Heah Cheng Yong
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Preferred name
Heah Cheng Yong
Official Name
Heah, Cheng Yong
Alternative Name
Yong, Heah Cheng
Yong, H. C.
Heah, Cheng Yong
Heah, C. Y.
Cheng-Yong, Heah
Cheng Yong, Heah
Main Affiliation
Scopus Author ID
54402789500
Researcher ID
S-7139-2019

Research Output

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  • Publication
    Turning waste into strength enhancing geopolymer composites with Oil Palm Frond Fibers (OPF)
    ( 2024-10)
    Ng Hui-Teng
    ;
    Liew Yun Ming
    ;
    Heah Cheng Yong
    ;
    Tan Soo Jin
    ;
    Muhammad Aqil Asyraf Bin Mohd Roslan
    ;
    Siti Khadijah Binti Zulkepli
    ;
    Tan You How
    ;
    Ng Yong-Sing
    Geopolymers are alternatives to ordinary Portland cement as construction materials. The increasing demand for sustainable construction materials has driven the utilization of industrial by-products and agricultural waste. The disposal of oil palm frond (OPF) biomass as waste in landfills poses significant environmental challenges, necessitating effective recycling strategies. This study examines the incorporation and feasibility of OPF as a reinforcing fiber in fly ash geopolymer composites, examining its impact on physical and mechanical properties. Various parameters were tested, including fiber content (10–20 wt.%), shapes (shredded and tubular), and lengths (1–3 cm). The geopolymer composites with 10 wt.% shredded oil palm frond and 1-cm tubular oil palm frond fibers enhance the compressive strength by 17% compared to the control sample without oil palm frond. The shredded oil palm frond was particularly effective, enhancing strength performance and achieving better dispersion within the geopolymer matrix. Conversely, increasing the fiber content and length generally resulted in diminished composite strength, attributed to the creation of a more porous structure and weaker fiber-matrix interactions. However, lower fiber additions were shown to decrease porosity and water absorption, highlighting the potential of optimized oil palm frond fiber content and form in improving the environmental and mechanical performance of geopolymer composites. These results support the viability of oil palm frond as a sustainable additive in geopolymers, contributing to waste reduction and material innovation in construction.
  • Publication
    Microstructural Analysis of Fly Ash-based Geopolymers with various Alkali Concentration
    ( 2019-08-14)
    Hui-Teng N.
    ;
    Heah Cheng Yong
    ;
    Yun-Ming L.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Yong-Sing N.
    In the present work, a comparative study on the effect of different concentration of sodium hydroxide (NaOH) on fly ash-based geopolymer was investigated. The geopolymer synthesis by mixing fly ash with alkali activator (a mixture of NaOH and sodium silicate) at solid/liquid ratio of 2.5. The NaOH were used 6M, 8M, 10M, 12M and 14M with constant sodium silicate/NaOH ratio of 2.5. The geopolymers were cured at room temperature (29°C) for 24 hours and 60°C in oven for another 24 hours. The testing and analysis of the fly ash-based geopolymers were performed after 28 days. The adequate Na+ ions and densified microstructure were observed at optimum 8M-NaOH-activated fly ash-based geopolymers.
  • Publication
    Discovering the roles of electrode distance and configuration in dye degradation and electricity generation in photocatalytic fuel cell integrated electro-Fenton process
    ( 2022-01-01)
    Thor S.H.
    ;
    Ho Li Ngee
    ;
    Ong Soon An
    ;
    Che Zulzikrami Azner Abidin
    ;
    Heah Cheng Yong
    ;
    Nordin N.
    ;
    Ong Y.P.
    ;
    Yap K.L.
    Photocatalytic fuel cell (PFC) integrated electro-Fenton (EF) system (PFC-EF system) was considered as an eco-friendly approach for dye degradation and electricity generation simultaneously. The modification on configuration of PFC-EF system was aimed to improve the dye degradation and power output. Effect of electrode distance on the efficiency of PFC-EF system was investigated as it was a crucial factor in the mass transfer of ions in PFC-EF system. Closer electrode distance reduced the resistance flow of ions and enhanced the mass transfer of ions between the electrodes in both PFC and EF, eventually yielded higher concentration of reactive species for removal of dye. Four different electrode configurations by varying the number of cathodes in PFC and EF were investigated to discover the most efficient operating configuration for this PFC-EF system. The dye decolourization rate was evaluated and compared by using pseudo-first order and second order in both PFC and EF system, respectively. Results revealed that single cathode PFC-EF system was the most effective configuration in dye degradation while double cathodes PFC-EF system was the optimal configuration to be used for power output.
