Abstract :Strengthening slender reinforced concrete (RC) columns is a challenge because
their sensitivity to overall buckling and the combination of the bending and
compressive stresses. This paper presents experimental study for strengthening twenty
long RC columns using enhanced ferrocement jackets. The column specimens have
slenderness ratio of 17.6 and two different cross-sections (square and rectangular).
The utilized expanded metal mesh layers have different weights, lengths and numbers
for each jacket. The twenty strengthened specimens and four reference non-jacketed
specimens were tested under concentric compression loading. The results
demonstrated the effectiveness of the ferrocement jacket in improving the column
capacity, increasing the stiffness, and reducing the lateral deformation. The
significance of the jackets is more evident for long RC columns with larger crosssection area, and for jackets with larger volume fraction of metal mesh layers at the
middle-third of the column height.