Carbonation evolution of lime putty coatings with mussel shell aggregate

The carbonation process is studied from young ages up to 2 years in mortars with fine mussel shell aggregate. Mussel shell aggregate affects lime mortars due to its shape (angular and flaky) and texture (smooth), and also its microstructure consisting of 2% organic matter in the form of protein and polysaccharides (chitin). Its effect is analysed in pore structure, microstructure by SEM, carbonation by phenolphthalein, and mechanical strength by means of compressive strength and ultrasounds. Conclusions show that the use of mussel shell aggregate delays carbonation at young ages (28 days) while increasing the total carbonated area at longer ages (1 and 2 years). These two different trends can be seen in all of the properties analysed. (C) 2020 Elsevier Ltd. All rights reserved.