Now showing 1 - 3 of 3
  • Publication
    Recent developments in steelmaking industry and potential alkali activated based steel waste: A comprehensive review
    ( 2022)
    Ikmal Hakem Aziz
    ;
    ; ; ;
    Long Yuan Li
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    ;
    Ovidiu Nemes
    ;
    Shaik Numan Mahdi
    The steel industry is responsible for one-third of all global industrial CO2 emissions, putting pressure on the industry to shift forward towards more environmentally friendly production methods. The metallurgical industry is under enormous pressure to reduce CO2 emissions as a result of growing environmental concerns about global warming. The reduction in CO2 emissions is normally fulfilled by recycling steel waste into alkali-activated cement. Numerous types of steel waste have been produced via three main production routes, including blast furnace, electric arc furnace, and basic oxygen furnace. To date, all of the steel waste has been incorporated into alkali activation system to enhance the properties. This review focuses on the current developments over the last ten years in the steelmaking industry. This work also summarizes the utilization of steel waste for improving cement properties through an alkali activation system. Finally, this work presents some future research opportunities with regard to the potential of steel waste to be utilized as an alkali-activated material.
  • Publication
    Improvements of flexural properties and thermal performance in thin geopolymer based on fly ash and ladle furnace slag using borax decahydrates
    ( 2022)
    Ng Yong-Sing
    ;
    ; ; ;
    Phakkhananan Pakawanit
    ;
    Petrica Vizureanu
    ;
    Mohd Suhaimi Khalid
    ;
    Ng Hui-Teng
    ;
    Hang Yong-Jie
    ;
    Marcin Nabiałek
    ;
    Paweł Pietrusiewicz
    ;
    Sebastian Garus
    ;
    Wojciech Sochacki
    ;
    Agata Åšliwa
    This paper elucidates the influence of borax decahydrate addition on the flexural and thermal properties of 10 mm thin fly ash/ladle furnace slag (FAS) geopolymers. The borax decahydrate (2, 4, 6, and 8 wt.%) was incorporated to produce FAB geopolymers. Heat treatment was applied with temperature ranges of 300 °C, 600 °C, 900 °C, 1000 °C and 1100 °C. Unexposed FAB geopolymers experienced a drop in strength due to a looser matrix with higher porosity. However, borax decahydrate inclusion significantly enhanced the flexural performance of thin geopolymers after heating. FAB2 and FAB8 geopolymers reported higher flexural strength of 26.5 MPa and 47.8 MPa, respectively, at 1000 °C as compared to FAS geopolymers (24.1 MPa at 1100 °C). The molten B2O3 provided an adhesive medium to assemble the aluminosilicates, improving the interparticle connectivity which led to a drastic strength increment. Moreover, the borax addition reduced the glass transition temperature, forming more refractory crystalline phases at lower temperatures. This induced a significant strength increment in FAB geopolymers with a factor of 3.6 for FAB8 at 900 °C, and 4.0 factor for FAB2 at 1000 °C, respectively. Comparatively, FAS geopolymers only achieved 3.1 factor in strength increment at 1100 °C. This proved that borax decahydrate could be utilized in the high strength development of thin geopolymers.
  • Publication
    Thermal insulation and mechanical properties in the presence of glas bubble in fly ash geopolymer paste
    ( 2021)
    Noor Fifinatasha Shahedan
    ;
    ; ; ; ;
    Ikmal Hakem A Aziz
    ;
    Aeslina Abdul Kadir
    ;
    Andrei Victor Sandu
    ;
    The density, compressive strength, and thermal insulation properties of fly ash geopolymer paste are reported. Novel insulation material of glass bubble was used as a replacement of fly ash binder to significantly enhance the mechanical and thermal properties compared to the geopolymer paste. The results showed that the density and compressive strength of 50% glass bubble was 1.45 g/ ely, meeting the standard requirement for structural concrete. Meanwhile, the compatibility of 50% glass bubbles tested showed that the thermal conductivity (0.898 W/mK), specific heat (2.141 MJ/m3 K), and thermal diffusivity(0.572 mm2/s) in meeting the same requirement. The improvement of thermal insulation properties revealed the potential use of glass bubbles as an insulation material in construction material
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