Compressive strength optimization of geopolymer mortar made from alkaline liquid comprising acidic water

Abstract

Potable water is required for survival, and when demand exceeds supply, preserving every drop makes logical sense. The purpose of this study is to identify the optimal levels of selected processing parameters to maximize the 28 days compressive strength of geopolymer mortar created using alkaline liquid comprising hydrochloric acid. In order to maximize the 28 days compressive strength of geopolymer mortar, Taguchi's experimental design technique has been used for optimizing control process parameters. Experiments were performed using an orthogonal array L25 (35) comprising three control parameters, all with five-stages. Demineralized water that has been spiked with various amounts of hydrochloric acid (laboratory produced synthetic water), sodium hydroxide solution of varying molarity, and different alkaline liquid ratios were used as control processing parameters. To evaluate the impact of selected control processing settings on compressive strength, the signal-to-noise ratio, analysis of variance, and characterization test analysis (x-ray diffraction) were employed. The optimum processing conditions were found to be 100 mg/L HCl in demineralized water, 12 M NaOH solution, and 0.5 ratios of alkaline liquid, resulting in a maximum compressive strength of 34 N/mm2 after 28 days. Additionally, from characterization testing, it was evident that the inclusion of HCl in the matrix did not result in the development of a new phase.