Synergistic effect of carbonation and dry–wet cycles on the adhesion, elastic modulus, and dimensional stability of rendering mortars – A multiscale approach

Abstract

This study explored the combined effects of drying and wetting cycles with carbonation aging on rendering mortars and investigated mechanical properties, bond strength, dimensional stability, and durability at the macro and nanoscale levels. The rendered mortars were evaluated individually and applied to a ceramic substrate. The prepared samples were cured for 150 days, carbonated (5 % CO2 and an RH of 60 %), and underwent 20 drying–wetting cycles. Carbonation shrinks the mortar, which can be completely reversed after the first drying–wetting cycle. Exposing the mortar to drying–wetting cycles suppresses the improvements in the bond strength and modulus of elasticity attributed to carbonation. The nanoscale tests confirmed the results measured in the macroscale. In conclusion, this paper showed that changes in the render caused by carbonation may be reversed after wetting and drying cycles.