On the memory effect of limestone for air pollution

During the last decade, there have been several reports in the literature on the “memory effect of building stones”, indicating that the stone erosion rate depends also on the environmental conditions the stone has experienced in the past. The present study checks whether this effect exists. A network of microcatchment units, exposing Massangis stone slabs to ambient atmospheric conditions, has therefore been set up througout Belgium. Runoff water fromt the stome specimens was collected on a weekly basis. The limestone slabs were switched between sites with different pollution levels, and their material loss rate trends examined. The rate of stone loss distinctly changed after the displacement, indicating an immediate adaptation of the stone to the new environment. Hence no evidence for a memory effect could be found.