Carbonation process in lime pastes with different water/binder ratio

Abstract

Most research on binder carbonation is based on the analysis of depth changes in the carbonation front. Moreover, previous studies have dealt with mortars, where aggregatesplaya role in the variations in carbonation patterns. In the approach adopted in the present study, carbonation was determined in terms of the variation in weight resulting from CO2 absorption, anda new parameter(independent ofthe drying process), denominatedA, was established. This parameter was assessed in several lime pastes with different W/B (waterjbinder) ratios andits variations were correlated to paste microstructure. Due to the type of porosityprevaJ'ling in lime pastes, diffusion tookplace according to Fick~ law; water was retained notby capillarity butbysurface adsorption. Drying did not retard carbonation in lime pastes