Darre, M. (2016)
Anvendelse af ny asketype – vurdering af væsentligste egenskaber Undersøgelse af slamaskens indflydelse på betons trykstyrke og egenskaber
BEng project
This report examines the possibility of replacing the cement with sludge ash from Mølleåværket.
Compressive strength tests were carried out according to EN 196-1. Mortars with coal fly ash and sewage sludge ash were compared. The setting time was studied.
Compressive strength tests gave good results for the mortars with sewage sludge ash and the compressive strength was the same as the reference without ash after 28 days of curing. When comparing the compressive strength at 28 curing days with 7 curing days it is striking that all samples with ash come closer to the reference without ash. This may indicate that this sewage sludge ash is a pozzolan, In addition, it was seen that mortar specimens with sewage sludge ash reach almost the same compressive strength as their references with fly ash.
The chloride content of the sludge ash meets the limit for fly ash, which is important if the concrete has to be reinforced. Furthermore, the loss on ignition for the sewage sludge ash was less than 5 %, which satisfies the standard limits.
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