Portland State University. Department of Civil & Environmental Engineering
Date of Award
Doctor of Philosophy (Ph.D.) in Civil & Environmental Engineering
Civil and Environmental Engineering
1 online resource (xxiv, 293 pages)
Concrete columns -- Testing, Reinforced concrete construction -- Testing, Carbon fiber-reinforced plastics, Axial loads, Lateral loads
In the Middle East region and many countries in the world, older reinforced concrete (RC) columns are deemed to be weak in seismic resistance because of their low amount of reinforcement, low grades of concrete, and large spacing between the transverse reinforcement. The capacity of older RC columns that are also slender is further reduced due to the secondary moments. Appropriate retrofit techniques can improve the capacity and behavior of concrete members. In this study, externally bonded Carbon Fiber Reinforced Polymer (CFRP) retrofit technique was implemented to improve the behavior of RC columns tested under constant axial load and cyclic lateral load. The study included physical testing of five half-scale slender RC columns, with shear span to depth ratio of 7. Three specimens represented columns in a 2-story, and two specimens represented columns in a 4-story building. All specimens had identical cross sections, reinforcement detail, and concrete strength. Two specimens were control, two specimens were retrofit with CFRP in the lateral direction, and one specimen retrofit in the longitudinal and lateral directions. A computer model was created to predict the lateral load-displacement relations. The experimental results show improvement in the retrofit specimens in strength, ductility, and energy dissipation. The effect of retrofitting technique applied to two full-scale prototype RC buildings, a 2-story and a 4-story building located in two cities in Iraq, Baghdad, and Erbil, was determined using SAP2000.
Aules, Wisam Amer, "Behavior of Non-Ductile Slender Reinforced Concrete Columns Retrofit by CFRP Under Cyclic Loading" (2019). Dissertations and Theses. Paper 4804.