  • Publication
    A sustainable photocatalytic fuel cell integrated photo-electro-Fenton hybrid system using KOH activated carbon felt cathodes for enhanced Amaranth degradation and electricity generation
    ( 2022-07-01)
    Thor S.H.
    ;
    Ho Li Ngee
    ;
    Ong Soon An
    ;
    Che Zulzikrami Azner Abidin
    ;
    Heah Cheng Yong
    ;
    Ong Y.P.
    ;
    Yap K.L.
    Photo-electro-Fenton (PEF) process was integrated with photocatalytic fuel cell (PFC) through the connection of electrodes and the cathodes were responsible for the acceptance of electrons. In this study, potassium hydroxide (KOH) was used to activate the carbon felt (CF) to improve the oxygen reduction reaction reactivity on cathodes for effective PFC integrated PEF hybrid system (PFC-PEF system) in Amaranth removal and electricity generation simultaneously. The results revealed that KOH activated CF cathodes had improved the electro-generation of hydrogen peroxide in both PFC and PEF and contributed to decolourisation efficiencies of 99.25% (PFC) and 96.10% (PEF). The maximum power density (4.218 μW cm−2) achieved by KOH activated CF cathode was 22% higher than that of pristine CF. The results revealed that air flow rate of 1000 mL min−1 favoured the generation of more reactive species for effective Amaranth degradation under the dissolved oxygen enrichment condition. The highest decolourisation rates were respectively achieved in PFC (0.5965 h−1) and PEF (0.2919 L mg−1 h−1) at air flow rate of 1000 mL min−1.
  • Publication
    Mechanical Properties and Thermal Conductivity of Lightweight Foamed Geopolymer Concretes
    ( 2019-08-14)
    Fatimah Azzahran Abdullah S.
    ;
    Yun-Ming L.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Heah Cheng Yong
    ;
    Zulkifly K.
    Foamed geopolymer concretes have a better performance in the thermal insulation properties compared to normal geopolymer concretes. In this research, lightweight aggregate geopolymer concretes was incorporated with different percentage of foaming agents (hydrogen peroxide). Compressive strength and thermal conductivity were measured. From results obtained, increased H2O2 contents will decrease the strength of lightweight foamed geopolymer concretes. Lightweight aggregate foamed geopolymer concretes (LWAFGC) with foaming agent content of 0.2wt.% obtained the highest strength of 19.601 MPa. Furthermore, Increased of H2O2 contents also will decrease the thermal conductivity of lightweight foamed geopolymer concretes. Lightweight foamed geopolymer concretes with 2wt.% H2O2 gave the good thermal insulating behavior when the thermal conductivity value recorded the lowest value compare to other wt.% of H2O2 content. The thermal conductivity value of lightweight foamed geopolymer concretes with 2wt.% of H2O2 was 0.072 W/m. K while, the thermal conductivity of other mixtures ranged between 0.077 W/m. K to 0.087 W/m. K., respectively.
  • Publication
    Enhanced Electrical Properties of Graphite-Doped Titanium Dioxide Thin Films via Sol-Gel Method
    (Universiti Malaysia Perlis, 2025-06)
    Foo Kai Loong
    ;
    Tan Soo Jin
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    Graphite-doped titanium dioxide (Gr-TiO₂) thin films were synthesized via the sol-gel method to enhance the electrical properties of TiO₂ for advanced electronic and biosensor applications. The study focuses on optimizing the drying temperatures and graphite doping levels to achieve improved film crystallinity, morphology, and conductivity. Thin films were deposited using spin-coating and analyzed through scanning electron microscopy (SEM), high-power microscopy (HPM), and current-voltage (I-V) measurements. Results indicate that increasing drying temperature enhances grain coalescence and reduces porosity, leading to improved electrical conductivity. Graphite doping effectively narrows the bandgap and introduces additional charge carriers. These findings demonstrate the potential of Gr-TiO₂ thin films for applications in photovoltaics, sensors, and other optoelectronic devices.
