An experimental program was conducted to evaluate the effectiveness
of the proposed rehabilitation method for reinforced concrete
interior beam–column joints. The proposed rehabilitation
method is based on increasing joint shear resistance and reducing
forces transferred into joint core. Based on the observation and test
results, the following conclusions can be drawn.
(1) Beam–column joints under high axial load ð0:6Ag f 0
cÞ are
prone to failure at the joints with joint shear stress larger
than the maximum allowable stress as specified in ASCE/SEI
41 and buckling of longitudinal reinforcements.
(2) The proposed rehabilitation method using ferrocement jackets
with embedded diagonal reinforcements enhances seismic
performance of interior beam–column joints using
ferrocement with high strength mortar. Damage levels of
rehabilitated specimens are reduced as compared with that
of control specimen.
(3) Bonding between ferrocement and concrete can be
improved by installing anchor bolts at the interface. Anchor
bolts are effective to prevent delamination of ferrocement
and facilitate fixing of wire mesh for easy construction.
(4) Increasing the strength of mortar in ferrocement is a vital
factor for achieving higher strength, larger ductility, better
energy dissipation, and higher stiffness.
(5) Diagonal reinforcements installed in the joint reduce strains
in the longitudinal reinforcements. This has the benefit of
reducing joint shear stress and preventing bonding failure
of longitudinal reinforcements.
(6) A method to predict shear capacities of joints strengthened
by ferrocement jackets with embedded diagonal reinforcements
is proposed. The proposed method is limited to specimens
under high axial load.