The International Centre of Research and Applied Technology for Alkali Aggregate Reactions has confirmed AAR-mitigating potential in ash from April’s Eyjafjallajökull volcano eruption, crediting the material’s particle fineness and approximately 60% silicon dioxide content. Using methods from ASTM C 1260 Multi-Laboratory Study of the Accelerated Mortar Bar Test for Alkali-Silica Reaction, staff at the Mannvit Engineering-housed facility prepared specimens from control (100% portland cement) and ash (5% portland cement substitution) mixes. After the bars’ 14-day exposure in a NaOH solution, Centre founder Børge Johannes Wigum (This email address is being protected from spambots. You need JavaScript enabled to view it.) observed dramatically lower AAR expansion in the ash (0.02%) versus the control (0.45%) specimens.

According to Mannvit Concrete Scientist Karsten Iversen (This email address is being protected from spambots. You need JavaScript enabled to view it.), the ash’s chemical composition is similar to fly ash, adding that she and colleagues also examined grain-size distribution compared to portland cement and fly ash, plus fresh and hardened mortar properties. Test results indicate that the volcanic ash, if feasible to quarry, could have potential as a concrete additive.

— www.manvit.is