Biogenic corrosion on ribbed reinforcing steel bars with different bending angles in sewage systems

• Biogenic corrosion on ribbed rebars with different bending angle was investigated.
• Sulfuric acid was used in three different molarity (0.5 M, 1 M and 1.5 M).
• The cross section of 12 mm straight rebars was decreased between 2.8% and 5.5% in 1.5 M acidic media.
• Rebar diameter and bent angle increased H2 evolution and corrosion rate reduced.
• The steel bar that exposed to 1.5 M acidic media presented a more serious corrosion on the surface.

Reinforcement steel rebar corrosion leads to a deterioration of the bond between the concrete and the steel bars. The serviceability and ultimate strength of concrete elements within reinforced structures are accordingly affected. Many studies have been done on the different types of steel bar corrosion. However, very few studies have investigated the effects of restrictions on the degradation of steel when exposed to sulfuric acid corrosion on bent steel rebars. In the present paper, investigations were carried out to study the corrosion behavior of unprotected low-carbon ribbed reinforcing steel exposed to different concentrations of H2SO4 solutions. The ribbed steel bars were of size Ø12, Ø14, Ø16 and bent at angles of angles of 0°, 45°, 90° and 135°. The weight loss method was used for the estimation of the corrosion. The results show that the corrosion rate and cross-section loss of steel bars increases with increasing acid concentration from 0.5 M to 1.5 M. On the other hand, corrosion deterioration was decreased with an increased bending angle.