Repair techniques for creep and long term damage of massive structures

In the paper, the main results of experimental researches carried out in the last years on the characterization of the bed joints reinforcement technique are presented. The technique is particularly effective for repair and strengthening of overstressed massive structures as towers, curtain walls, pillars, etc. which can suffer, during their service life, creep and long term damage. Several experimental work have been conducted aimed to select the most proper materials (reinforcement, mortars) and to characterize the masonry in the strengthened and/or repaired situation. In particular, the use of reinforced stainless steel and of innovative CFRP (Carbon Fiber Reinforced Polymer) has been considered as reinforcement element. As for the repointing, a large range of materials have been studied: hydrated lime and hydraulic lime-based mortars, additived or fiber-reinforced mortars and epoxy resins. Results have been compared in terms of global mechanical performances of the masonry but also in connection with many of the further significant aspects involved, as: feasibility of the technique, easy execution, compatibility with original materials, durability, aesthetics. Finally, some in-situ applications performed on historic building or structural components are shortly described