GUERREIRO, JOÃO1, FERREIRA, JOÃO2, GAGO, ANTÓNIO3, PROENÇA, JORGE4, CÓIAS, VITOR5, COSTA, PAULO6

1 PhD Student, Instituto Superior Técnico, DECIVIL, jg@civil.ist.utl.pt

2 Professor, Instituto Superior Técnico, DECIVIL. 3 Professor, Instituto Superior Técnico, DECIVIL

4 Professor, Instituto Superior Técnico, DECIVIL. 5 Civil Engineer, STAP S.A. 6 Civil Engineer, STAP S.A

Ultra-High Performance Plaster (UHPPl) is an innovative seismic strengthening solution for load bearing masonry wall structures. This solution consists of a lime based plastering mortar, reinforced with a carbon fibre mesh, applied on one (internal or external) or both wall faces. The reinforcing mesh is tied by an evenly spaced grid of connectors, going through the wall thickness, acting also as confinement devices.

UHPPl was devised as a compromise between mechanical performance improvements (both for in-plane and out-of-plane actions) and the three pillars of a correct rehabilitation of constructions with some heritage significance: authenticity, reversibility and reduced intrusiveness.

The existence of a well tied reinforcing mesh should greatly improve the flexural strength and deformation capacity of the walls, critical when these are subjected to out-of-plane forces and displacements. These improvements were assessed through an extensive out-of-plane testing campaign on strengthened full scale wall specimens, with different arrangements of the confinement connectors and different vertical load levels. The global performance indices for these specimens (e.g. strength, deformation capacity and energy dissipation) are presented, together with those of un-reinforced specimens, tested as references.

Keywords: Seismic strengthening, masonry wall structures, out-of-plane, UHPPl