  • Publication
    Evaluation of flexural properties and characterisation of 10-mm thin geopolymer based on fly ash and ladle furnace slag
    ( 2021)
    Ng Yong-Sing
    ;
    Liew Yun Ming
    ;
    Heah Cheng Yong
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Lynette Wei Ling Chan
    ;
    Ng Hui-Teng
    ;
    Ong Shee-Ween
    ;
    Ooi Wan-En
    ;
    Hang Yong-Jie
    The formulation and flexural properties of thin fly ash geopolymers with thickness of merely 10 mm and replacement of ladle furnace slag to fly ash in thin geopolymer were presented. The formulation was discussed in terms of NaOH molarity, solid aluminosilicates-to-liquid alkali activator (S/L) mass ratio, and alkali activator (Na2SiO3/NaOH) mass ratio. Thin fly ash geopolymers with flexural strength and Young's modulus of 6.2 MPa and 0.14 GPa, respectively, were obtained by using 12 M NaOH, S/L ratio of 2.5 and Na2SiO3/NaOH ratio of 4.0. A high Na2SiO3/NaOH ratio was implemented for thin geopolymer synthesis to produce a more viscous slurry which helped to retain the shape of a thin geopolymer. The incorporation of ladle furnace slag up to 40 wt.% reported an increment of 26% in flexural strength up to 7.8 MPa as compared to pure fly ash geopolymers and the stiffness was increased to 0.19 GPa. Denser microstructure with improved compactness was observed as the ladle furnace slag acted as the filler. New crystalline phases of calcium silicate hydrate (C–S–H) were formed and coexisted with the geopolymer matrix, which consequently enhanced the flexural strength of thin fly ash geopolymer. This proved that the ladle furnace slag has the potential to be utilised in geopolymer synthesis and will enhance the flexural properties of thin geopolymers. The flexural performance of thin geopolymers in this study was considerably good as the thin geopolymers exhibited comparatively similar flexural strengths, but a higher strength/thickness ratio as compared to geopolymers with thickness greater than 40 mm.
      1  17
  • Publication
    Silica bonding reaction on fly ash based geopolymer repair material system with incorporation of various concrete substrates
    ( 2022)
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ikmal Hakem A. Aziz
    ;
    Warid Wazien Ahmad Zailani
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Heah Cheng Yong
    ;
    Andrei Victor Sandu
    ;
    Loke Siu Peng
    This paper presents an experimental investigation on the mechanical properties and microstructure of geopolymer repair materials mixed using fly ash (FA) and concrete substrates. An optimal combination of FA and concrete substrate was determined using the compressive test of geopolymer mortar mixed with various concrete substrate classes. It was found that the contribution of (C35/45) concrete substrates with the FA geopolymer mortar increases the 28-day bonding strength by 25.74 MPa. The microstructure analysis of the samples using scanning electron microscopy showed the denser structure owing to the availability of high calcium and iron elements distribution. These metal cations (Ca2+ and Fe3+) are available at OPC concrete substrate as a result from the hydration process reacted with alumina-silica sources of FA and formed calcium aluminate silicate hydrate (C-A-S-H) gels and Fe-bonding linkages
      2  9
  • 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
  • Publication
    Effect of silica fume and alumina addition on the mechanical and microstructure of fly ash geopolymer concrete
    ( 2021)
    Fong Sue Min
    ;
    Heah Cheng Yong
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Hasniyati Md Razi
    ;
    Foo Wah Low
    ;
    Ng Hui-Teng
    ;
    Ng Yong-Sing
    This paper discussed the effect of the addition of silica fume (2 wt.% and 4 wt.%) and alumina (2 wt.% and 4 wt.%) on the properties of fly ash geopolymer concrete. The fly ash geopolymer concrete achieved the highest 28-day compressive strength with 2 wt.% of silica fume (39 MPa) and 4 wt.% of alumina (41 MPa). The addition of 2 wt.% of silica fume increased the compressive strength by 105% with respect to the reference geopolymer (without additive). On the other hand, the compressive strength surged by 115% with 4 wt.% of alumina compared to the reference geopolymer. The addition of additives improved the compactness of the geopolymer matrix according to the morphology analysis.
      1  9