Abstract:
Pakistan is still striving for improvements in construction industry. Major construction
in private sector is carried out as non-engineered; there are very few projects that are
properly designed for gravity and lateral loads, which is main cause behind deaths in
major earthquakes. For example, Kashmir-Hazara (2005) earthquake caused deaths of
85,000 people. Nevertheless, after the Kashmir-Hazara (2005) earthquake, the
government and engineering commission stressed on execution of a seismic code.
Flat-plate and Flat-slab structures possess major advantages over conventional beamcolumn
supported frame structures because of absence of deep beams these structures
have freedom in building layout, lesser construction time, architectural, efficient and
economical parameters. These structural systems are significantly more flexible and
have less stiffness.
Two-storey representative commercial building was selected for analysis, which is
common practice in Rawalpindi-Islamabad region. Frame (having both columns and
beams) structure was taken as a baseline and Flat plate and slab were compared with it.
After doing Push-over analysis of these structures results showed weak behavior of flat
plate and slab which was quantified using the backbone curves of these structures.
CFRP (Carbon fiber reinforced Polymers) fabric was wrapped on concrete cylinders
casted in lab and compression test (ASTM C39) along with strain monitoring
mechanism was done to achieve stress-strain curve of wrapped and unwrapped
specimens. In order to model CFRP fabric being applied in potential plastic-hinge zone
of the columns of flat plate and flat slab structures plastic hinge properties of columns
were modified according to moment curvature curve of the column section and these
retrofitted structures were again analyzed and results were quantified to compared these
retrofitted structures with non-retrofitted structures and with frame structure.
