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
Now showing 1 - 3 of 3
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Publication

Preparation of fly Ash-Ladle furnace slag blended geopolymer foam via Pre-Foaming method with polyoxyethylene alkyether sulphate incorporation

2022 , Ng Hui-Teng , Heah Cheng Yong , Liew Yun Ming , Mohd. Mustafa Al Bakri Abdullah , Catleya Rojviriya , Hasniyati Md Razi , Sebastian Garus , Marcin Nabiałek , Wojciech Sochacki , Ilham Mukriz Zainal Abidin , Ng Yong-Sing , Andrei Victor Sandu , Agata Śliwa

This paper uses polyoxyethylene alkyether sulphate (PAS) to form foam via pre-foaming method, which is then incorporated into geopolymer based on fly ash and ladle furnace slag. In the literature, only PAS-geopolymer foams made with single precursor were studied. Therefore, the performance of fly ash-slag blended geopolymer with and without PAS foam was investigated at 29–1000 °C. Unfoamed geopolymer (G-0) was prepared by a combination of sodium alkali, fly ash and slag. The PAS foam-to-paste ratio was set at 1.0 and 2.0 to prepare geopolymer foam (G-1 and G-2). Foamed geopolymer showed decreased compressive strength (25.1–32.0 MPa for G-1 and 21.5–36.2 MPa for G-2) compared to G-0 (36.9–43.1 MPa) at 29–1000 °C. Nevertheless, when compared to unheated samples, heated G-0 lost compressive strength by 8.7% up to 1000 °C, while the foamed geopolymer gained compressive strength by 68.5% up to 1000 °C. The thermal stability of foamed geopolymer was greatly improved due to the increased porosity, lower thermal conductivity, and incompact microstructure, which helped to reduce pressure during moisture evaporation and resulted in lessened deterioration.

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Publication

Formulation, mechanical properties and phase analysis of fly ash geopolymer with ladle furnace slag replacement

2021 , Ng Hui-Teng , Heah Cheng Yong , Kong Ern Hun , Mohd. Mustafa Al Bakri Abdullah , Liew Yun Ming , Hasniyati Md Razi , Ng Yong-Sing

This paper presents the formulation of fly ash (FA) geopolymer and the incorporation of ladle furnace slag (LFS) as a replacement to FA in geopolymer formation. The formulation of the LFS replacement was set at 10–40 wt.%. The geopolymer was formed by mixing FA and LFS with a sodium-based alkali activator. The FA geopolymer had a compressive strength of 38.9 MPa with the optimum formulation of 8 M NaOH concentration, AS/AA ratio of 3, and AA ratio of 1.5. The compressive strength was affected more significantly by the amorphous content. The most influential factors affecting the properties of FA geopolymer were: AS/AA ratio > AA ratio > NaOH concentration. Replacing LFS led to very little (4.1%) increment in the compressive strength. The LFS had little contribution in supplying Si, Al and Ca for the formation of the N-A-S-H and C-A-S-H network. But LFS acted as a filler and improved the compactness of the FA geopolymer. The mechanical performance of FA/LFS geopolymer was not governed by the amorphous content like the FA geopolymer, as LFS addition contributed to increasing crystalline content. New crystalline phases of calcite and CSH due to the addition of LFS helped to retain the compressive strength of FA geopolymer. Nevertheless, the outcome of the study proved that LFS can be blended with FA to produce geopolymers without severe deterioration in mechanical strength. LFS can be potentially added in geopolymers as filler to produce geopolymer mortar.

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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.

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