Liew Yun Ming
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Preferred name
Liew Yun Ming
Official Name
Liew Yun Ming
Alternative Name
Yun-Ming, Liew
Liew, Y. M.
Yun Ming, Liew
Ming, Liew Yun
Liew, Yun Ming
Ming, L. Y.
Main Affiliation
Scopus Author ID
57204242778
Researcher ID
S-7164-2019

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  • Publication
    Thermo-mechanical behaviour of fly ash-ladle furnace slag blended geopolymer with incorporation of decahydrate borax
    ( 2022-05-09)
    Ng Hui Teng
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rojviriya C.
    ;
    Ken P.W.
    ;
    Ong Shee Ween
    ;
    Hang Yong Jie
    ;
    Ooi Wan En
    This paper elucidates the effect of adding decahydrate borax (1 and 2 wt%) on thermo-mechanical properties of fly ash-ladle furnace slag (FS) geopolymer at 29 °C – 1000 °C. Adding borax improved the compressive strength of unheated (40.5 MPa) and heat-treated (36.9 – 43.1 MPa) FS geopolymers by 8.4% and 21.2%, respectively. The higher crystallinity, incompact microstructure, and the presence of B-bonds and B-crystals contributed to the high-temperature resistance of FS-B geopolymer. The reduced sintering temperature by 75 °C due to addition of borax compared to FS geopolymer improved the thermal stability and structural integrity during high-temperature applications.
      1
  • Publication
    Thermo-mechanical behaviour of fly ash-ladle furnace slag blended geopolymer with incorporation of decahydrate borax
    ( 2022-05-09)
    Ng Hui Teng
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rojviriya C.
    ;
    Ken P.W.
    ;
    Ong Shee Ween
    ;
    Hang Yong Jie
    ;
    Ooi Wan En
    This paper elucidates the effect of adding decahydrate borax (1 and 2 wt%) on thermo-mechanical properties of fly ash-ladle furnace slag (FS) geopolymer at 29 °C – 1000 °C. Adding borax improved the compressive strength of unheated (40.5 MPa) and heat-treated (36.9 – 43.1 MPa) FS geopolymers by 8.4% and 21.2%, respectively. The higher crystallinity, incompact microstructure, and the presence of B-bonds and B-crystals contributed to the high-temperature resistance of FS-B geopolymer. The reduced sintering temperature by 75 °C due to addition of borax compared to FS geopolymer improved the thermal stability and structural integrity during high-temperature applications.
      2  4
  • Publication
    Towards greener one-part geopolymers through solid sodium activators modification
    ( 2022-12-10)
    Ooi Wan En
    ;
    Liew Yun Ming
    ;
    Heah Cheng Yong
    ;
    Ho Li Ngee
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Bin Khalid M.S.
    ;
    Foo Kai Loong
    ;
    Ong Shee Ween
    ;
    Pei Seng T.
    ;
    Hang Yong Jie
    ;
    Khairunnisa Zulkifly
    This paper investigates the influence of various solid activators and their mixing parameters on the physical, mechanical and microstructural characteristics of greener one-part geopolymers (OPG) based on high calcium fly ash. The high calcium fly ash that has rarely been explored was utilised to develop OPG in this study. The anhydrous sodium metasilicate (Na2SiO3) with negative environmental impact propelled the partial replacement of Na2SiO3 with sodium hydroxide (NaOH) and sodium carbonate (Na2CO3). Two sets of high calcium fly ash OPGs were developed: (1) the MH-OPG comprised Na2SiO3 and NaOH; (2) the MC-OPG comprised Na2SiO3 and Na2CO3. The optimal MH-OPG (73 MPa) and MC-OPG (75 MPa) exhibited superior compressive strength, higher than the minimal requirement (>28 MPa) of ASTM C150/C150M-18 for construction binder material. Various solid alkali activators triggered different reaction mechanisms, yielding distinctive reaction products that contributed to strength growth. The sodium calcium aluminosilicate hydrate ((N,C)-A-S-H) gel was developed in MH-OPG, whereas the sodium carbonate hydrate, sodium aluminosilicate hydrate (N-A-S-H) and calcium aluminosilicate hydrate (C-A-S-H) binding phases were developed in the MC-OPG. Although Na2CO3 reduced the water demand, improved the fluidity and setting time, the MC-OPG was more sensitive to the alteration of mixing compositions, suggesting a tougher performance control during field application than the MH-OPG. The total embodied carbon (EC) of MC-OPG was lowered by 15.4% compared to that of MH-OPG. The embodied carbon index (ECI) of MH-OPG and MC-OPG were 81.3% and 84.7% less than that of OPC products. This work suggests that substituting Na2SiO3 with NaOH or Na2CO3 effectively produced a greener construction material without compromising mechanical strength.
      1
  • Publication
    Towards greener one-part geopolymers through solid sodium activators modification
    ( 2022-12-10)
    Ooi Wan-En
    ;
    Liew Yun Ming
    ;
    Heah Cheng Yong
    ;
    Ho Li Ngee
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Bin Khalid M.S.
