Study on chloride penetration resistance of hybrid fiber-reinforced concrete in winter construction: Fid-Bau Portal

Study on chloride penetration resistance of hybrid fiber-reinforced concrete in winter construction

Li, Yi / Qi, Mudan / Ji, Shengpeng

Chloride penetration resistance is an important indicator of durability, while the tortuosity of the pore structure affects the penetration path of chloride. However, the actual migration paths of chloride are complex and numerous, obtaining the actual migration path is a difficult process. This study proposed to quantify pore tortuosity using the shortest penetration path obtained from pore structure scans, investigated the mechanism of the effect of winter construction curing measures and fibers on the chloride penetration resistance based on the pore tortuosity. Three types of concrete were prepared: plain concrete (C), basalt-polypropylene fiber-reinforced concrete (BP) and steel-polypropylene fiber-reinforced concrete (SP), three curing conditions were set up in severe cold conditions: no winter construction curing measures (NWCM-1), adoption of winter construction curing measures (AWCM-2) and standard curing measures (SCM-3). Pore structure scans were performed and chloride migration coefficient were tested, the shortest penetration path and pore tortuosity were calculated. This study used the chloride migration coefficient as the basis for evaluating durability, experimental results showed that the highest durability was obtained by the adoption of winter construction curing measures. The pore tortuosity was calculated based on the shortest penetration path of chloride, was highly negatively correlated with the chloride migration coefficient, with a relevant coefficient of 0.902. Winter construction curing measures improved durability by reducing the porosity of the material and increasing the pore tortuosity. Adding fibers had the opposite effect.