ALKALI-AGGREGATE REACTION IN SOUTHERN NORWAY

AAR of the type Slow/Late-Expansive Alkali-Silicate/Silica reaction has recently been diagnosed in numerous Norwegian dams, hydropower plants and road bridges. AAR has been caused by a generally high alkali content in Norwegian cements during decades and rock aggregates (coarse fractions) of rhyolite, sandstone, graywacke, argillite, quartzite, phyllite and cataclastic rocks (mylonite and cataclasite). Field inspections of 483 structures older than 10 years have revealed map cracking and volume expansions as significant for AAR in Norwegian structures. Furthermore map cracking has been observed in about 70% of investigated structures with an increased cracking tendency in structures built around 1950-1960. Significant for AAR in concretes are: Reaction rims in broken faces of reacted aggregates, dark peripheral zonation in aggregates (clarified rim), white reaction products precipitated in larger air voids and cracked aggregates and cement paste. Reaction products (gel and cryptocrystalline) occur in cracks in aggregate and cement paste and in air voids. To minimize the risk for AAR in future structures, the Norwegian Concrete Society has recently proposed a test procedure for aggregates used in concrete. (A) For the covering abstract see IRRD 871351.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0946691461
• Corporate Authors:

  THE CONCRETE SOCIETY

  FRAMEWOOD ROAD
  WEXHAM,   United Kingdom  SL3 6PJ
• Authors:
  • Jensen, V
  • DANIELSEN, S W
• Conference:
  • THE NINTH INTERNATIONAL CONFERENCE ON ALKALI-AGGREGATE REACTION IN CONCRETE, JULY 1992, LONDON, VOLUME 1
• Publication Date: 1992

Language

• English

Media Info

• Features: References;
• Pagination: p. 477-84

Subject/Index Terms

• TRT Terms: Aggregates; Alkali; Cement; Chemical reactions; Concrete; Conferences; Standards; Tests
• Geographic Terms: Norway
• ITRD Terms: 4577: Aggregate; 7353: Alkali; 4758: Cement; 4755: Concrete; 8525: Conference; 8084: Norway; 7156: Reaction (chem); 187: Specification (standard); 6255: Test
• Subject Areas: Data and Information Technology; Geotechnology;

Filing Info

• Accession Number: 00711226
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• ISBN: 0-946691-46-1
• Files: ITRD
• Created Date: Sep 20 1995 12:00AM