Performance of cement-lime mortars against salt crystallization using experimental accelerated weathering tests

Abstract

This study investigates the resistance of six cement-lime mortar compositions against salt crystallization under accelerated weathering conditions. Sodium chloride (NaCl) and sodium sulfate (Na2SO4) solutions at various concentrations were used to simulate salt-induced damage, comparing the efficacy of two distinct salt crystallization testing protocols: the EN 12370 standard and a modified version of the newly developed RILEM TC 271-ASC recommendation adapted for mortars. Results demonstrate that cement-lime mortars exhibit a higher susceptibility to salt crystallization damage compared to pure cement mortars, when exposed to both NaCl and Na2SO4. The EN 12370 standard was found to induce unrealistic decay patterns, overestimating damage, while the adapted RILEM methodology produced more representative and quantifiable deterioration. This work highlights critical limitations of current standard methods and offers an improved, realistic approach for evaluating the durability of lime- and cement-based materials with various pore size distributions.