Mohd. Mustafa Al Bakri Abdullah
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Preferred name
Mohd. Mustafa Al Bakri Abdullah
Official Name
Abdulah, Mohd. Mustafa Al Bakri
Alternative Name
Abdullah, M.M.A.
M.M.A. Abdullah
Mustafa Al Bakri, A. M.
Albakri Abdullah, M. M.
Main Affiliation
CeGeoGTech UniMAP
Scopus Author ID
53164519100

Research Output
Now showing 1 - 7 of 7
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Publication

Geopolymer-based artificial aggregates: a review on methods of producing, properties, and improving techniques

2022 , Mohammad Almadani , Rafiza Abd Razak , Mohd. Mustafa Al Bakri Abdullah , Rosnita Mohamed

The depletion of aggregate-related natural resources is the primary concern of all researchers globally. Recent studies emphasize the significance of recycling and reusing various types of natural or by-product material waste from industry as a result of the building industry’s rising demand for aggregate as the primary component in concrete production. It has been demonstrated that the geopolymer system has exceptional features, such as high strength, superior durability, and greater resistance to fire exposure, making it a viable alternative to ordinary Portland Cement (OPC) concrete. This study will examine the present method utilized to generate artificial aggregate-based geopolymers, including their physical and mechanical properties, as well as their characterization. The production process of geopolymer derived from synthetic aggregates will be highlighted. In conjunction with the bonding of aggregates and the cement matrix, the interfacial transition zone (ITZ) is highlighted in this work as an additional important property to be researched in the future. It will be discussed how to improve the properties of geopolymers based on artificial aggregates. It has been demonstrated that cold bonding provides superior qualities for artificial aggregate while conserving energy during production. The creation of ITZ has a significant impact on the bonding strength between artificial aggregates and the cement matrix. Additionally, improvement strategies demonstrate viable methods for enhancing the quality of manufactured aggregates. In addition, other recommendations are discussed in this study for future work.

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Influence of sintering temperature on the pore structure of an alkali-activated Kaolin based Geopolymer

2023 , Mohd Izrul Izwan Ramli , Mohd Arif Anuar Mohd Salleh , Ikmal Hakem A Aziz , Nur Syahirah Mohamad Zaimi , Siti Farahnabilah Muhd Amli , Mohd. Mustafa Al Bakri Abdullah

Kaolin-based geopolymers are alternatives for producing high-strength ceramics for construction materials. Creating high-performing kaolin ceramics utilizing the regular technique requires a high handling temperature (higher than 1200°C). Thus, the structure and properties such as pore size and distribution are affected at higher sintering temperatures. Along these lines, information with respect to the sintering system and related pore structure is essential for advancing the properties of the previously mentioned materials. This study investigated the microstructure and the density of a kaolin-based geopolymer at various sintering temperatures. The unsintered sample has the highest density of 1610 kg/cm3, while the samples sintered at 1100°C haves the lowest density of 1203 kg/cm3. The result also shows that increasing the sintering temperature to 1100°C resulted in increasing the water absorption of the kaolin-based geopolymer ceramic.

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Role of sintering temperature in production of nepheline ceramics-based geopolymer with addition of ultra-high molecular weight polyethylene

2022 , Romisuhani Ahmad , Mohd. Mustafa Al Bakri Abdullah , Wan Mastura Wan Ibrahim , Kamarudin Hussin , Jitrin Chaiprapa , Jerzy J. Wysłocki , Katarzyna Błoch , Fakhryna Hannanee Ahmad Zaidi , Marcin Nabiałek

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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Role of sintering temperature in production of nepheline ceramics-based geopolymer with addition of ultra-high molecular weight polyethylene

2021 , Romisuhani Ahmad , Mohd. Mustafa Al Bakri Abdullah , Jitrin Chaiprapa , Kamarudin Hussin , Wan Mastura Wan Ibrahim , Fakhryna Hannanee Ahmad Zaidi , Jerzy J. Wysłocki , Katarzyna Błoch , Marcin Nabiałek

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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The influence of sintering temperature on the pore structure of an Alkali-Activated Kaolin-Based Geopolymer Ceramic

2022 , Mohd Izrul Izwan Ramli , Mohd Arif Anuar Mohd Salleh , Mohd. Mustafa Al Bakri Abdullah , Ikmal Hakem Aziz , Tan Chi Ying , Noor Fifinatasha Shahedan , Winfried Kockelmann , Anna Fedrigo , Andrei Victor Sandu , Petrica Vizureanu , Jitrin Chaiprapa , Dumitru Doru Burduhos Nergis

