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

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  • Publication
    Evaluation on the rheological and mechanical properties of concrete incorporating eggshell with tire powder
    ( 2021)
    Rokiah Othman
    ;
    Beng Wei Chong
    ;
    Ramadhansyah Putra Jaya
    ;
    Mohd Rosli Mohd Hasan
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Mohd Haziman Wan Ibrahim
    The construction industry is the largest consumer of raw materials which are under the risk of exhaustion and depletion in the near future, which has prompted the usage of waste materials for the conservation of resource and as a solution for waste management. Two wastes that are widely produced but often inefficiently disposed are eggshell and waste tire. Hence, this paper aims to evaluate the rheological and mechanical properties of concrete incorporating eggshell and waste tire rubber using Response Surface Methodology (RSM). Concrete with eggshell as cement replacement and waste tire rubber as sand replacement was prepared with an interval of 5% up to 15% replacement of both materials. Rheological properties of concrete were accessed using slump cone test while mechanical properties were studied through compressive strength and flexural strength test. Result showed that eggshell replacement has a minor effect on concrete slump while tire rubber reduces workability considerably. Result also showed that concrete mechanical strength was optimum at 5% and 10% eggshell replacement, while tire rubber reduced mechanical strength with percentage of replacement. Non-destructive tests indicated that concrete has excellent quality but excessive tire replacement beyond 10% compromised structural integrity of concrete. Overall, RSM models were able to model the properties of concrete with high accuracy and minimal deviation.
  • 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.
  • Publication
    Effectiveness of dimple microtextured copper substrate on performance of Sn-0.7Cu solder alloy
    ( 2022)
    Siti Faqihah Roduan
    ;
    Juyana A. Wahab
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Nurul Aida Husna Mohd Mahayuddin
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Aiman Bin Mohd Halil
    ;
    Amira Qistina Syamimi Zaifuddin
    ;
    Mahadzir Ishak Muhammad
    ;
    Andrei Victor Sandu
    ;
    Mădălina Simona Baltatu
    ;
    Petrica Vizureanu
    This paper elucidates the influence of dimple-microtextured copper substrate on the performance of Sn-0.7Cu solder alloy. A dimple with a diameter of 50 µm was produced by varying the dimple depth using different laser scanning repetitions, while the dimple spacing was fixed for each sample at 100 µm. The dimple-microtextured copper substrate was joined with Sn-0.7Cu solder alloy using the reflow soldering process. The solder joints’ wettability, microstructure, and growth of its intermetallic compound (IMC) layer were analysed to determine the influence of the dimple-microtextured copper substrate on the performance of the Sn-0.7Cu solder alloy. It was observed that increasing laser scan repetitions increased the dimples’ depth, resulting in higher surface roughness. In terms of soldering performance, it was seen that the solder joints’ average contact angle decreased with increasing dimple depth, while the average IMC thickness increased as the dimple depth increased. The copper element was more evenly distributed for the dimple-micro-textured copper substrate than its non-textured counterpart.
  • Publication
    Meta-analysis of studies on eggshell concrete using mixed regression and response surface methodology
    ( 2023)
    Beng Wei Chong
    ;
    Rokiah Othman
    ;
    Ramadhansyah Putra Jaya
    ;
    Xiaofeng Li
    ;
    Mohd Rosli Mohd Hasan
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Eggshell concrete is an innovative green material that helps to recycle eggshell waste while reducing the environmental harm caused by excessive cement production. However, recent studies on eggshell concrete are limited, and the outcomes may vary due to the variation of mix design. The design of the experiment is used to simplify and optimize the study of sustainable concrete, yet analysis involving eggshell concrete is still scarce. This paper aimed to develop mathematical models for the prediction of eggshell concrete compressive strength using mixed regression (MR) and response surface methodology (RSM). Overall, 43 datasets were collected from available studies in the literature on eggshell powder as partial cement replacement. The input variables used were the percentage of eggshell, percentage of Ground Granulated Blast-furnace Slag (GGBS), cement content, fine aggregate, coarse aggregate, water, and Conplast SP-430 superplasticizer. The analysis of the contour plot concluded that eggshell powder increased the concrete compressive strength at an optimal replacement percentage between 5% and 10%. However, the partial cement replacement with eggshell powder is more optimal for mix design with higher water content. The statistical results of the model, such as R2, adjusted R2, and root-mean-square error (RMSE), indicated that both MR and RSM models are powerful tools to formulate and predict the eggshell concrete compressive strength. However, RSM models showed better accuracy and lower deviation.
