Techniques and materials in use for structural restoration
Repair and strengthening of masonry walls are the most frequent types of intervention. Suitable techniques vary according to the type of masonry, the type of damage and the decision of re-establishing of the structural interconnection between external leaves and the core, in addition to the visual rejointing and filling of cracks. The injecting of grouts to fill cracks is the most usual and effective technique for masonry restoration. The insertion of stainless steel or fibre-reinforced polymer bars along the bed joints allows an increase of the tensile strength and the control of the horizontal deformation of the masonry. Columns built of masonry using bricks or cut stones present, due to seismic action, excessive compressive stresses at the top and bottom, as they rock during an earthquake. The use of grouting to consolidate loose or weak cores of rubble in three-leaf walls is the most usual and effective technique for masonry restoration.