Gaussian descriptions of corrosion initiation in steel bars of fly ash concrete elements

Abstract

The process of non-uniform chloride ingress into fly ash reinforced concrete (RC) elements due to the presence of steel bars influences the spatio-temporal variations of chloride ions to a significant level. This study explores the process of non-uniform chloride ingress in fly ash RC beams adopting a numerical formulation of the associated field equations with due consideration to the presence and geometry of both rebars and stirrups. The evaluated corrosion evolution profiles were categorised into type-I and type-II with the former being identified as having higher potential to cause severe structural deterioration. Further, a Gaussian function is proposed to mathematically describe the evolution and dynamics of corrosion initiation along the perimeters of stirrups and rebars including steel surfaces at stirrup-rebar intersections. Qualitative comparisons of the effects of various parameters on corrosion-induced damages show that the size, orientation and location of the stirrups and rebars have a major impact on corrosion-induced damages.

Keywords:

• Chloride ingress
• fly ash concrete
• reinforcement
• corrosion
• finite element method
• Gaussian function