Influence of Sucrose on the Morphology of Calcium Hydroxide Crystals

While Portland cement is the most common binder used in constructions, the use of air lime in the modernconstruction industry can still prove to be advantageous for certain applications, if some limitations – mostlyrelated to the carbonation reaction – are overcome. Morphology and size of calcium hydroxide (CH) have animportant effect on its reaction kinetics and can be modified using organic additives. This study investigatesthe effects of sucrose on the morphology of calcium hydroxide. Sucrose is added to the lime, both before andafter the slaking. Scanning electron microscopy and X-ray diffraction were used to investigate the crystalssize and morphology in modified and control samples, while microchemical analyses were carried out toinvestigate the composition of pore solutions. Results suggest that sucrose, especially if added before theslaking process, affects the characteristics of CH crystals (habit and size) as well as the chemistry of thepore solution, with possible implications on thre activity and properties of sucrose-modified lime putty and, in turn, of lime-based construction materials