NON-CARBONATE ALKALI-ACTIVATED BINDERS UTILIZING NATURAL POZZOLAN, LIMESTONE POWDER, SILICOMANGANESE FUME, AND RED MUD

This study aimed to develop non-carbonate alkali-activated binders utilizing natural and industrial waste materials in addition to small quantity of ordinary Portland cement (OPC) as precursor materials. Precursor materials were activated using the mixture of sodium hydroxide and sodium silicate solutions. Initial trials were carried out to optimize the proportioning of the precursor materials and the levels of activation parameters and to select suitable curing regimes. Using three combinations of natural pozzolan and OPC and keeping percentages of other precursors and activation parameters invariant at their optimum levels and two selected curing regimes, six mixtures of alkali-activated concrete (AAC) were prepared. The AAC mixtures were tested to determine their microstructural and mechanical properties, drying shrinkage, and durability characteristics. Test results exhibited the significant effects of the percentage of OPC and curing regime on the properties of AAC with optimum performance at an OPC content of 20% and curing using steam.