Evaluation of Sulfate Resistance of One-Part Alkali-Activated Materials Prepared by Mechanochemistry

Abstract

In this paper, the resistance of mechanically prepared one-part alkali-activated materials to external sulfuric acid attack was investigated by simulating realistic erosion environments in terms of sulfate type, concentration, and erosion mode. The macroscopic properties of the specimens were measured at different ages. Microscopic analyses were performed by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), and other techniques to obtain the effect of different erosion environments on the mechanical-force chemically prepared one-part alkali-activated materials against sulfate erosion. The study shows that the mechanical properties of the specimens showed a trend of increasing and then decreasing with the extension of erosion time. Compared with Na 2 SO 4 erosion, the erosion damage was greatest when the sulfate containing Mg 2+ was eroded in a wetting-and-drying cycle; the erosion products of Na 2 SO 4 solution coexist in the form of calcite and gypsum, while the erosion products of MgSO 4 solution mainly consist of gypsum.