Study of Steel Rebar Corrosion in the Building for Preparation of H_2SO_4 Solutions at Trepca Battery Plant in Mitrovica

摘要

Degradation of concrete structures from corrosion in industrial facilities represents a major infrastructure problem. In non-industrial environments degradation of reinforced concrete in most cases is due to carbonation and the presence of chloride ions, while in industrial facilities such degradation can be caused by other aggressive substances specific for that industrial environment. The presence of sulphate-rich solutions also damages concrete structures and causes corrosion of steel in concrete. Degradation of reinforced structures from the presence of sulphate can be clearly observed in the facility for the electrolyte preparation (dilute sulphuric acid), of "Batteries Plant of Trepca" in Kosovo. Daily capacity of processing of concentrated sulphuric acid was 11,919 L/day. Due to the insulating layer damage, sulphate solutions have penetrated in the concrete layer and have created cracks, and in some places even degradation of the concrete. This degradation of concrete structures has also caused corrosion of steel rebar. Corrosion of steel bars negatively impacts their performance respectively in their mechanical properties. In the damaged areas penetration depths of acid impact are determined, by measuring the pH value. Mechanical properties, and corrosion rate of steel rebar based on the change of mass, were researched in laboratory conditions. Experiments were performed in solutions that simulate conditions in the facility immersing steel bars samples in solutions with pH values, 5,6,10. The simulated pore solution (SPS) with pH = 12.5, contain NaOH, KOH and Ca(OH)_2 and represents the composition of undamaged concrete. While other solutions, with pH: 5, 6 and 10 are prepared adding H_2SO_4 in SPS solution.