Desulphurised residues effect on the porosity and pore size distribution of cement based pastes during the early ages of curing
This research is a part of a research concerned with the use of flue gas desulphurisation waste residues in construction applications. In this paper, some results on pore size distribution of cement paste containing desulphurised waste during the early stages of hydration are reported. The desulphurised waste used was a combination of 85% fly ash and 15% gypsum (by weight) and was referred to as simulated desulphurised waste (SDW). The SDW was chosen due to the variability in composition of actual desulphurised waste. The cement was replaced with 0%, 20% and 40% SDW (by weight). The water to powder ratio was 0.5. The binder consists of cement or cement and SDW. Paste specimens were cured only for 24 hours (i.e. 1 day). The porosity and pore size distribution of cement pastes with and without SDW are reported. Increasing the amount of SDW leads to an increase in the pore volume of the paste and an increase in the size of pore.