Durability demands related to frost attack for Finnish concrete buildings in changing climate

摘要

In this study a database of concrete material properties and observed degradation was combined with climate data projections. Due to the predicted increase in precipitation, facades will receive more driving rain in the future. Though the number of freeze-thaw cycles is about the same in the southern coastal and inland areas, the amount of rain is remarkably higher in the southern coastal areas which increases the risk of frost damage. South-facing facades will continue to be most susceptible to climate stress which should be taken into account in designing the details of concrete facades and balconies. As concerns frost durability, climatic conditions in southern Finland will ease remarkably already in 2030. In inland areas outdoor climate will remain the same as presently but in the southern coastal areas conditions will get more severe with the increasing amount of rain and sleet almost to the end of century. Properties that influence degradation initiation time are highly important in ensuring proper service life of a structure. Failure with air entraining fresh concrete results in early frost damage to concrete, i.e. air entrainment of fresh concrete must always be done. Present requirements are sufficient for the future climates.