Durability of columns strengthened with CFRP under moisture

Abstract

The use of Fiber Reinforced Polymers (FRP) is an attractive option for strengthening structures due to characteristics such as low self-weight, ease and versatility of application, high tensile strength, fatigue and corrosion resistance. Among the main strengthening techniques with FRP, the EBR (Externally Bonded Reinforcement) technique stands out, which consists of applying strengthening materials through external bonding, exposing the composite to aggressive agents and the consequent loss of durability when not protected. Thus, this work is based on the temporal analysis of short reinforced concrete columns externally strengthened with carbon fiber sheets when exposed to moisture in non-accelerated testing. The results indicated an increase in load capacity in the strengthened elements with the increase in the number of layers of reinforcement material. In addition, the elements strengthened with continuous sheets showed better performance than those with discrete confinement, regardless of the variation in the number of layers. However, a reduction in the maximum mean tension was observed after exposure to humidity for 24 months.