Geopolymer materials are used as construction materials due to their lower carbon dioxide (CO2) emissions compared with conventional cementitious materials. An example of a geopolymer material is alkali-activated kaolin, which is a viable alternative for producing high-strength ceramics. Producing high-performing kaolin ceramics using the conventional method requires a high processing temperature (over 1200 °C). However, properties such as pore size and distribution are affected at high sintering temperatures. Therefore, knowledge regarding the sintering process and related pore structures on alkali-activated kaolin geopolymer ceramic is crucial for optimizing the properties of the aforementioned materials. Pore size was analyzed using neutron tomography, while pore distribution was observed using synchrotron micro-XRF. This study elucidated the pore structure of alkali-activated kaolin at various sintering temperatures. The experiments showed the presence of open pores and closed pores in alkali-activated kaolin geopolymer ceramic samples. The distributions of the main elements within the geopolymer ceramic edifice were found with Si and Al maps, allowing for the identification of the kaolin geopolymer. The results also confirmed that increasing the sintering temperature to 1100 °C resulted in the alkali-activated kaolin geopolymer ceramic samples having large pores, with an average size of ~80 µm3 and a layered porosity distribution.

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Geopolymer-based nepheline ceramics: effect of sintering profile on morphological characteristics and flexural strength

2022 , Romisuhani Ahmad , Wan Mastura Wan Ibrahim , Mohd. Mustafa Al Bakri Abdullah , Phakkhananan Pakawanit , Petrica Vizureanu , Arman Shah Abdullah , Andrei Victor Sandu , Fakhryna Hannanee Ahmad Zaidi

The focus of this study is the fabrication of innovative and sustainable ceramic-based geopolymer with improved low temperatures performances. Kaolin was mixed with liquid sodium silicate (Na₂SiO₃) and 12M of sodium hydroxide (NaOH) solution using alkali activator ratio of 0.24 and solid-to-liquid ratio of 1:1 to synthesize kaolin geopolymer. The effect of the sintering profile on the microstructure, pore evolution and flexural strength were investigated. The heating exposure aided consolidation and created a fairly uniform microstructure, resulting in a smooth surface texture. In comparison to the unheated geopolymer, 3D pore distribution showed a significant increase in the range size of ~30 µm with the appearance of isolated and intergranular pores. The flexural strength at 1200 °C with a heating rate of 5 °C/min and was increased by 146.4% to 85.4 MPa, as compared to the heating rate of 2 °C/min. The sintering process has an impact on the final microstructure formation thus improving the characteristic of geopolymer-based nepheline ceramic.

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Self-Fluxing mechanism in geopolymerization for Low-Sintering temperature of ceramic

2021 , Noorina Hidayu Jamil , Mohd. Mustafa Al Bakri Abdullah , Faizul Che Pa , Hasmaliza Mohamad , Wan Mohd Arif W Ibrahim , Penphitcha Amonpattaratkit , Joanna Gondro , Wojciech Sochacki , Norfadhilah Ibrahim

Kaolin, theoretically known as having low reactivity during geopolymerization, was used as a source of aluminosilicate materials in this study. Due to this concern, it is challenging to directly produce kaolin geopolymers without pre-treatment. The addition of ground granulated blast furnace slag (GGBS) accelerated the geopolymerization process. Kaolin–GGBS geopolymer ceramic was prepared at a low sintering temperature due to the reaction of the chemical composition during the initial stage of geopolymerization. The objective of this work was to study the influence of the chemical composition towards sintering temperature of sintered kaolin–GGBS geopolymer. Kaolin–GGBS geopolymer was prepared with a ratio of solid to liquid 2:1 and cured at 60 °C for 14 days. The cured geopolymer was sintered at different temperatures: 800, 900, 1000, and 1100 °C. Sintering at 900 °C resulted in the highest compressive strength due to the formation of densified microstructure, while higher sintering temperature led to the formation of interconnected pores. The difference in the X-ray absorption near edge structure (XANES) spectra was related to the phases obtained from the X-ray diffraction analysis, such as akermanite and anothite. Thermal analysis indicated the stability of sintered kaolin–GGBS geopolymer when exposed to 1100 °C, proving that kaolin can be directly used without heat treatment in geopolymers. The geopolymerization process facilitates the stability of cured samples when directly sintered, as well as plays a significant role as a self-fluxing agent to reduce the sintering temperature when producing sintered kaolin–GGBS geopolymers.

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