Mechanical Properties and Durability of Fiber-reinforced Concrete

Traditional methods of pasting carbon and aramid fiber sheets or boards on concrete are usually adopted for concrete reinforcement due to the high brittleness and poor toughness of concrete.However, many factors affect the use of these methods, and the characteristics of fiber materials are not maximized.This study proposed a test model in which chopped carbon, aramid, and hybrid carbon-aramid fibers (1:1) were directly added to concrete to fully utilize the high strength and toughness of fibers and improve the properties of concrete.The influence of different types and mixing ratios of fibers on the mechanical properties and durability of concrete was analyzed through axial compressive strength, static elastic modulus, and carbonation tests.A calculation model based on the axial compressive strength, carbon dioxide concentration, and carbonization time of concrete was developed with existing carbonation depth calculation models and verified using experimental data.Results demonstrate that the compressive strength, elastic modulus, and anticarbonization capacity of the fiber-reinforced concrete initially increase and then decrease with an increase in fiber content and are better than those of ordinary concrete.The compressive strength and elastic modulus of the hybrid fiberreinforced concrete with a mixing ratio of 1% increase the most among all of the studied concrete samples, and the anticarbonation capacity of the carbon fiber-reinforced concrete with a mixing ratio of 1% is the best.The proposed method provides a reference for practical property and durability evaluation of fiber-reinforced concrete in practical engineering.