Iceland engineers confirm volcanic ash's binding, AAR-quelling properties.htm

Iceland engineers confirm volcanic ash's binding, AAR-quelling properties

Jun 2, 2010 12:45 PM

Sources: Mannvit Engineering, Reykjavik; CP staff

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 percent 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 percent portland cement) and ash (5 percent portland cement substitution) mixes. After the bars' 14-day exposure in a NaOH solution, Centre founder Børge Johannes Wigum (wigum@mannvit.is) observed dramatically lower AAR expansion in the ash (0.02  percent) versus the control (0.45 percent) specimens.

According to Mannvit Concrete Scientist Karsten Iversen (karsten@mannvit.is), 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

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