The Behavior of Geopolymer Mortars Based on Industrial Sludge Exposed to Aggressive Mediums

There is a growing interest in geopolymer materials. One of its advantages is the possibility of reusing a wide range of industrial waste. This paper aims to study the effect of the molar ratio H2O/Na2O(t) on the physical, chemical, and mechanical properties of industrial slurry-based geopolymers mortars and to evaluate the behavior of the synthesized mortar, which has the shortest setting time, in aggressive mediums. Structural changes in geopolymer mortars were monitored by X-ray diffraction (XRD) and Raman spectroscopy. The morphology of the samples was monitored by the Scanning Electron Microscope (SEM). SEM micrographs of geopolymer mortars show an intimate bond between sand grains and geopolymer cement. The compressive strength of geopolymer mortars varies significantly with the molar ratio H2O/Na2O(t). The mass loss of geopolymer mortars immersed in hydrochloric acid and sulfuric acid is more than that immersed in other solutions but lower than that of Portland cement-based mortars immersed in the same solutions.