Achieving a suitable hygro-mechanical compatibility between the substrate and the repairing mortars in historic masonry constructions

Abstract

It is essential the study of restoration mortars on historical construction, because these must provide protection against harmful agents and must be sacrificable, not to cause damage on the primitive materials in case of removal by a new valorization. Repair mortars must have physical, chemical and mechanical compatibility with the substrate where they are applied and their mechanical strength must be similar to that of the wall where they are applied. The presence of water generates serious deterioration in the constructions, affecting its durability and causing greater maintenance and replacement costs for damaged materials. The characteristics of the repair mortars must be such that they do not allow water to enter the external faces and allow the evaporation of the water on internal faces. In this work the characteristics of compressive strength of different composition mortars have been evaluated; absorption, speed of capillary suction and air permeability. The results obtained can facilitate the choice of mortars for the rehabilitation of heritage buildings.