PSI - Issue 66

Ram Lal Riyar et al. / Procedia Structural Integrity 66 (2024) 181–194 Ram Lal Riyar et. al./ Structural Integrity Procedia 00 (2025) 000–000

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was observed that, when corrosion is 5%, the peak load is lowered by 11.5%; when the corrosion is 10%, it is reduced by 24.9%; and when it is 15%, it is reduced by 27.14%. The structural integrity and functionality of materials and constructions are significantly impacted by the increase in equivalent fracture length brought on by corrosion. The ability of components to bear loads may be reduced by the growth of cracks, which can also affect their stiffness and strength and make them more susceptible to catastrophic collapse. The crack length is calculated at different points of loading conditions using Equation (1). The load increases up to the peak load and after the peak load, the load starts to decrease. The variation of crack length with respect to load has been plotted in Figure 11(a). It has been observed that the crack length v/s load relationship has a steeper slope, which indicates that the fracture will spread more quickly as the load rises when the corrosion increases. a c = ଶ గ ௛ arctan ට ௕ா ଷଶ ஼ெை஽௖ . ଺௉௠௔௫ - 0.1135 (1) In this context, the specimen height is represented by h, the breadth of the specimen is denoted as b, E represents the concrete elastic modulus, the maximum load is indicated as Pmax, and the maximum CMOD at that maximum load is denoted as CMODc.

(a) (c) Fig. 11. Variations of (a) Load, (b) Fracture toughness, and (c)Fracture energy with the same crack length. (b)

Corrosion has a negative impact on a material's fracture toughness, making it more prone to brittle fracture. Chemical processes that lead to corrosion change a material's microstructure and mechanical characteristics, particularly its fracture toughness. Numerous factors, including corrosion, which weaken fracture toughness are as follows:  Deterioration of the substance: Corrosion may lead to the loss of the substance and a reduction in its overall toughness and strength. Oxides and salts, which are results of corrosion, may weaken a material, introduce defects, and reduce its resistance to fracture propagation.  Stress concentration: Corrosion may form small, concentrated areas of weaker material, such as pits or fissures, which act as stress concentrators. These stress-concentration zones could promote the growth of fractures and reduce the material's resistance to fracture.  Embrittlement: Some types of corrosion, including hydrogen embrittlement, may occur in the presence of hydrogen ions or gas. The hydrogen absorbed by the material may cause embrittlement, increasing its brittle fracture susceptibility and lowering its fracture toughness.  Crack propagation: Corrosion may hasten the development of cracks in certain materials. By-products of corrosion and defects may operate as favored crack propagation channels, hastening the production of cracks and decreasing fracture toughness. In accordance with the ASTM standard E399-90, the fracture toughness can be computed using Equation (2). From Figure 11(b), It was observed that the material offered resistance against the applied force, and as a result, the structural fracture toughness improved as the crack length grew up to the peak load. The fracture toughness declines after