Repair and strengthening of reinforced concrete square columns using ferrocement jackets

Improved confinement of reinforced concrete columns

“…Kaish et al [9] presented untraditional ferrocement jackets for restrengthening square short columns. Mourad and Shannag [2] investigated the preload effect on RC columns strengthened with ferrocement jackets. Xiong [10] confined the plain concrete columns with ferrocement jackets including steel bars.…”

“…The more availability, lower cost and less need for advanced installation technique for steel meshes (EMM and WWM) make them predominant in developing countries. Steel meshes encapsulated in thin-wall mortar layer (ferrocement, [6]) were extensively used in repair and rehabilitation of existing concrete columns [2,3,[7][8][9][10][11]. The uniform distribution of reinforcement in mortar improves many engineering properties such as the ductility, crack resistance, in-plane strength and durability.…”

“…However, either the large spacing or close spacing between ties results in lack of confinement of concrete core. While low volumetric ratio of ties reduces the confinement of concrete core [2], high volumetric ratio of ties defects concrete continuity and creates a weak plane between the core and the concrete cover [3] besides creating construction problems due to the congestion of column cage with reinforcement. Welded reinforcement grids were used by Saatcioglu and Grira [4] and Kusuma et al [5] to reduce reinforcement congestion due to overlapping hoops, bends and bend extensions.…”

In-plane Shear Strengthening of Unreinforced Masonry Walls Using GFRP Jacketing

“…Some successful examples of ferrocement jacketing have been observed in concrete structures [5][6][7][8] as well as in masonry structures where ferrocement provided a considerable increase in ductility, improvement of crack resistance [9,10], and increased stiffness and load carrying capacity as well as increase of in-plane resistance [11][12][13][14][15].…”

“…The earliest techniques, the so-called traditional, consist of applying the reinforcement in form of: (i) filling cracks and voids by grouting; ii) stitching of large cracks and weak areas with metallic or brick elements; iii) external or internal post-tensioning with steel ties; iv) shotcrete jacketing; v) ferrocement and vi) center core etc. [3,4].Some successful examples of ferrocement jacketing have been observed in concrete structures [5][6][7][8] as well as in masonry structures where ferrocement provided a considerable increase in ductility, improvement of crack resistance [9,10], and increased stiffness and load carrying capacity as well as increase of in-plane resistance [11][12][13][14][15]. …”