Factors Influencing Frost Resistance

Frost resistance is determined by the number of freeze-thaw cycles that a particular concrete can withstand before reaching a given level of degradation. In general, the loss of mass or the decrease of dynamic elastic modulus are apphed as indexes of degradation. 

Frost resistance is heavily influenced by the degree of saturation of the pores in general there is a critical value, characteristic for each type of concrete (indicatively when about 80-90% of the total porous volume is water filled), below which the concrete is capable of withstanding a high number of freeze-thaw cycles, while above it only a few cycles might be sufficient to damage it. 

Finally, in order to obtain frost-resistant concrete, aggregates must also be able to withstand this type of attack. 

---

The influence of freezing water in capillary pores is a very complex phenomenon and various processes accompany simple hydraulic pressure of ice on hardened cement paste, but the model proposed by Powers was universally accepted as explaining the destructive influence on concrete elements with acceptable agreement with experimental results. That model is considered as a basis for standardized requirements for the design of structures. Furthermore, there is strong experimental evidence that the distribution of the voids is a key factor governing the frost resistance of concrete. This statement is supported by experience and investigations in several countries where the temperature in winter falls below zero. An example of such... 

---