Use of alternative ashes in concrete. With focus on Greenlandic fly ash

This work is focused on use of a municipal solid waste incineration (MSWI) ash from Sisimiut, Greenland. The experiments indicate that fly ash from Sisimiut is useful in concrete. After 42 days it shows that when 5% of the cement is replaced by ash it obtains a higher compressive strength than the reference. This result is statistically significant. When 10 % of the cement is replaced by ash it obtains a compressive strength that corresponds to the reference. It is observed that the development of the strength for mortar samples containing ash increases more relative to the reference mortar after 28 days. However, it is noted that the ash contains a very high amount of salts, in form of sodium chloride and calcium chloride, which implies that the concrete cannot be reinforced, because of the oxidation of iron. Environmentally the ash is also found to be very useful, since only very small amounts of heavy metals, are washed out from the mortar and the results are close to those from the reference. Because of the contents of carbon, both the ash and the mortar samples have different levels of black.

Download report