Effect of Carbon Fibre Reinforced Polymer Strengthening on the Axial Capacity and Ductility of Non-slender Square Concrete Columns
Abstract
This research investigated the effect of Carbon Fibre Reinforced Polymer (CFRP)
strengthening on the axial capacity and ductility of non-slender square concrete columns. There
is a problem of buildings collapsing in Kenya. Retrofitting of the buildings vulnerable to
collapse is of great importance to ensure the safety of the occupants and to address the housing
deficit in the country. An experimental research programme was conducted on 95 non-slender
square concrete columns to find out the gain in axial capacity and ductility of the columns
strengthened by CFRP. The specimens (150mm x 150mm x 350mm) were made of plain and
reinforced concrete. Three different concrete grades: C8/10, C12/15 and C16/20 were used.
The specimen had varying configurations of CFRP wrap: partial and full confinement in one
and two layers. Four parameters are investigated in this study: concrete grade, steel
reinforcement, degree of confinement and the number of layers of CFRP wrap. The specimens
were subjected to uniaxial compression up to failure, and the stress-strain curves were plotted.
This study found that the weakest concrete grade experiences the highest effect due to CFRP
strengthening. Concrete C8/10 was 5.42 times more affected than Concrete C16/20 in terms of
axial capacity (542%) but the effect was comparable in terms of ductility. Plain concrete
specimens experienced higher effect in both axial capacity (114%) and ductility (145%) than
reinforced concrete specimens. Full confinement was more effective in both the axial capacity
(383%) and ductility (275%). Similarly, two layers was more effective in both axial capacity
(435%) and ductility (292%). Experimental design optimisation showed that, partial CFRP
confinement offers better material efficiency as compared to full CFRP confinement. These
findings are instrumental in developing a rationale and a design method for retrofitting existing
columns with CFRP wrap.
Citation
MUNYUA, MUTHOMI. SCHOOL OF ENGINEERING. Diss. Department of Civil & Construction Engineering, University of Nairobi, 2021.Publisher
University of Nairobi
Rights
Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
The following license files are associated with this item: