Now showing 1 - 2 of 2
  • Publication
    Ladle furnace slag replacement on the flexural strength of thin fly ash geopolymer
    ( 2020)
    Ng YONG-SING
    ;
    ; ;
    Ng HUI-TENG
    ;
    Ridho BAYUAJI
    This article reports the investigation on the effect of ladle furnace slag replacement on the flexural strength of thin fly ash-based geopolymer. The thin fly ash/slag geopolymers were prepared with the replacement of various percentages of ladle furnace slag (0%, 10%, 20%, 30% and 40%) into fly ash geopolymers with dimension of 160 mm × 40 mm × 10 mm. The thin geopolymerwas synthesised using 12M sodium hydroxide (NaOH) solution with solid-to-liquid (S/L) ratio of 2.5 and Na2SiO3 /NaOH ratio of 4.0. The curing temperature and time of samples were 60°C and 6 hours respectively. The mechanical properties of thin geopolymers was revealed using flexural test after 28 days. Several characterisation tools have been used including Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) to correlate the flexural properties with the microstructure and phases of fly ash/slag geopolymers. Results obtained reported that a positive effect on flexural strength was observed with the increasing amount of slag. The thin fly ash geopolymers replaced with 40% of ladle furnace slag showed the highest flexural strength of 7.8 MPa. The rich CaO content in ladle furnace slag boosted the C-S-H gels formation which increased the flexural strength of thin geopolymers.
  • Publication
    Elevated-Temperature performance, combustibility and fire propagation index of Fly Ash-Metakaolin blend geopolymers with addition of Monoaluminium Phosphate (MAP) and Aluminum Dihydrogen Triphosphate (ATP)
    ( 2021)
    Khairunnisa Zulkifly
    ;
    ; ;
    Ridho Bayuaji
    ;
    ;
    Shamsul Bin Ahmad
    ;
    Tomasz Stachowiak
    ;
    Janusz Szmidla
    ;
    Joanna Gondro
    ;
    Bartłomiej Jeż
    ;
    Mohd Suhaimi Bin Khalid
    ;
    Sebastian Garus
    ;
    Ong Shee-Ween
    ;
    Ooi Wan-En
    ;
    Ng Hui-Teng
    Thermal performance, combustibility, and fire propagation of fly ash-metakaolin (FA-MK) blended geopolymer with the addition of aluminum triphosphate, ATP (Al(H2PO4)3), and monoaluminium phosphate, MAP (AlPO4) were evaluated in this paper. To prepare the geopolymer mix, fly ash and metakaolin with a ratio of 1:1 were added with ATP and MAP in a range of 0–3% by weight. The fire/heat resistance was evaluated by comparing the residual compressive strengths after the elevated temperature exposure. Besides, combustibility and fire propagation tests were conducted to examine the thermal performance and the applicability of the geopolymers as passive fire protection. Experimental results revealed that the blended geopolymers with 1 wt.% of ATP and MAP exhibited higher compressive strength and denser geopolymer matrix than control geopolymers. The effect of ATP and MAP addition was more obvious in unheated geopolymer and little improvement was observed for geopolymer subjected to elevated temperature. ATP and MAP at 3 wt.% did not help in enhancing the elevated-temperature performance of blended geopolymers. Even so, all blended geopolymers, regardless of the addition of ATP and MAP, were regarded as the noncombustible materials with negligible (0–0.1) fire propagation index.