BEHAVIOR OF HIGH-STRENGTH FIBER CONCRETE COLUMNS REINFORCED WITH GLASS FIBER-REINFORCED POLYMER BARS AND STRENGTHENED BY CARBON FIBER-REINFORCED POLYMER WRAP

Abstract

The solution of using glass fiber reinforced polymer (GFRP) bars, as reinforcement in concretestructures to overcome the problems created by steel reinforcement, is now widely accepted because ofboth its low cost and good results shown by large investigation efforts. In this paper twelve tests had beenconducted on reinforced concrete column specimens of (120 x 120 x 1000 mm effective dimensions)equally enlarged from both ends for the purpose of applying eccentric load, three specimens were madeof high strength concrete , reinforced with traditional deformed steel bars and stirrups to be considered asreferences, while the remaining nine specimens were of high strength concrete with 0, 0.5, 1.0% steelfiber, reinforced longitudinally with GFRP bars and wrapped with carbon fiber reinforced polymer(CFRP) textile replacing the steel stirrups .In addition to the similarity in behavior under load and in thefailure patterns of the specimens reinforced with GFRP bars and the specimens reinforced withtraditional steel, the results show that Steel reinforced columns has 13% higher ultimate load thancorresponding GFRP reinforced columns, also an approximate linear increase in the first crack andfailure load with the presence of steel fiber in concrete in range from 20% to 42% for 1% fiber contentand in range of 21% to 26 % for the first crack and ultimate load respectively . The ductility of thespecimen reinforced with GFRP bars is 90% higher than that of steel reinforced specimens of =2.18%and 10% more for those of =5.58%.