Bond properties of SRG anchors employed to improve the effectiveness of SRG/FRCM composites

Fiber reinforced cementitious matrix (FRCM) composites represent a newly-developed promising alternative to traditional materials for strengthening and retrofitting reinforced concrete and masonry structures. FRCM composites present several advantages with respect to fiber reinforced polymers (FRP) composites. However, while FRP composites have been extensively studied in the last decades and several design guidelines and analytical formulations are available, FRCM composites are still in their infancy and very few data are present in the literature. Thus, another issue that should be solved regards the stated need for the anchorage systems to improve FRP and FRCM strength in situations where debonding or lack of development length is a problem. In this study, the effectiveness of the anchorage system and the interaction with an externally bonded FRCM were studied on both concrete beams and masonry columns. The columns and beams were tested until failure condition in the Laboratory of Structural and Geotechnical Engineering (DICAM – LISG) of the University of Bologna, via del Lazzaretto 15/5, Bologna. Test parameters considered for this study are: density of steel fibers, type of anchorages and bending inclination of the fiber exerted as anchorage, respectively 45° for concrete beam and 90° for masonry column. Test results demonstrate that the introduction of additional anchorages improves the effectiveness of the FRCM composites in terms of resistance and loading capacity.