Optimized Hybrid Carbon-Glass Textile-Reinforced Mortar for Flexural and Shear Strengthening of RC Members

The open mesh textile reinforcements used today in textile-reinforced mortar (TRM) strengthening applications are composed of identical fiber rovings in both orthogonal directions, regardless of the type of application. However, for reinforced concrete (RC) members, such as beams and columns, where fibers are utilized in one main direction, such textile geometry can lead to ineffective and excessive use of raw materials and, therefore, uneconomic design. This paper experimentally investigates the use of hybrid textile reinforcement for flexural and shear strengthening in 22 RC beams. Four types of hybrid textiles were designed and manufactured to allow for the environmentally friendly and cost-efficient use of the fibers. Expensive high-strength carbon and weaker glass fibers were used in the main and secondary directions, respectively. Hybrid carbon-glass textiles, which are composed of weaker glass fiber rovings with larger spacings in the secondary direction, showed similar effectiveness with the standard carbon textiles with 50%-50% weight distribution per direction. A cost estimation revealed that massive savings on raw materials can be achieved when hybrid layouts are used instead of conventional textiles. Therefore, the results of this paper could provide a new scope for the optimization of current TRM systems for various retrofitting applications and might assist in the development of a more economical, environmentally friendly, and balanced design of textile reinforcements.