Laboratory models for the assessment of the effectiveness of chemical damp-proofing in masonry: existing methods and some proposals for new fixtures

Coping with rising damp in existing masonry is extremely complex due to several reasons, such as the presence of architectural constrictions, the variability of ancient materials and technologies and the difficulty of monitoring moisture in a quantitative and accurate manner. For this reason, investigating the effectiveness of the different repair systems at a laboratory scale may greatly contribute to a better understanding of the functioning of such systems and to their improvement. In the case of chemical damp-proofing, some methods have been proposed in the literature and by national Institutions, but the approach followed by these methods are very different and not homogeneous. In the present paper, a review of the methods for the assessment of the performance of chemical damp-proofing by use of laboratory models is carried out, highlighting their strong points and drawbacks. Then, two new kinds of masonry models, characterised by different geometry and size, are proposed, allowing the reproduction of rising damp occurrence in the laboratory. Some preliminary results are shown about their employment for the monitoring of rising damp, also highlighting some critical aspects connected to their conditioning.