Corrosion Processes of Steel Reinforcement in Concrete Structures Based on Secondary Resources of Metallurgical Production

Abstract

The study of the influence of the physical and mechanical properties of concrete on various hydraulic binders on the corrosion resistance of steel reinforcement has been carried out. As a binder, the following were considered: CEM I 42.5 N and a slag-alkaline binder (SAB) based on ground granulated blast-furnace slag of Novolipetsk Metallurgical Plant (NMP). For comparative tests, concretes of class B 25 (M300) were used on granite aggregate with a fraction of 2,5-7,5 mm. Indicators of physical and mechanical properties such as: compressive strength, porosity, water absorption coefficient and weight loss coefficient of reinforcement at the age of 28, 90 and 180 days are criterial. 5 % aqueous solutions of NaCl, Na2S04 were used as working media in assessing the corrosion resistance of reinforcing steel; MgS04. It has been established that steel reinforcement in slag-base concrete (SBC) has high corrosion resistance, both in an aqueous solution of NaCl and in solutions of Na2S04 and MgSO4. Slag-alkali concretes are characterized by low porosity, lower water absorption coefficient in comparison with concretes based on Portland cement.