Hansen, E.Ø. (2015)
Trykstyrke og densitet for beton ved samtidig og delvis erstatning af cement og sand med træaske
BSc thesis (In Danish)
Wood ash from Køge Kraftvarmeværk is tested as partly cement, sand or simultaneous sand and cement replacement in mortar prisms. Neither cement replacement (5% and 10%) nor sand replacement (10%) resulted in mortar prisms with compressive strength at the same level as the reference for 7, 14, and 28 days prisms. The compressive strength of mortar with 5% cement replacement is though close to the reference and the lowest compressive strength is reached when sand is replaced. The ash has a soluble fraction of 24% per weight and the ash was washed in water to remove the soluble fraction. When replacing different percentages of cement and sand with washed ash simultaneously it is seen, that the compressive strength is directly related to the porosity of the mortar and the porosity is directly related to the total amount of ash.
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