Now showing 1 - 2 of 2
  • Publication
    Phase transformation of Kaolin-ground granulated blast furnace slag from geopolymerization to sintering process
    ( 2021-03-01) ; ; ;
    Hasmaliza M.
    ;
    ;
    Aziz I.H.A.
    ;
    Jeż B.
    ;
    Nabiałek M.
    The main objective of this research was to investigate the influence of curing temperature on the phase transformation, mechanical properties, and microstructure of the as-cured and sintered kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The curing temperature was varied, giving four different conditions; namely: Room temperature, 40, 60, and 80â—¦ C. The kaolin-GGBS geopolymer was prepared, with a mixture of NaOH (8 M) and sodium silicate. The samples were cured for 14 days and sintered afterwards using the same sintering profile for all of the samples. The sintered kaolin-GGBS geopolymer that underwent the curing process at the temperature of 60â—¦ C featured the highest strength value: 8.90 MPa, and a densified microstructure, compared with the other samples. The contribution of the Na2 O in the geopolymerization process was as a self-fluxing agent for the production of the geopolymer ceramic at low temperatures.
      2
  • Publication
    Influences of SiO2, Al2O3, CaO and MgO in phase transformation of sintered kaolin-ground granulated blast furnace slag geopolymer
    ( 2020-01-01)
    Jamil N.H.
    ;
    ; ;
    Mohamad H.
    ;
    ;
    Chaiprapa J.
    Kaolin has an excellent structure formed via a wide range of firing temperature. The correlation between the mineralogy and reactivity of individual elements is extremely complex in a sintered geopolymer material. The main objective of this work is to elucidate the influence of the chemical composition of the raw materials used post-sintering on the kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The samples were cured at room temperature for 5 days before being sintered. The ratio of solid-to-liquid were 1:1, 1.5:1, and 2:1. The addition of the GGBS to the kaolin geopolymer slurry did not only hasten the hardening process during geopolymerization, the presence of SiO2, Al2O3, CaO, and MgO in GGBS had accelerated the formation of nepheline, gehlenite, akermanite, and albite phase after sintering based on the result from x-ray diffraction and fourier-transform infrared spectroscopy On top of the phase transformation, a high ratio of solid-to-liquid (SL 2) had improved the pore distribution from irregular size to well defined formation and increased the densification of the sintered materials. Elemental distribution from micro-XRF investigation prove the high concentration of Ca in localized area and uniformly distribution of Si aligned with the phase of akermanite in SL 2. The main chemical composition of kaolin and GGBS which are SiO2, Al2O3, CaO and MgO had contributed in phase transformation of sintered kaolin-GGBS geopolymer.
      1  40