Strengthening of Masonry Elements with FRP Composites

ABSTRACT

The worldwide engineering community has identified failures of URM walls as one of the major causes of material damage and loss of human life due to seismic events. Therefore, the development of effective and affordable retrofitting techniques for masonry members is an urgent need. Fiber Reinforced Polymer (FRP) composites provide solutions for the strengthening of URM walls subjected to in-plane and out-ofplane overstresses caused by high wind pressures or earthquake loads. The presented research, part of the effective collaboration between the Department of Construction and Transportation (DCT) of University of Padua (Italy) and the Center for Infrastructure Engineering Studies (CIES) of University of Missouri-Rolla (U.S.A.), deals with the mechanical behavior of masonry walls strengthened with FRP composites and subjected to out-of-plane and in-plane loading. Two series of walls were tested for this research study. The first series studied the behavior of masonry wallettes under out-of-plane loads; the second series analyzed the performance in terms of shear capacity of masonry panels. FRP composites in the form of laminates and rods were used as strengthening materials. The results showed that both flexural and shear capacity of masonry walls can be notably increased by strengthening with FRP composites. A strengthening method denominated “FRP structural repointing” demonstrated that besides increasing the wall capacity it can preserve its aesthetics. Analytical models to predict the behavior of strengthened walls, as well as provisional guidelines to design the FRP strengthening for shear and flexure are also presented. Finally, conclusions are provided and future research needs on the area of masonry strengthening are outlined.