    ;
    Foo Kai Loong
    ;
    Ong Shee-Ween
    ;
    Pei Seng T.
    ;
    Hang Yong Jie
    ;
    Khairunnisa Zulkifly
    This paper investigates the influence of various solid activators and their mixing parameters on the physical, mechanical and microstructural characteristics of greener one-part geopolymers (OPG) based on high calcium fly ash. The high calcium fly ash that has rarely been explored was utilised to develop OPG in this study. The anhydrous sodium metasilicate (Na2SiO3) with negative environmental impact propelled the partial replacement of Na2SiO3 with sodium hydroxide (NaOH) and sodium carbonate (Na2CO3). Two sets of high calcium fly ash OPGs were developed: (1) the MH-OPG comprised Na2SiO3 and NaOH; (2) the MC-OPG comprised Na2SiO3 and Na2CO3. The optimal MH-OPG (73 MPa) and MC-OPG (75 MPa) exhibited superior compressive strength, higher than the minimal requirement (>28 MPa) of ASTM C150/C150M-18 for construction binder material. Various solid alkali activators triggered different reaction mechanisms, yielding distinctive reaction products that contributed to strength growth. The sodium calcium aluminosilicate hydrate ((N,C)-A-S-H) gel was developed in MH-OPG, whereas the sodium carbonate hydrate, sodium aluminosilicate hydrate (N-A-S-H) and calcium aluminosilicate hydrate (C-A-S-H) binding phases were developed in the MC-OPG. Although Na2CO3 reduced the water demand, improved the fluidity and setting time, the MC-OPG was more sensitive to the alteration of mixing compositions, suggesting a tougher performance control during field application than the MH-OPG. The total embodied carbon (EC) of MC-OPG was lowered by 15.4% compared to that of MH-OPG. The embodied carbon index (ECI) of MH-OPG and MC-OPG were 81.3% and 84.7% less than that of OPC products. This work suggests that substituting Na2SiO3 with NaOH or Na2CO3 effectively produced a greener construction material without compromising mechanical strength.
      1
  • Publication
    Comparison of thermal performance between fly ash geopolymer and fly ash-ladle furnace slag geopolymer
    ( 2022-06-01)
    Ng Hui Teng
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Pakawanit P.
    ;
    Bayuaji R.
    ;
    Ng Yong Sing
    ;
    Khairunnisa Zulkifly
    ;
    Ooi Wan En
    ;
    Hang Yong Jie
    ;
    Ong Shee Ween
    This paper compared the thermal stability between fly ash (FA) and fly ash-ladle furnace slag (FA-LS) geopolymers. FA-LS geopolymer was prepared by mixing FA and LS (FA:LS weight ratio of 80:20) with an alkali activator. Geopolymers were aged at room temperature for 28 days before being exposed to high temperatures (200 °C – 1000 °C). Unexposed FA and FA-LS geopolymers had a compressive strength of 38.9 MPa and 40.5 MPa, respectively. The FA and FA-LS geopolymers retained 61.6% and 91.3% compressive strength, respectively, when exposed to temperatures up to 1000 °C. FA-LS geopolymers experienced smaller variation in the density (2.6 – 5.5%) and pores (17.4 – 23.0%) compared to FA geopolymers (density and porosity of 2.9 – 25.2% and 19.0 – 30.0%, respectively). The formation of crystalline peaks, densification of matrix, pores and their connectivity, cracks and dimensional changes influenced the compressive strength of exposed geopolymers. FA-LS geopolymers could be potentially applied as heat-resistance material.
      1  5
  • Publication
    Comparison of thermal performance between fly ash geopolymer and fly ash-ladle furnace slag geopolymer
    ( 2022-06-01)
    Ng Hui Teng
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Pakawanit P.
    ;
    Bayuaji R.
    ;
    Ng Yong Sing
    ;
    Khairunnisa Zulkifly
    ;
    Ooi Wan En
    ;
    Hang Yong Jie
    ;
    Ong Shee Ween
    This paper compared the thermal stability between fly ash (FA) and fly ash-ladle furnace slag (FA-LS) geopolymers. FA-LS geopolymer was prepared by mixing FA and LS (FA:LS weight ratio of 80:20) with an alkali activator. Geopolymers were aged at room temperature for 28 days before being exposed to high temperatures (200 °C – 1000 °C). Unexposed FA and FA-LS geopolymers had a compressive strength of 38.9 MPa and 40.5 MPa, respectively. The FA and FA-LS geopolymers retained 61.6% and 91.3% compressive strength, respectively, when exposed to temperatures up to 1000 °C. FA-LS geopolymers experienced smaller variation in the density (2.6 – 5.5%) and pores (17.4 – 23.0%) compared to FA geopolymers (density and porosity of 2.9 – 25.2% and 19.0 – 30.0%, respectively). The formation of crystalline peaks, densification of matrix, pores and their connectivity, cracks and dimensional changes influenced the compressive strength of exposed geopolymers. FA-LS geopolymers could be potentially applied as heat-resistance material.
      1