The weathering of the foundation of the Tholos of Asklepios at Epidaurus: experiments and modelling

The modeling of damage in natural building stones, used in historical buildings or sites, will be presented. The influence of moisture diffusion in porous stones will be analyzed in relation to their strength degradation. In particular, the case of a circular partially exposed foundation in Tholos of Asklepios in the archaeological site of Epidaurus (Greece) will be studied. In order to design the appropriate restoration measures, an analysis of the degradation process was realized. This is a chemo-hydro-mechanical process and it has been analyzed by means of a numerical code implemented by the authors. The Sharp Front Theory (SFT) has been adopted for the modeling of moisture diffusion, while the effects of weathering on the mechanical behavior are taken into account by introducing a scalar index related to seasonal variations of moisture. In order to validate the code, experimental tests have been carried out on specimens retrieved from the site. It is shown that the model calibrated with the presented experimental results can be considered as a useful tool to predict the process of degradation of the foundation of the Tholos and can be extended to predict the chemo-hydro-mechanical behavior of porous soft rocks of different kind.