224

Digital Object Identifier



Prepared for the 16th Annual Highway Geology Symposium, University of Kentucky, March 25-27, 1965.