ABSTRACT

It is reported that 1 .6 billion Tonnes of Portland cement 1s being used for the production of 12 billion Tonnes per year of concrete. The manufacture of one Tonnes of cement approximately emits 0.8 Tonnes of carbon dioxide into the atmosphere which contribute global warming. To reduce global warming, metakaolin or other cementitious materials are preferred to replace at least some part of cement. Such cementitious materials can be manufactured using wastepaper sludge, which is about 25% of total volume of paper after incineration. However, its optimal calcination temperature and duration are still uncertain. Therefore, this study was carried out to develop a cementitious material from wastepaper sludge at the optimal calcination temperature and heating duration. For that, moisture content, dry density, specific gravity, loss on ignition, compressive strength, chemical and mineralogical composition and strength activity index of samples were determined using standard methods. The percentage increase of chemical compounds in DWPS samples were Si02 21%, Ah03 66% and CaO 100% than the composition of WPS samples. The analysis of mineralogical composition showed that the calcite content in DWPS samples was increased by 52% as compared to constituent WPS samples. The composition of quartz in DWPS was decreased by 82%, which is a positive sign for the developed pozzolanic materials. Moreover, the strength activity index of sample (MIX ID E), which was calcined at 600°C for 3 hours heating duration showed better results than control mix with 1 02.22% and 102.71% higher values at 7 days and 28 days curing period respectively. All other MIX IDs showed lower strength activity index than MIX ID E. The results were also verified by means of X-RD analysis.
which yields maximum number of counts in MIX ID E as compared to all. other
calcined samples. Hence from the outcomes of this research study, it could be recommended that the optimal thermal activation of wastepaper sludge was at 600°C for 3hours heating duration and it may be replaced with some part of cement in concrete I mortar.