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
    Challenges and impacts of COVID-19 pandemic on global waste management systems: a review
    ( 2022)
    Ismail Luhar
    ;
    Salmabanu Luhar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Unfortunately, nearly the whole world came to a standstill due to the coronavirus disease 2019, i.e., the COVID-19 pandemic, which negatively and severely impacted almost all facets of society, systems, and lives on the planet during the last few years. During this time, a surge in the generation of a huge volume of diverse wastes at an unprecedented rate occurred due to the extensive use of disposables and personal shielding safety gear such as personal protective equipment (PPE) for both infected and uninfected people as well as frontline staff, etc., as corona protocols, especially in the form of “plastic wastes”. Consequently, all these factors induced a novel route for the pollution of air, soil, and water, inviting a great number of health hazards in addition to the pandemic. Beyond a doubt, the susceptibility of the spread of the coronavirus through polluted waste is high, an issue for which the waste management measures are comparatively not up to the mark. The spread of COVID-19 forced the world into lockdown, which had both constructive and unconstructive effects on not only the environment but also systems such as the waste management sector, etc. The unforeseen increase in the quantity of waste created a challenge concerning normal waste disposal facilities, negatively impacting the global waste management industry, and hence, leading to an urgent situation internationally. Still, in developing nations, the sector of waste management is at its nascent stage, and therefore, the sector of waste management during the pandemic period has been influenced severely in many parts of the world. The current comprehensive review provides not only an overview of the impacts and challenges of COVID-19 on the waste management sector but also extends the systematic data of waste generation that has been made accessible so far along with a discussion on the safety of the related workers and staff as well as suggestions for the possible approaches towards better waste management services, which are essential to manage the waste increase resultant of the COVID-19 pandemic in a majority of nations.
  • Publication
    Influence of Polyformaldehyde Monofilament fiber on the engineering properties of foamed concrete
    ( 2022)
    Md Azree Othuman Mydin
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Mohd Nasrun Mohd Nawi
    ;
    Zarina Yahya
    ;
    Liyana Ahmad Sofri
    ;
    Madalina Simona Baltatu
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    Foamed concrete is considered a green building material, which is porous in nature. As a result, it poses benefits such as being light in self-weight, and also has excellent thermal insulation properties, environmental safeguards, good fire resistance performance, and low cost. Nevertheless, foamed concrete has several disadvantages such as low strength, a large amount of entrained air, poor toughness, and being a brittle material, all of which has restricted its usage in engineering and building construction. Hence, this study intends to assess the potential utilization of polypropylene fibrillated fiber (PFF) in foamed concrete to enhance its engineering properties. A total of 10 mixes of 600 and 1200 kg/m3 densities were produced by the insertion of four varying percentages of PFF (1%, 2%, 3%, and 4%). The properties assessed were splitting tensile, compressive and flexural strengths, workability, porosity, water absorption, and density. Furthermore, the correlations between the properties considered were also evaluated. The outcomes reveal that the foamed concrete mix with 4% PFF attained the highest porosity, with approximately 13.9% and 15.9% for 600 and 1200 kg/m3 densities in comparison to the control specimen. Besides, the mechanical properties (splitting tensile, compressive and flexural strengths) increased steadily with the increase in the PFF percentages up to the optimum level of 3%. Beyond 3%, the strengths reduced significantly due to poor PFF dispersal in the matrix, leading to a balling effect which causes a degraded impact of scattering the stress from the foamed concrete vicinity to another area of the PFF surface. This exploratory investigation will result in a greater comprehension of the possible applications of PFF in LFC. It is crucial to promote the sustainable development and implementation of LFC materials and infrastructures.
  • Publication
    Mechanical and microstructural evaluations of lightweight aggregate geopolymer concrete before and after exposed to elevated temperatures
    ( 2013)
    Omar Abdulkareem
    ;
    Mohd Abdullah
    ;
    Kamarudin Hussin
    ;
    Khairul Ismail
    ;
    Mohammed Binhussain
    This paper presents the mechanical and microstructural characteristics of a lightweight aggregate geopolymer concrete (LWAGC) synthesized by the alkali-activation of a fly ash source (FA) before and after being exposed to elevated temperatures, ranging from 100 to 800 °C. The results show that the LWAGC unexposed to the elevated temperatures possesses a good strength-to-weight ratio compared with other LWAGCs available in the published literature. The unexposed LWAGC also shows an excellent strength development versus aging times, up to 365 days. For the exposed LWAGC to the elevated temperatures of 100 to 800 °C, the results illustrate that the concretes gain compressive strength after being exposed to elevated temperatures of 100, 200 and 300 °C. Afterward, the strength of the LWAGC started to deteriorate and decrease after being exposed to elevated temperatures of 400 °C, and up to 800 °C. Based on the mechanical strength results of the exposed LWAGCs to elevated temperatures of 100 °C to 800 °C, the relationship between the exposure temperature and the obtained residual compressive strength is statistically analyzed and achieved. In addition, the microstructure investigation of the unexposed LWAGC shows a good bonding between aggregate and mortar at the interface transition zone (ITZ). However, this bonding is subjected to deterioration as the LWAGC is exposed to elevated temperatures of 400, 600 and 800 °C by increasing the microcrack content and swelling of the unreacted silicates.
