Appropriate measures can be taken to minimise the risk of durability failure due to freezing and thawing. All immature concrete must be protected if freezing temperatures are likely in the period after casting. It is inadvisable to cast concrete when temperatures drop below 2ëC on a falling thermometer unless specific precautions are taken for cold weather concreting (Pink, 1978; Murdock et al., 1991). Production of hardened concrete with adequate durability in freeze- thaw exposure conditions involves control of one significant parameter or a combination of control measures. Significant issues are the amount of water in the concrete, the ability of the pore network to accommodate expansion and the characteristics of the aggregates, especially their water absorption. This chapter reviews the freezing process in porous materials, factors of influence, the exacerbation of damage by deicing agents, use of air entrainment, test methods and specification issues.
Production of durable concrete in cold climates is readily achievable but it requires knowledge of the phenomenon and appropriate control measures where warranted.
