ABSTRACT
Nordic Europe includes Denmark, Iceland, Norway, Sweden and Finland. The history of alkali-aggregate reactions and the geology are quite different in these countries (Table 7.1). The same is valid for the cement types used (see later). However, the environmental conditions are relatively similar (see later). Furthermore, to the author’s knowledge, only ASR is documented in structures (i.e., no cases of ACR are reported). Neither has lithium been used in any of the countries to mitigate ASR. Brief overview of the history of ASR and the geology in the Nordic countries. Country First reports on ASR damage When was focus put on ASR? First ASR regulations introduced Last update of the ASR regulations 1 Main types of alkali-reactive aggregates Denmark 1951 2 1954 3 I: 1960’s II: 1970’s 1961 4 1987 5 2004 Most aggregate sources contain reactive components in form of highly reactive opaline flint, calcareous opaline flint and more slowly reactive porous chalcedonic flint. Pessimum behaviour of opaline and opaline flint limestone. A content > approx. 2 % by volume in the sand fraction of highly reactive microporous flint is the main problem Iceland Early 1960s 6 (1976) Early 1960s 6 1979 7 2012 Several highly reactive volcanic, porous aggregates, mainly basalts. Rhyolite is also reactive. The finest fraction is more severe Norway 1978 8 About 1990 9 1993 10 1996 11 2004 Slowly reactive aggregates are spread over most of the country. The coarse fraction has in particular given rise to ASR damage Sweden 1975 12 Early 1990s 13 2008 14 2015 15 Aggregates containing opaline flint are locally present in the south-western part (Scania area with similar geology as in Denmark). Different slowly reactive aggregates are located in many regions Finland Late 1990s 16 About 2010 16 No 16 regulations No regulations Slowly reactive aggregates, similar as in Sweden and Norway, are assumed to be present in many regions in Finland (geological mapping of potential reactive aggregates is lacking)
More details are given in the various chapters for each of the countries
(Nerenst, 1952)
The first Danish R&D project on ASR was initiated in 1954 by ATV (Academy of Technical Sciences) based on in-situ investigations of Danish concrete structures. Extensive research work was later carried out in two phases, denoted I and II.
(Plum, 1961): Preliminary guidelines
(“BBB”, 1987): Requirements to aggregates and maximum allowed alkali content
(Swamy, 1992, 1st edition): Awareness of potential reactive aggregates in the early 1960’s. However, the first proof of serious ASR damages in Iceland was not obtained until 1976 when drilled cores were taken from the exterior walls of a concrete house
(Kristjánsson, 1979)
(Kjennerud, 1978)
(Jensen, 1993): Dr thesis. Extensive research work was performed on a national basis from the early 1990’s
(Lindgård et al., 1993): Norwegian ASR test methods
(Norwegian Concrete Association, 1996): ASR regulations (voluntary until 2001)
(Nilsson & Peterson, 1983)
(Lagerblad & Trägårdh, 1992)
(SS137003: 2008): Concrete – Application of EN 206-1 in Sweden
(SS-EN 12620: 2008; SS 137003: 2015)
(Pyy et al., 2012a)
