The present research focused on evaluating the performance of
CFRP confined concrete cylinders having a characteristic low
unconfined concrete strength. Eighteen concrete cylinders were
casted and later on subjected to uniaxial compression test up to
their failure point. Wrap thickness (UW, SL and DL) and low unconfined
concrete strength (12.41 MPa and 16.55 MPa) were the parametric
variables during this research. The performance of the CFRP
wrapped confined cylinders was very similar in each series while
evaluating the stress–strain curves and failure modes. The experimental
work was carefully recorded and afterwards results were
tabulated and plotted as graphs for a better comparison, both of
which showed that confinement due to high strength carbon fiber
composite can appreciably enhance the ultimate strengths and
strains values for even low strength concrete cylinders. The outcomes
of the present research for the performance of confined concrete
were in good agreement with the previous studies reported
by majority of the researchers. In case of 16.55 MPa (2400 psi) concrete
cylinders, it was also noted that the enhancement in axial
stress and strain values due to CFRP wrapping, which causes the
delay in the lateral expansion, was lower than that for 12.41 MPa
(1800 psi) similar concrete cylinders when wrapped with same
number of CFRP sheets. Therefore, existing but seismic deficient
low strength concrete structures after being properly repaired
and retrofitted with CFRP could not only recover their original state
but also survive even larger potential earthquakes due to this
improved strength and ductility.