Behaviour of Uniaxial Reinforced Concrete Columns Strengthened with Ultra-High Performance Concrete and Fiber Reinforced Polymers

This article investigates the behaviour of strengthened concrete columns using jacketing ultra-high-performance fiber reinforced (UHPFRC) and carbon fiber-reinforced polymer (CFRP) under uniaxial loaded. The jacket was connected to column core shear connectors fixed as a strip on tension zone between cores jacketing. Seven samples square cross-section (120 x120) mm at midsection with overall length 1250 were cast normal strength (NSC) having similar longitudinal transverse reinforcement. made tested axial load eccentricity equal 120 up failure. Test parameters thickness jackets (25 35) width CFRP (0,8, 12) cm. Column specimens tested, one them reference without any strengthening, other divided into two groups (A, B), each group included three based parameters. Group (A) has UHPFRC 25 cm respectively, (B) 35 respectively. outcomes show that increasing jacket, lead increase in carrying capacity about (110.5%,168.4%, 184.2%) for A, (157.9%,226.3%, 263.2%) B compared due delay appearance cracks their distribution. mid-height lateral displacement decreased (66.6%,42.3%, 35.9%) (46.15%,38.46%, 32.3%) B, also deformation (71.7%,60.86%, 55.86%) (65.5%,60.5%, 53.4) column. ductility only increased (13.67%,19.66%) thickness(25,35) because contented steel fibers, percentage decrease (5.1%,and 12%) (A), (1%,and 9.4%) when bonded (8 ,and results improvement initial secant stiffness when, size modulus elasticity. toughness (273.97%,301.55%, 304.5%) (453.69%,511.93%, 524.28%) cracks.