Monotonic and cyclic compression characteristics of CFRP confined masonry columns

The lateral confinement of masonry columns using composites have shown to improve their strength and ductility. Although, several research studies were focused on investigating the monotonic compression behaviour of confined masonry columns in the past, their cyclic compression characteristics, which are necessary for seismic and dynamic analyses, are not well investigated. Thus, an attempt has been made to experimentally characterise the confined masonry columns under monotonic and cyclic axial compression in this research. In total, 36 masonry columns were built and tested under monotonic and cyclic compression. Out of 36 columns, twelve columns were unconfined and tested under monotonic compression, while the rest of the columns were confined with Carbon Fibre Reinforced Polymer (CFRP) laminates and tested under monotonic and cyclic compression. The experimental results are presented in terms of observed failure modes, compressive strengths and stress-strain curves. Cyclic loading protocol was displayed to marginally reduce the compressive strength of CFRP confined masonry columns by 6% to 13% compared to the compressive strengths obtained through monotonic compression testing. The analytical models available to predict the monotonic stress-strain curves were used to predict the cyclic envelop stress-strain relationship of confined masonry columns. Finally, the best fit analytical model to predict the cyclic envelop compression behaviour of CFRP confined masonry columns has been proposed.