  • Publication
    Performance of Sn-3.0Ag-0.5Cu composite solder with kaolin geopolymer ceramic reinforcement on microstructure and mechanical properties under isothermal ageing
    ( 2021)
    Nur Syahirah Mohamad Zaimi
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Andrei Victor Sandu
    ;
    Mohd Mustafa Al Bakri Abdullah
    ;
    Norainiza Saud
    ;
    Shayfull Zamree Abd Rahim
    ;
    Petrica Vizureanu
    ;
    Rita Mohd Said
    ;
    Mohd Izrul Izwan Ramli
    This paper elucidates the effect of isothermal ageing at temperature of 85 °C, 125 °C and 150 °C for 100, 500 and 1000 h on Sn-3.0Ag-0.5Cu (SAC305) lead-free solder with the addition of 1 wt% kaolin geopolymer ceramic (KGC) reinforcement particles. SAC305-KGC composite solders were fabricated through powder metallurgy using a hybrid microwave sintering method and reflowed on copper substrate printed circuit board with an organic solderability preservative surface finish. The results revealed that, the addition of KGC was beneficial in improving the total thickness of interfacial intermetallic compound (IMC) layer. At higher isothermal ageing of 150 °C and 1000 h, the IMC layer in SAC305-KGC composite solder was towards a planar-type morphology. Moreover, the growth of total interfacial IMC layer and Cu3Sn layer during isothermal ageing was found to be controlled by bulk diffusion and grain-boundary process, respectively. The activation energy possessed by SAC305-KGC composite solder for total interfacial IMC layer and Cu3Sn IMC was 74 kJ/mol and 104 kJ/mol, respectively. Based on a lap shear test, the shear strength of SAC305-KGC composite solder exhibited higher shear strength than non-reinforced SAC305 solder. Meanwhile, the solder joints failure mode after shear testing was a combination of brittle and ductile modes at higher ageing temperature and time for SAC305-KGC composite solder.
  • Publication
    The influence of Pre-Heated treatment to improve adhesion bond coating strength of fly ash based geopolymer ceramic
    ( 2018)
    L Jamaludin
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Kamarudin Hussin
    ;
    A Abdul Kadir
    The study focus on effect of pre-heated ceramic surface on the adhesion bond strength between geopolymer coating coating and ceramic substrates. Ceramic substrates was pre-heated at different temperature (400 °C, 600 °C, 800 °C and 1000 °C). Fly ash geopolymer coating material potential used to protect surface used in exposure conditions after sintering at high temperature. Fly ash and alkali activator (Al2O3/Na2SiO3) were mixed with 2.0 solids-toliquid ratios to prepare geopolymer coating material at constant NaOH concentration of 12M. Adhesion test was conducted to determine the adhesion bond between ceramic substrates and fly ash coating material. The results showed the pre-heated ceramic substrates effect the adhesion bond of coating compared with untreated substrates with increasing of strength up to 20 % for temperature 600 °C.
  • Publication
    Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to produce lightweight aggregate-based geopolymer
    ( 2015)
    Rafiza Razak
    ;
    Mohd Abdullah
    ;
    Kamarudin Hussin
    ;
    Khairul Ismail
    ;
    Djwantoro Hardjito
    ;
    Zarina Yahya
    This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced.
  • Publication
    Effect of sodium hydroxide molarity on physical, mechanical and thermal conductivity of metakaolin geopolymers
    ( 2018)
    Nur Ain Jaya
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Heah Cheng Yong
    ;
    Kamarudin Hussin
    In the present work, the effect of different sodium hydroxide (NaOH) molarity (6M, 8M, 10M, 12M and 14M) on the physical, mechanical and thermal conductivity of metakaolin geopolymers (MkGPs) was investigated. Geopolymers were prepared by activating the metakaolin with a mixture of NaOH with sodium silicate (Na2SiO3). The products obtained were characterized after 28 days of curing. The density, porosity, compressive strength and thermal conductivity (TC) were determined. In general, the NaOH molarity has a significant effect on the compressive strength of the MkGPs. The highest compressive strength was 14.6 MPa achieved with 10M of NaOH solution. The thermal conductivity of MkGPs measured in this work was low in the range between 0.71-0.97 W/mK. NaOH molarity had a significant effect on compressive strength but a marginal effect on thermal conductivity of MkGPs. The thermal conductivity was mainly affected by the bulk density and thus the total porosity. The results showed that the geopolymer can be considered to be used as the thermal insulating material.
