A study of Ni–Ti shape memory alloy-steel fiber hybrid reinforcement in GGBS mortar for corrosion resistance

• Published in: Mechanics of time-dependent materials 2024-12, Vol.28 (4), p.2511-2530
• Main Authors: Thomas, Geethu Elsa, Sajith, A. S., Indira, P. V.
• Format: Article
• Language: English
• Subjects: Acid resistance; Aging (metallurgy); Characterization and Evaluation of Materials; Chloride resistance; Classical Mechanics; Compressive strength; Corrosion resistance; Corrosion resistant alloys; Corrosion resistant steels; Corrosion tests; Durability; Engineering; Fiber reinforced concretes; Fiber volume fraction; Flexural strength; Fourier transforms; GGBS; Infrared analysis; Infrared spectroscopy; Mechanical properties; Modulus of elasticity; Mortars (material); Polymer Sciences; Reinforcing steels; Resistance factors; Shape memory alloys; Solid Mechanics; Spectroscopic analysis; Spectrum analysis; Tensile strength; Water resistance
• ISSN: 1385-2000; 1573-2738
• DOI: 10.1007/s11043-023-09651-7

Fiber-reinforced concrete (FRC) has become popular due to its ability to enhance mechanical properties. However, FRC has limitations regarding aging, durability, and corrosion. A superelastic shape memory alloy (SMA) is an alternate reinforcement material that can enhance a structure’s lifespan. This study evaluates the mechanical, durability, and corrosion resistance characteristics of hybrid combinations of nickel–titanium (Ni–Ti) SMA fibers and steel fibers in mortar. Three hybrid fiber combinations (GH1-75% steel fiber+ 25% SMA fiber, GH2-50% steel fiber+50% SMA fiber, and GH3-25% steel fiber+75% SMA fiber) were investigated in this study, with a total of 0.50% fiber volume ratio. To enhance the durability properties of the mortar, ground granulated blast furnace slag (GGBS) was used as a partial replacement for cement. The engineering properties of these hybrid fiber combinations in GGBS mortar were evaluated through compressive strength, flexural strength, and split tensile strength. Durability features were assessed based on acid, sulfate, chloride, and marine water resistance. The results showed that the hybrid mix with a greater quantity of steel fiber (GH1) had superior mechanical properties due to the steel fiber’s greater modulus of elasticity. However, when exposed to an aggressive environment, the hybrid combination with a greater quantity of Ni–Ti SMA fibers (GH3) in mortar showed higher durability and corrosion resistance. The samples from durability studies were further tested for Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, X-Ray Diffraction Analysis, and Fourier Transform Infrared Spectroscopy. The microstructural studies revealed the factors contributing to the enhanced durability and corrosion resistance of Ni–Ti SMA fibers in the composite.