Advanced Strategies and Materials for Reinforcing Normal and Disturbed Regions in Brick Masonry Columns

Abstract

This work presents the results of an experimental investigation on the behavior of 42 solid clay brick masonry columns internally strengthened by fiber-reinforced polymer (FRP) fabrics or stainless steel grids placed in horizontal mortar joints. In some cases, every course, and in other cases, alternate courses were reinforced with steel grids, carbon, and basalt FRP fabrics. Monotonic compressive loading tests were carried out under concentric and eccentric loads. Eccentric tests were carried out by loading the specimens on a reduced area with respect to the entire cross section, producing a disturbed region (D-region). A detailed characterization of the constituent materials was made experimentally. The compression tests show the effectiveness of the proposed strengthening techniques to produce increases in strength and the energy required for collapse of brick columns under concentric loads. Under eccentric loads, the reduction in the load-carrying capacity owing to the reduced loaded area is attenuated by the presence of the transverse reinforcements. An analytical expression is proposed that gives the strength of clay brick masonry columns considering that the biaxial strength domain of the bricks is modified because of the tensile contribution provided by the presence of transverse reinforcements. Moreover, a strut-and-tie model was utilized to calculate the load-carrying capacity in the D-region and was verified against experimental data, with good agreement.