Aar in Precast Concrete Wall Elements

This paper investigates defects (pop- outs) in precast concrete facade, caused by Alkali- aggregate reaction (AAR) on insulated wall elements, which were produced in Lithuania and shipped to Sweden. Links between climate data and AAR were found, samples from the site taken and studied with optical microscope. Information about concrete composition, aggregate granulometry and AAR risk discussed. Finally, possible AAR preventive measures for such production technique discussed and repair of the facade described.