  • Publication
    Effect of kaolin geopolymer ceramics addition on the microstructure and shear strength of Sn-3.0Ag-0.5Cu solder joints during multiple reflow
    ( 2022)
    Nur Syahirah Mohamad Zaimi
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Nur Izzati Muhammad Nadzri
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    ;
    Mohd Izrul Izwan Ramli
    ;
    Kazuhiro Nogita
    ;
    Hideyuki Yasuda
    ;
    Ioan Gabriel Sandu
    Solder interconnection in three-dimensional (3D) electronic packaging is required to undergo multiple reflow cycles of the soldering process. This paper elucidates the effects of multiple reflow cycles on the solder joints of Sn-3.0Ag-0.5Cu (SAC305) lead (Pb)-free solder with the addition of 1.0 wt.% kaolin geopolymer ceramics (KGC). The samples were fabricated using powder metallurgy with the hybrid microwave sintering method. Apart from using conventional cross-sectioned microstructure imaging, advanced synchrotron real-time in situ imaging was used to observe primary IMC formation in SAC305-KGC solder joints subjected to multiple reflow soldering. The addition of KGC particles in SAC305 suppressed the Cu6Sn5 IMC’s growth as primary and interfacial layers, improving the shear strength after multiple reflow soldering. The growth rate constant for the interfacial Cu6Sn5 IMC was also calculated in this study. The average growth rate of the primary Cu6Sn5 IMCs decreased from 49 µm/s in SAC305 to 38 µm/s with the addition of KGC particles. As a result, the average solidified length in the SAC305-KGC is shorter than SAC305 for multiple reflow soldering. It was also observed that with KGC additions, the growth direction of the primary Cu6Sn5 IMC in SAC305 changed from one growth to two growth directions. The observed results can be attributed to the presence of KGC particles both at grains of interfacial Cu6Sn5 IMCs and at the surface of primary Cu6Sn5 IMC.
  • Publication
    Wettability of Sn-3.0Ag-0.5Cu solder reinforced with TiO2 and Al2O3 nanoparticles at different reflow times
    ( 2023)
    Nur Haslinda Mohamed Muzni
    ;
    Ervina Efzan Mhd Noor
    ;
    Mohd. Mustafa Al Bakri Abdullah
    This study investigated the influence of reinforcing 0.50 wt.% of titanium oxide (TiO2) and aluminium oxide (Al2O3) nanoparticles on the wettability performance of a Sn-3.0Ag-0.5Cu (SAC305) solder alloy. The thermal properties of the SAC305 nanocomposite solder are comparable with thos of an SAC305 solder with a peak temperature window within a range of 240 to 250 °C. The wetting behaviour of the non-reinforced and reinforced SAC305 nanocomposite solder was determined and measured using the contact angle and spreading area and the relationships between them were studied. There is an increment in the spreading area (5.6 to 7.32 mm) by 30.71% and a reduction in the contact angle (26.3 to 18.6°) by 14.29% with an increasing reflow time up to 60 s when reinforcing SAC305 solder with 0.50 wt.% of TiO2 and Al2O3 nanoparticles. The SAC305 nanocomposite solder has a better wetting performance compared with the SAC305 solder. As the reflow time increased, the spreading area increased and the contact angle decreased, which restricted intermetallic compound growth and thus improved wettability performance
  • Publication
    Effect of bolt configurations on stiffness for steel-wood-steel connection loaded parallel to grain for softwoods in Malaysia
    ( 2022)
    Nur Liza Rahim
    ;
    Francis Ting Shyue Sheng
    ;
    Abdul Razak Abdul Karim
    ;
    Marcin Nabialek
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Marek Sroka
    Steel-wood-steel connection is widely seen in many applications, such as timber structures. The stiffness of steel-wood-steel connection loaded parallel to grain for softwoods originated from Malaysia was investigated in this study. Numerical models have been developed in ABAQUS to study the stiffness connection. Softwoods of Damar Minyak and Podo have been selected in this analysis. The comprehensive study focused on the effect of bolt configurations on stiffness. Numerical analysis is carried out and the developed model has been validated with the previous study. Further investigations have been made by using the validated model. From this model, numerical analysis of the stiffness values have been made for various bolt configurations, including bolt diameter, end distance, bolt spacing, number of rows and bolts and edge distance. The result shows that the stiffness of bolted timber connections for softwood depends on the bolt diameter, number of rows and bolts, end distance and edge distance. Based on the result, stiffness increased as the diameter of the bolt, end distance, number of rows and bolts and edge distance increased. It is also discovered that the stiffness equation in Eurocode 5 (EC5) is inadequate as the equation only considered parameters which are wood density and bolt diameter. Other connection parameters such as geometry are not considered in the EC5 equation.
