Investigations into Replacing Calcined Clay with Sewage Sludge Ash in Limestone Calcined Clay Cement (LC3).

The effects of replacing calcined clay with sewage sludge ash (SSA) treated under room temperature and high temperature ranging from 500 °C to 900 °C in limestone calcined clay cement (LC3) have been investigated in this paper. The optimal calcination temperature for SSA was found to be 800 °C based on the results of strength and microstructure observations. The main inorganic components of sludge ash are FeO, SiO, AlO, and CaO, which are very similar to the components of calcined clay in LC3, but with a very high content of FeO (55-61%) and PO (9-10%).