Strengthening of Modified Reactive Powder Concrete Columns with CFRP

An experimental investigation was conducted to investigate the behavior of ultra-high strength modified reactive concrete (MRPC) columns before and after strengthening with carbon fiber reinforced polymer (CFRP) sheets jacketing under eccentric axial load. Twelve columns were tested up to failure, strengthened and retested in order to examine strengthening efficiency and to evaluate the effects of variation of the concrete type (normal or MRPC), presence of steel fibers and main steel reinforcement ratio. Experimental results showed that CFRP jacketing increases the ultimate failure load of strengthened columns up to 185%, highly stiffens them (reduces lateral displacements) and allows more ductile failure than the original columns. Also, inclusion of steel fibers in MRPC columns increases failure loads up to 83%, prevents spalling of the concrete cover and increases the ductility.