Influence of capillary properties and evaporation on salt weathering of sedimentary rocks

Abstract

International audienceThe importance of capillary imbibition and evaporation processes in the decay of stone through salt crystallization is estimated by different experiments adapted from the European standard EN 12370. The various tests consist in slightly modifying the salt (sodium sulphate) supply in the porous network of stones as well as the amount of evaporation and in checking the weathering evolution of the stone. The results show that ionic diffusion and dissolution of pre-existent salts are not efficient enough to imply supersaturation, hence to visually alter the stone. An exterior supply of salt is required. The influence of evaporation is clearly shown when evaporation process could not occur through a side of the sample. In this case, isolated sides are never subjected to weathering, even to simple salt efflorescence