Performance-Based Design for Fiber-Reinforced Concrete: Potential Balancing Corrosion Risk and Strength

With the advent of new materials that possess enhanced properties, designing concrete mixtures targeting a certain strength is a misleading concept. Hence, shifting to performance-based design is becoming a global trend that allows more flexibility in selecting and proportioning concrete ingredients. This study investigates the potential of increasing electric resistivity for fiber-reinforced concrete (i.e., reducing corrosion risk) while maintaining adequate strength. The key parameters included mixture ingredients, electrical conductivity, and physical properties of the used fibers. Two categories of fibers were considered: conductive (steel fiber) and nonconductive fibers (i.e., polypropylene and nylon). These fibers were incorporated in concrete mixtures with and without silica fume. Compressive and splitting tensile strengths, rapid chloride penetration, bulk, and surface electric resistivity were evaluated for all tested mixtures in order to illustrate potential interactions. Results show that there is a high potential to achieve highly electrically resistant concrete with adequate strength through the use of nonconductive fibers. Moreover, results emphasize the beneficial synergistic effect of nonconductive fibers and silica fume in optimizing the performance. Developed relationships between mechanical properties and electric resistivity are anticipated to guide engineers in selecting suitable mixtures based on the targeted performance.