Fibrous Geopolymer Adhesive Jackets for Confining of Reinforced Concrete Columns

Abstract

The strengthening and rehabilitation of reinforced concrete structures is an important issue all over the world. Fiber-reinforced composites (FRC) are mainly used for the strength and rehabilitation of concrete members. However, its use is limited due to its high price and environmental effects and its adoption of epoxy as an adhesive, where epoxy is considered inefficient at high temperatures and loses most of its properties. The solution to this problem leads to the use of low-cost locally available geopolymer adhesive paste, with the possibility of adding fibers to improve the mechanical properties. This paper presents the experimental results of the circular RC columns confined by carbon fiber reinforced geopolymer adhesive (CFRGA) with fibers at geopolymer adhesive (GPA). Variables included; Geopolymer adhesive with or without fibers and type of fiber added to GPA (micro steel fibers, carbon fibers, and polypropylene fibers) with the volumetric ratio of (2%, 0.4%, 0.2%), respectively. The results where it was found that confinement by carbon fiber reinforced fibrous geopolymer adhesive improved the columns compressive strength estimated by (215%) and the axial strain improved by (268%). When adding (micro steel fibers, carbon fibers, and polypropylene fibers) to the adhesive led to an improvement in the strength of about (16.1%, 8.4%, and 7.96%) respectively, compared with the confined RC column without fibers at (GPA). Finally, confinements by carbon fiber reinforced geopolymer adhesive are more suitable for use in strengthening and rehabilitation of RC columns in areas with a hot climate.