Local weather conditions have a significant effect on the deterioration rate of concrete buildings
Concrete buildings tend to deteriorate faster in coastal areas than inland due to heavy rainfall, frost damage and high winds.In addition, weather conditions explain why south and west facing facades are more vulnerable to freeze-thaw damage and the corrosion of reinforcing steel than north and east facing facades.
Rainfall has a crucial effect on the deterioration rate of concrete structures. Deterioration does not occur, if the façade or balcony is sheltered from rain or exposure to rain is very limited. Durability properties refer, among others, to the thickness, capillarity and porosity of the concrete.
The doctoral dissertation of Lic.Tech. Jukka Lahdensivu explores the durability properties and deterioration rates of Finnish concrete facades and balconies. The findings are based on the building inspections of 947 blocks of flats and the Finnish Meteorological Institute’s weather observations since 1961. The blocks of flats were built using precast concrete between 1960 and 1996.
The results demonstrate that blocks of flats that were built before the mid-1980s have the greatest risk of frost damage. The freeze-thaw durability of concrete structures has improved significantly from the 1980s onwards.
Corrosion damage is almost solely the result of carbonation. Carbonation occurs when carbon dioxide from the air penetrates the concrete and reacts with minerals to form carbonates. This reaction lowers the pH of the concrete and can cause the reinforcement bars to corrode.
“The lifespan of concrete facades and balconies built in the 70s and 80s can be significantly extended by using relatively light renovation methods, as long as protective coatings are used”, says Lahdensivu.
Public defence of a doctoral dissertation on Friday, 23 March
The doctoral dissertation of Lic.Tech. Jukka Lahdensivu in the field of renovation building “Durability properties and actual deterioration of Finnish concrete facades and balconies” will be publicly examined at the Faculty of Built Environment of Tampere University of Technology in room RG202 in the Rakennustalo building (address Korkeakoulunkatu 5, Tampere, Finland) on Friday, 23 March at 12:00.
The opponent will be DTech Jouni Punkki (Parma Ltd). Professor Matti Pentti from the Department of Civil Engineering will act as Chairman.
Jukka Lahdensivu (42) comes from Noormarkku, lives in Kangasla ana works as a research manager at the Department of Civil Engineering of TUT.
Further information:
Jukka Lahdensivu, tel. +358 (0) 400 733 852, jukka.lahdensivu@tut.