The peculiar behaviour of low‐carbon concretes under salt frost exposure

Since the early days of concrete construction, the deterioration of concrete due to the combined action of frost, water and de‐icing salts had been observed. This salt frost attack is typically associated with surface scaling. The underlying mechanism for that damage was unresolved for many decades and many conflicting damage theories exist. In the past, that knowledge gap was primarily of academic interest, as a good salt frost scaling resistance of clinker rich concretes was easily achieved with air entrainment. However, as that approach increasingly reaches its limit for “low‐carbon concretes”, an in‐depth knowledge of the damage mechanisms can help to identify alternative measures to ensure good salt frost scaling resistance of such concretes. Based on a novel theory, which can explain important characteristics of salt frost attack and the generation of scaling damage, an additional cause for the unfavourable influence of clinker reduction on salt frost resistance were identified.