Stainless Steel Grids for Confinement of Clay Brick Masonry Columns

Abstract

This work presents the results of an experimental investigation on the behavior of 21 solid clay brick columns internally strengthened by stainless steel grids placed in the horizontal joints of mortar. This reinforcing technique can be applied as a constructive technique for new construction or as a retrofitting technique for existing structures (old structures to be reconstructed by original constructive method and internal reinforcement). Monotonic compressive loading tests were carried out under concentric and eccentric load. The effects of different numbers of steel grids and eccentricity of the external load were examined. Also, a detailed characterization of the constituent materials was made experimentally. The compression tests show the effectiveness of the proposed strengthening technique, which proves to be able to produce the increases in strength and energy required to collapse brick columns under both concentric and eccentric loads. To provide an analysis method for practical applications, an analytical expression is proposed that gives the strength value of confined brick columns by considering that the biaxial strength domain of the bricks is modified due to the tensile contribution offered by the presence of steel grids. Moreover, moment-axial force domains, derived using the plane cross section theory, are calibrated on the basis of the compressive strength values experimentally detected.