Kamarudin Hussin, Brig. Jen. Datuk Prof. Dr.http://dspace.unimap.edu.my:80/xmlui/handle/123456789/137012024-03-29T10:16:33Z2024-03-29T10:16:33ZThe effects of various concentrations of NaOH on the inter-particle gelation of a fly ash geopolymer aggregateAlida, AbdullahKamarudin, HussinMohd Mustafa Al Bakri, AbdullahZarina, YahyaSochacki, WojciechRafiza, Abd RazakBłoch, KatarzynaHamzah, Fansurihttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747602022-03-23T01:46:49Z2021-02-01T00:00:00ZThe effects of various concentrations of NaOH on the inter-particle gelation of a fly ash geopolymer aggregate
Alida, Abdullah; Kamarudin, Hussin; Mohd Mustafa Al Bakri, Abdullah; Zarina, Yahya; Sochacki, Wojciech; Rafiza, Abd Razak; Błoch, Katarzyna; Hamzah, Fansuri
Aggregates can be categorized into natural and artificial aggregates. Preserving natural resources is crucial to ensuring the constant supply of natural aggregates. In order to preserve these natural resources, the production of artificial aggregates is beginning to gain the attention of researchers worldwide. One of the methods involves using geopolymer technology. On this basis, this current research focuses on the inter-particle effect on the properties of fly ash geopolymer aggregates with different molarities of sodium hydroxide (NaOH). The effects of synthesis parameters (6, 8, 10, 12, and 14 M) on the mechanical and microstructural properties of the fly ash geopolymer aggregate were studied. The fly ash geopolymer aggregate was palletized manually by using a hand to form a sphere-shaped aggregate where the ratio of NaOH/Na2SiO3 used was constant at 2.5. The results indicated that the NaOH molarity has a significant effect on the impact strength of a fly ash geopolymer aggregate. The highest aggregate impact value (AIV) was obtained for samples with 6 M NaOH molarity (26.95%), indicating the lowest strength among other molarities studied and the lowest density of 2150 kg/m3. The low concentration of sodium hydroxide in the alkali activator solution resulted in the dissolution of fly ash being limited; thus, the inter-particle volume cannot be fully filled by the precipitated gels.
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2021-02-01T00:00:00ZRole of sintering temperature in production of nepheline ceramics-based geopolymer with addition of ultra-high molecular weight polyethyleneRomisuhani, AhmadMohd Mustafa Al Bakri, AbdullahWan Mastura, Wan IbrahimKamarudin, HussinFakhryna Hannanee, Ahmad ZaidiJitrin, ChaiprapaWysłocki, Jerzy J.Bloch, KatarzynaNabiałek, Marcinhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747572022-03-23T01:36:21Z2021-02-01T00:00:00ZRole of sintering temperature in production of nepheline ceramics-based geopolymer with addition of ultra-high molecular weight polyethylene
Romisuhani, Ahmad; Mohd Mustafa Al Bakri, Abdullah; Wan Mastura, Wan Ibrahim; Kamarudin, Hussin; Fakhryna Hannanee, Ahmad Zaidi; Jitrin, Chaiprapa; Wysłocki, Jerzy J.; Bloch, Katarzyna; Nabiałek, Marcin
The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm−1 becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.
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2021-02-01T00:00:00ZStrength development and elemental distribution of dolomite/fly ash geopolymer composite under elevated temperatureEmy Aizat, AzimiMohd Mustafa Al Bakri, AbdullahVizureanu, PetricaMohd Arif Anuar, Mohd SallehSandu, Andrei VictorChaiprapa, JitrinYoriya, SorachonKamarudin, HussinIkmal Hakem, Azizhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747482022-03-22T02:11:19Z2020-02-01T00:00:00ZStrength development and elemental distribution of dolomite/fly ash geopolymer composite under elevated temperature
Emy Aizat, Azimi; Mohd Mustafa Al Bakri, Abdullah; Vizureanu, Petrica; Mohd Arif Anuar, Mohd Salleh; Sandu, Andrei Victor; Chaiprapa, Jitrin; Yoriya, Sorachon; Kamarudin, Hussin; Ikmal Hakem, Aziz
A geopolymer has been reckoned as a rising technology with huge potential for application across the globe. Dolomite refers to a material that can be used raw in producing geopolymers. Nevertheless, dolomite has slow strength development due to its low reactivity as a geopolymer. In this study, dolomite/fly ash (DFA) geopolymer composites were produced with dolomite, fly ash, sodium hydroxide, and liquid sodium silicate. A compression test was carried out on DFA geopolymers to determine the strength of the composite, while a synchrotron Micro-Xray Fluorescence (Micro-XRF) test was performed to assess the elemental distribution in the geopolymer composite. The temperature applied in this study generated promising properties of DFA geopolymers, especially in strength, which displayed increments up to 74.48 MPa as the optimum value. Heat seemed to enhance the strength development of DFA geopolymer composites. The elemental distribution analysis revealed exceptional outcomes for the composites, particularly exposure up to 400 °C, which signified the homogeneity of the DFA composites. Temperatures exceeding 400 °C accelerated the strength development, thus increasing the strength of the DFA composites. This appears to be unique because the strength of ordinary Portland Cement (OPC) and other geopolymers composed of other raw materials is typically either maintained or decreases due to increased heat
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2020-02-01T00:00:00ZCompressive strength and thermal conductivity of metakaolin geopolymers with anisotropic insulationsNur Ain, JayaYun-Ming, LiewMohd Mustafa Al Bakri, AbdullahKamarudin, HussinCheng Yong, HeahRidho, BayuajiMuhammad Faheem, Mohd Tahirhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747052022-03-17T03:21:17Z2020-02-01T00:00:00ZCompressive strength and thermal conductivity of metakaolin geopolymers with anisotropic insulations
Nur Ain, Jaya; Yun-Ming, Liew; Mohd Mustafa Al Bakri, Abdullah; Kamarudin, Hussin; Cheng Yong, Heah; Ridho, Bayuaji; Muhammad Faheem, Mohd Tahir
This research investigated the properties of thermally insulating geopolymer prepared using waste filler (fibreboard and rubber) to act as anisotropic pore/insulation. The geopolymer matrix was synthesised using metakaolin and an alkaline solution consists of sodium hydroxide solution and sodium silicate mixture. Geopolymers with varying content (0, 3, 5 and 7 layers) of coin-shaped fibreboard and expanded polystyrene are produced to examine the anisotropic insulation effect on the material characteristics. The compressive strength and thermal conductivity were determined experimentally. From the results, it is proved that the use of anisotropic insulations can improve the thermal conductivity and minimizing the reduction of compressive strength. Geopolymer incorporated with fibreboard had better performance in terms of strength while geopolymer incorporated with rubber had better thermal conductivity.
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2020-02-01T00:00:00Z