Laboratory investigations on fine aggregates used for concrete pavements due to the risk of ASR

Abstract

The assessment of the aggregate suitability for concrete pavements applies mainly to coarse aggregate. However, even fine aggregate can significantly affect the long-term durability of concrete when it is susceptible to alkali-silica reaction (ASR). The sustainable use of available fine aggregates for the production of concrete, while reducing the effects of ASR, requires special preventive measures. The paper proposed different procedures to determine the chemical composition of aggregate and the related ASR risk. The study covers various properties of natural fine aggregates from glacial deposits. The experiments included determination of chemical composition by prompt gamma activation analysis (PGAA), quantitative mineralogical characterisation on thin sections using digital image procedure (DIP) and expansion measurements in mortar bar test (MBT). The strong correlation of sand origin and its susceptibility to ASR was observed. Content of micro- and cryptocrystalline quartz in siliceous sand was found to have a crucial effect on its performance in AMBT. Highlights The different testing procedures to determine the chemical composition of aggregate and the related ASR risk are proposed. The ASR expansion of a various origin sands was studied. The origin of the siliceous sand has a significant effect on its alkali-silica reactivity. The max. content of reactive quartz regarding ASR is determined.