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Nur Ain Jaya
Preferred name
Nur Ain Jaya
Official Name
Nur Ain, Jaya
Alternative Name
Jaya, N. A.
Ain Jaya, Nur
Jaya, Nur Ain
Nur, Ain Jaya
Main Affiliation
Scopus Author ID
56354805400
Researcher ID
AAW-9244-2021
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1 - 3 of 3
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PublicationEffect of anisotropic pores on the material properties of metakaolin geopolymer composites incorporated with corrugated fiberboard and rubber( 2021)
;Low Foo Wah ;Ooi Wan-En ;Ilham Mukriz Zainal AbidinNoorhazleena AzamanThis paper compares the compressive strength and thermal conductivity of metakaolin geopolymer (MKG) incorporated with anisotropic and isotropic pores. MKG was prepared by activation with sodium hydroxide and sodium silicate. Corrugated fiberboard and rubber were included to create anisotropy of pores, and they were added in 3, 5, and 7 layers. Hydrogen peroxide and surfactant were added to generate isotropic pores. For geopolymer with corrugated fiberboard (MKG-C) and rubber (MKG-R), compressive test and thermal conductivity measurement were performed in perpendicular and parallel direction to the flat surface of fiberboard and rubber. The result showed that MKG-C and MKG-R exhibited mechanical and insulation anisotropically. The highest compressive strength was achieved in the parallel loading direction while the lowest thermal conductivity was attained in the perpendicular direction. MKG-C possessed better compressive strength of 26.9 MPa loaded in the parallel direction. The compressive strength performance of MKG-C was greater than MKG-R because of the fibrous-like structure, which further contributes to the strength. The thermal conductivity was low (0.15–0.20 W/mK) for both MKG-C and MKG-R. The anisotropy of pores led to high strength retention and improvement of thermal insulating properties. These properties were contrary to geopolymer with isotropic pores (MKG-F), which have excellent thermal insulating properties but low compressive strength to be eligible for structural applications. -
PublicationCold-pressed fly ash geopolymers: effect of formulation on mechanical and morphological characteristics( 2021)
;Ong Shee-Ween ;Lynette Wei Ling Chan ;Ooi Wan-En ;Ng Yong-SingThis research uses low alkali activator content and cold pressing technique for fly ash-based geopolymers formation under room temperature condition. The geopolymers were prepared using four different parameters: fly ash/alkali activator ratio, sodium hydroxide concentration, sodium silicate/sodium hydroxide ratio and pressing force. The results indicated that the compressive strength (114.2 MPa) and flexural strength (29.9 MPa) of geopolymers maximised at a fly ash/alkali activator ratio of 5.5, a 14 M sodium hydroxide concentration, a sodium silicate/sodium hydroxide ratio of 1.5 and a pressing force of 5 tons (pressing stress of 100.0 MPa and 155.7 MPa for compressive and flexural samples, respectively). The degree of reaction (40.1%) enhanced the structure compactness with minimum porosity. The improved mechanical properties confirmed that a high strength pressed geopolymer could be formed at low alkali activator content without the aid of temperature.9 21 -
PublicationCorrelation between pore structure, compressive strength and thermal conductivity of porous metakaolin geopolymerThis paper investigates the effect of mixing parameters (that are, alkali concentration, AA ratio, and MK/ AA ratio) on the thermal conductivity of metakaolin geopolymers. The combination effect of foaming agent (H2O2) and surfactant (Tween 80) on the physical properties, compressive strength, and pore characteristic was also elucidated. Results showed that metakaolin geopolymer with maximum compressive strength of 33 MPa, bulk density of 1680 kg/m3 , porosity of 18% and thermal conductivity of 0.40 W/mK were achieved with alkali concentration of 10 M, AA ratio of 1.0 and MK/AA ratio of 0.8. Gradation analysis demonstrated that AA ratio was the strength determining factor. Whilst, thermal conductivity was dependent on the MK/AA ratio. Adding H2O2 and surfactant produced geopolymer foam with acceptable compressive strength (0.4–6 MPa). The geopolymer foam had bulk density of 471–1212 kg/m3 , porosity of 36–86% and thermal conductivity of 0.11–0.30 W/mK. Pore structure, size, and distribution were governed by H2O2 and surfactant dosages that have a great impact on the compressive strength. Narrower pore distribution and smaller pore diameter were achieved when both foaming agent and surfactant were used instead of foaming agent alone. The pore size and distribution varied to a greater extent with varying H2O2 contents. Surfactant illustrated distinct pore stabilizing effect at low H2O2 (<0.75 wt%) which diminished at high H2O2 content. In terms of thermal conductivity, even with increasing porosity at high H2O2 and surfactant content, the thermal conductivity did not show substantial reduction due to the interconnected pores as a result of pore coalescence
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