Research On Corrosion Resistance Of PVA-FRCCs In High Concentration Of Chloride Environment

The corrosion of chloride ions is an important factor leading to durability deteriorationof concrete structures. To research transport mechanism of chloride ions in the material cansignificantly help improving the durability of material and structure. Polyvinyl alcoholfiber reinforced cementitious composites (PVA-FRCCs) is a new type of civil engineeringmaterial, its excellent mechanical properties and durability have been affirmed by manyscholars. The corrosion depth of chloride ion, concentration of free chloride ion andconcentration of total chloride ion were tested, experimental study, theoretical analysis andlifetime prediction were carried out. The study contents and conclusions are as follows:1. This paper studied the effect of chloride concentration in different proportion oncorrosion resistance of PVA-FRCCs. It is found that chloride ion corrosion depth ofPVA-FRCCs increased with chloride concentration increased notably.2. The relationship between PVA fiber volume fraction and a chloride ion corrosiondepth of PVA-FRCCs was discussed. Results show that the incorporation of PVA fibers caneffectively improve the corrosion resistance of PVA-FRCCs, but the improved effect doesnot continue with increment of PVA fiber volume fraction, and a optimum mix proportionexisted. A conclusion is drawn that incorporation of1.0%PVA is best from0%to2.0%.3. Binding capacity of chloride ion was analyzed. Results show that the concentrationof combined chloride ion increased with the increment of the concentration of free chlorideions. The complex adsorption phenomena took place in a higher concentration of chlorideions. Chloride curing capability decreased firstly and then increased with increment of PVAfiber volume fraction. Binding capacity of chloride ion was worst when PVA fiber volumefraction was0.5%.4. A model of total chloride ion concentration distribution and corrosion depth ofchloride ion along with the direction were established based on Gray GM (1,1) theory.Results show that the model had the higher accuracy and lower error, and the model can beapplied to simulate the chloride ion corrosion depth and ion concentration distribution.5. When chloride ion concentration was15%, service life of ordinary concrete wasapproximate336d, but the service life of PVA-FRCCs was longer and was2.1-3.2timesthan ordinary concrete. Service life of PVA-FRCCs with1%fiber volume fraction waslongest (1064d).