Application-oriented mix design optimization and characterization of zeolite-based geopolymer mortars

Abstract

In the present study, geopolymer mortar samples (ZGM) were prepared based on natural zeolites in which the effect of the addition of the MCI-2005 NS migratory type corrosion inhibitor was also evaluated through the compressive strength. Additionally, the design of the mixture was optimized using; two alkaline activators (NaOH 14 M and Na2SiO3) in different proportions, river sand as fine aggregate, curing time and temperature. All ZGM samples were characterized using quantitative X-ray diffraction, SEM-EDS, simultaneous TGA-DSC analysis, FTIR spectrometry and compressive strength. The best mixture and curing temperature, corresponding to activator/zeolite: 0.5, Na2SiO3/NaOH: 3, and 60 °C, was identified by the highest mechanical strength obtained after 28 days of aging of the synthesized specimens, which reached 17 MPa. The zeolite-based geopolymer mortars prepared can be used in real life applications due to acceptable compressive strength obtained, and the use of MCI-2005 NS favors the compressive strength in ZGM specimens at an early age up to 14 days.