A Novel Approach for the Synthesis of Eco-friendly Geopolymer Ternary Blended Mortar with GGBS, Sugarcane Bagasse Ash, and Sewage Sludge Ash under Ambient Curing Conditions

The Present work emphasizes preparing ternary blended geopolymer mortar by partial replacement of Ground Granulated Blast Furnace Slag (GGBS) with a precursor such as Sugarcane Bagasse Ash (SCBA) and Sewage Sludge Ash (SSA) with two different sodium silicate to sodium hydroxide (SS/SH) ratios to prepare an alkaline activating solution. The replacement of GGBS with SCBA and SSA varied from 0–30% by weight. Binary and ternary mortar mixes were tested for compressive strength and their morphological characters, it was found that 10% of SCBA and 20% of SSA incorporation in the binary mix resulted in a drop in strength which is less significant than other replacements for SS/SH ratio of 2.5. The ternary mix consisting of GGBS, SCBA, and SSA in the ratio of 70:10:20 respectively produced a compressive strength that is comparable with the control mortar having 100% GGBS after 28 days of ambient curing. X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FTIR) studies showed the presence of C-A-S-H gel and participation of precursor in the geopolymer reaction which resulted in enhancement of strength. The Toxicity Characteristic Leaching Procedure (TCLP) results for SSA-incorporated mortar proved the leachability of heavy metals is within the limits. The application of geopolymer mortar proved to be vital in the sustainable production of building materials such as pre-cast elements, masonry units, etc.