BEHAVIOR OF COMBINED FIBER-REINFORCED CONCRETE UNDER THE ACTION OF DE-ICING AGENTS

Abstract

De-icing agents such as sodium, calcium, and magnesium chlorides are widely used to ensure the safe operation of road surfaces during the winter period. However, their use has a significant impact on the durability and mechanical properties of concrete and fiber-reinforced concrete pavements. Studies show that the effect of chloride-based agents leads to a partial decrease in concrete strength due to the penetration of chloride ions into the porous structure, which promotes corrosion of reinforcing fibers and metallic components. In fiber-reinforced concrete with combined fibers, this effect is partially compensated by a more uniform load distribution and increased material density. At the same time, aggressive environmental conditions, particularly the influence of saline solutions and de-icing agents (chlorides and sand-salt mixtures), can significantly affect the physical and mechanical properties of fiber-reinforced concrete, its durability, and its resistance to cracking. Therefore, studying the material’s resistance under such conditions is essential for assessing its suitability for road and civil construction applications. The increased resistance of fiber-reinforced concrete compared to concrete without fibers under the influence of de-icing agents is achieved through the combined introduction of steel and polypropylene fibers. Ordinary concrete exposed to salts, particularly de-icing agents such as sodium and magnesium chlorides, can lose up to 30% of its strength after just 90 days. The use of combined fibers of different sizes increases the contact area within the cement matrix, enhances the structural density, and slows the development of microcracks in the substrate caused by chloride corrosion, while simultaneously reducing the rate of chloride ion migration. This helps to slow the penetration of saline solutions and other chemical agents into the depth of the samples, which significantly increases the durability of the structures. Further research will make it possible to optimize the composition of fiber-reinforced concrete for various operating conditions of road and airfield pavements.