  • Publication
    Strength development and elemental distribution of Dolomite/Fly Ash geopolymer composite under elevated temperature
    ( 2020)
    Emy Aizat Azimi
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Petrica Vizureanu
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Andrei Victor Sandu
    ;
    Jitrin Chaiprapa
    ;
    Sorachon Yoriya
    ;
    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.
  • Publication
    Characterisation at the bonding zone between fly ash based Geopolymer Repair Materials (GRM) and Ordinary Portland Cement Concrete (OPCC)
    ( 2020)
    Warid Wazien Ahmad Zailani
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Mohd Fadzil Arshad
    ;
    Rafiza Abd Razak
    ;
    Muhammad Faheem Mohd. Tahir
    ;
    Remy Rozainy Mohd Arif Zainol
    ;
    Marcin Nabialek
    ;
    Andrei Victor Sandu
    ;
    Jerzy J. Wysłocki
    ;
    Katarzyna Błoch
    In recent years, research and development of geopolymers has gained significant interest in the fields of repairs and restoration. This paper investigates the application of a geopolymer as a repair material by implementation of high-calcium fly ash (FA) as a main precursor, activated by a sodium hydroxide and sodium silicate solution. Three methods of concrete substrate surface preparation were cast and patched: as-cast against ordinary Portland cement concrete (OPCC), with drilled holes, wire-brushed, and left as-cast against the OPCC grade 30. This study indicated that FA-based geopolymer repair materials (GRMs) possessed very high bonding strength at early stages and that the behavior was not affected significantly by high surface treatment roughness. In addition, the investigations using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy have revealed that the geopolymer repair material became chemically bonded to the OPC concrete substrate, due to the formation of a C–A–S–H gel. Fundamentally, the geopolymer network is composed of tetrahedral anions (SiO4)4− and (AlO4)5− sharing the oxygen, which requires positive ions such as Na+, K+, Li+, Ca2+, Na+, Ba2+, NH4+, and H3O+. The availability of calcium hydroxide (Ca(OH)2) at the surface of the OPCC substrate, which was rich in calcium ions (Ca2+), reacted with the geopolymer; this compensated the electron vacancies of the framework cavities at the bonding zone between the GRM and the OPCC substrate.
  • Publication
    Hybrid mold : Comparative study of rapid and hard tooling for injection molding application using Metal Epoxy Composite (MEC)
    ( 2021)
    Radhwan Hussin
    ;
    Safian Sharif
    ;
    Marcin Nabiałek
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Mohd Tanwyn Mohd Khushairi
    ;
    Jerzy J. Wysłocki
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Mohd. Hazwan Mohd. Hanid
    ;
    Mohd Azlan Suhaimi
    ;
    Katarzyna Błoch
    The mold-making industry is currently facing several challenges, including new competitors in the market as well as the increasing demand for a low volume of precision moldings. The purpose of this research is to appraise a new formulation of Metal Epoxy Composite (MEC) materials as a mold insert. The fabrication of mold inserts using MEC provided commercial opportunities and an alternative rapid tooling method for injection molding application. It is hypothesized that the addition of filler particles such as brass and copper powders would be able to further increase mold performance such as compression strength and thermal properties, which are essential in the production of plastic parts for the new product development. This study involved four phases, which are epoxy matrix design, material properties characterization, mold design, and finally the fabrication of the mold insert. Epoxy resins filled with brass (EB) and copper (EC) powders were mixed separately into 10 wt% until 30 wt% of the mass composition ratio. Control factors such as degassing time, curing temperature, and mixing time to increase physical and mechanical properties were optimized using the Response Surface Method (RSM). The study provided optimum parameters for mixing epoxy resin with fillers, where the degassing time was found to be the critical factor with 35.91%, followed by curing temperature with 3.53% and mixing time with 2.08%. The mold inserts were fabricated for EB and EC at 30 wt% based on the optimization outcome from RSM and statistical ANOVA results. It was also revealed that the EC mold insert offers better cycle time compared to EB mold insert material.