1 CHARACTERISATION OF PORTLAND CEMENT BLENDED WITH PITCHSTONE FINES AIDING CARBON DIOXIDE EMISSION REDUCTION

Climate change and global warming present a significant challenge as unstainable levels of greenhouse gas emissions arising from human induced activities continue to be emitted. The cement industry is responsible for between 5 and 10 % of annual world carbon dioxide emissions; most arising from the manufacture of Portland cement (PC). An effective way of reducing emissions is by incorporating supplementary cementitious materials (SCMs) as partial PC replacements. SCMs are silicate or aluminosilicate based pozzolanic materials which, in finely divided form, combine with water and calcium hydroxide (lime), liberated by cement hydration, to form compounds exhibiting cementitious properties. Pitchstone is such an aluminosilicate and has the potential to act as an effective pozzolan in the partial replacement of PC. In North Queensland, Australia, a vast deposit of pitchstone is mined and processed for expandable perlite aggregate. During the classification stage of the excavated natural material, pitchstone fines (PF) less than 0.5 mm in size are generated, whic