Effect of different ions on dissolution rates of silica and feldspars at high pH

The dissolution kinetics of silica-containing minerals in aggregates influences strongly the process ASR concrete. In this paper, effect different ions on rates SiO2 (amorphous and quartz) feldspars at high pH values was studied by following increase silicon concentrations experiments with a novel approach measuring evolution scratches polished surfaces. second method avoided problem precipitation some systems, such as formation C-S-H when calcium present lithium silicates presence lithium. At values, lithium, sulfate increased silica feldspars, while iron, magnesium additional NaCl, KCl or CsCl showed no significant effect. contrast, aluminium slowed down significantly quartz, amorphous Na K-feldspar for all temperatures studies: 20, 40 60 °C.