1. Ferrocement jackets have been utilized as an alternative
repair/strengthening technique for increasing the axial load
carrying capacity and ductility of tied reinforced concrete
columns. The investigation was limited to ferrocement
jackets containing two layers of ordinary Welded Wire
Meshes (WWM) encapsulated with 20 mm high strength
ferrocement mortar. The limitation in number of layers
was due to matters related to managing and handling the
WWM during wrapping the specimens.
2. Test results indicated that strengthening unloaded reinforced
concrete columns of 150 150 mm square cross
section and a height of 1000 mm, with two layers of
WWM ferrocement jackets showed about 33% and 26%
increase in axial load carrying capacity and stiffness respectively,
compared to control columns.
3. Test results indicated that repairing similar reinforced concrete
columns of square cross section preloaded up to 60%
and 80% of their ultimate load carrying capacity, with the
same jackets showed about 28% and 15% increase in axial
load carrying capacity as compared to control columns.
4. Test results indicated that repairing similar reinforced concrete
columns of square cross section preloaded up to failure
with the same jacket restored almost the original load
carrying capacity and stiffness of control columns.
5. The strengthened and repaired columns failed in a ductile
manner characterized by the larger area enclosed by the
load displacement curve at the end of the test compared
to a brittle failure in case of control columns. However,
the repaired failed columns showed a significant loss in
ductility due to the existence of cracks in failed columns.