干旱区生态环境知识资源中心

A major problem in stone restoration is the reassembling of crackedstones using mortar and grout. The usual criteria for selection of products are related to chemical (free soluble salts), petrophysical and mechanical properties (absorption of water, porosity, elasticity modulus, compressive and traction strength resistance, adherence and hardness). Because in semi-arid environments stones are subjected to high hygric and thermal gradients, current validated solutions could be less durable or unsuitable. Several investigations underline the importance of dilation as a mechanism of damage and stone decay. The set up of a method related to thermal and hygric dilation measurements is presented. Dilation is linked to structural parameters of the materials and represents a significant physical property to assess stone-mortar compatibility. The study has been undertaken for the treatment of cracked limestones from the archaeological sites of Djemila (Algeria) and Volubilis (Morocco).