  • Publication
    Comparative study on early strength of sodium hydroxide (NaOH) activated fly ash based geopolymer
    ( 2017-09-29)
    Zarina Yahya
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Siti Zulaikha Abd Talib
    ;
    Rafiza Abd Razak
    The urge to reduce carbon dioxide (CO2) emission has encourage researchers to introduce environmental friendly binder or known as geopolymer. This new binder was produced by mixing source materials rich in silica and alumina with alkaline liquids. For this study, class F fly ash was used as source material with two different types of alkaline activator; sodium hydroxide (NaOH) only and a combination of water glass with NaOH. The different concentration of the NaOH solutions (8M, 10M, 12M and 14M) is used in the production of geopolymer. The parameters such as curing regime, solid/liquid ratio, and water glass/NaOH ratio are controlled in the study. The samples with combination of NaOH and water glass as alkaline activator were prepared by mixing these two solution and stirred for 2 minutes. Then this solution were mixed together with fly ash for 3 minutes and casted in the mould. The performance of the fly ash based geopolymer are evaluated by the compressive strength, water absorption and density at the early age of 1th, 3th and 7th days. Based on the study, at a concentration of 14M on 7th days had achieved the maximum compressive strength of 7.1 MPa for samples activated with NaOH only. Meanwhile, for geopolymer samples activated with a combination of the water glass and NaOH, the maximum strength of 33.33 MPa was recorded on 7th days of testing with NaOH concentration of 12 M. The water absorption for all geopolymer samples were ranging from 2.04 % to 2.78%, which are below the limit (3%). While the density of the geopolymer paste were in the range of 1552 kg/m3 to 1680 kg/m3, which are below the limit (2400 kg/m3). From the standpoint of strength of hardened geopolymer samples, the most effective alkaline activator in geopolymer is the combination of NaOH and water glass.
  • Publication
    Properties and behavior of geopolymer concrete subjected to explosive air blast loading: a review
    ( 2017)
    Nurul Aida Mohd Mortar
    ;
    Kamarudin Hussin
    ;
    Rafiza Abdul Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ahmad Humaizi Hilmi
    ;
    Andrei Victor Sandu
    The severe damage to civilian buildings, public area, jet aircraft impact and defense target under explosive blast loading can cause a huge property loss. Most of researcher discusses the topics on design the concrete material model to sustain againts the explosive detonation. The implementation of modern reinforcement steels and fibres in ordinary Portland cement (OPC) concrete matrix can reduce the extreme loading effects. However, most researchers have proved that geopolymer concrete (GPC) has better mechanical properties towards high performance concrete, compared to OPC. GPC has the high early compressive strength and high ability to resist the thermal energy from explosive detonation. In addition, OPC production is less environmental friendly than geopolymer cement. Geopolymer used can lead to environmental protection besides being improved in mechanical properties. Thus, this paper highlighted on an experimental, numerical and the analytical studies cause of the explosive detonation impact to concrete structures.
  • Publication
    Correlation Study on the Effect of Sintering Mechanism with the Properties of Geopolymer-Based Ceramic
    ( 2023-01-01)
    Nur Bahijah M.
    ;
    Romisuhani Ahmad
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Wan Mastura Wan Ibrahim
    Nepheline geopolymer-based ceramics are emerging as a promising alternative to traditional ceramics due to their eco-friendly production and sustainable nature. Therefore, this study aims to comprehensively investigate the relationship between mechanical behaviour and sintering mechanisms in the production of kaolin geopolymer-based nepheline ceramics. Sodium hydroxide and sodium silicate were mixed to act as the alkaline activator to facilitate the geopolymerization process. The experimental analysis involved varying the sintering temperature within the range of 200°C to 1200°C. The findings from the correlation study highlight that the flexural strength and densification process is in linear relation with R2 of 0.9369, whilst the water absorption and volumetric shrinkage exhibited an inversely linear relationship with the R2 value of 0.8733. The maximum flexural strength of 78.92 MPa and density of 2.56 g/cm3 were achieved when sintered at 1200°C. Meanwhile, the water absorption decreases with the increase of volumetric shrinkage, which might relate to the densification process of the geopolymer-based nepheline ceramic. The outcome of this research contributes a deeper understanding of the interplay between mechanical behaviour and sintering mechanism, enabling the design of superior sintered materials.