**9. Conclusions**

This chapter discusses theoretically the freeze/thaw attack of concrete in terms of its mechanism affected factors. Two types of freeze/thaw attack were discussed, Internal frost damage and Surface scaling. Either type of freeze/thaw attack, increasing the number of freeze/thaw cycles leads to deteriorating the properties of concrete, owning that to the weakened bond between aggregates and paste caused by the development of internal cracks in the cement paste with repeated cycles. Using high-quality aggregate and/or supplementary cementitious materials can enhance the concrete resistance to such issues. However, checking the compatibility of the used materials in terms of evaluating the air void characteristics is mandatory in particularly when the air-entraining agent is used. Fly Ash, blast furnace slag,

silica fume, and metakaolin are commonly used SCMs for the purpose of enhancing the performance of concrete. It is concluded that adding supplementary cementitious materials helps in resisting deleterious effects, such as alkali-silica reactivity, freeze/thaw deterioration, random cracking, and permeability.
