The behaviour of reinforced concrete frames with masonry wall infills is influenced a lot by the stiffness and strength difference between the frame and the infill, causing early detrimental damage to the infill or to the critical concrete columns. The paper reports the results from shake table seismic tests on a full-scale reinforced concrete (RC) frame building with modified hollow clay block (orthoblock brick) infill walls, within INMASPOL SERA Horizon 2020 project. The building received innovative resilient protection using Polyurethane Flexible Joints (PUFJs) made of polyurethane resin (PU), applied at the frame-infill interface in different schemes. Further, PUs were used for bonding of glass fibre grids to the weak masonry substrate to form Fibre Reinforced Polyurethanes (FRPUs) as an emergency repair intervention. The test results showed enhancement in the in-plane and out-of-plane infill performance under seismic excitations. The results confirmed remarkable delay of significant infill damages at very high RC frame inter-story drifts as a consequence of the use of PUFJs. Further, the PUFJ protection enabled the resilient repair of the infill even after very high inter-story drift of the structure up to 3.7%. The applied glass FRPU system efficiently protected the damaged infills against collapse under out-of-plane excitation while they restored large part of their in-plane stiffness.

The seismic strengthening of buildings in earthquake-prone areas has been a hot topic in recent years, especially for masonry structures. Because there are so many masonry structures and because most were built before seismic codes existed, their seismic vulnerability is an unavoidable issue. Over the years, several methods for seismic strengthening of masonry piers and walls have been developed that may roughly be classified as traditional or modern. In this paper, an overview of the most commonly used and effective methods will be presented with an emphasis on modern methods based on a Fabric-Reinforced Cementitious Matrix. The advantages and disadvantages will be discussed from the point of view of usability, feasibility, and effectiveness. Finally, a comparison will be drawn between traditional and new methods based on composite materials.