Mohd. Mustafa Al Bakri Abdullah
Thumbnail Image
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

Filters

6 1
6
Reset filters

Settings
Now showing 1 - 6 of 6
  • Publication
    Behavior of alkali-activated fly ash through underwater placement
    ( 2021-11-01)
    Zarina Yahya
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Li Long-Yuan
    ;
    Nergis D.D.B.
    ;
    Muhammad Aiman Asyraf Zainal Hakimi
    ;
    Sandu A.V.
    ;
    Vizureanu P.
    ;
    Rafiza Abd Razak
    Underwater concrete is a cohesive self-consolidated concrete used for concreting underwater structures such as bridge piers. Conventional concrete used anti-washout admixture (AWA) to form a high-viscosity underwater concrete to minimise the dispersion of concrete material into the surrounding water. The reduction of quality for conventional concrete is mainly due to the washing out of cement and fine particles upon casting in the water. This research focused on the detailed investigations into the setting time, washout effect, compressive strength, and chemical composition analysis of alkali-activated fly ash (AAFA) paste through underwater placement in seawater and freshwater. Class C fly ash as source materials, sodium silicate, and sodium hydroxide solution as alkaline activator were used for this study. Specimens produced through underwater placement in seawater showed impressive performance with strength 71.10 MPa on 28 days. According to the Standard of the Japan Society of Civil Engineers (JSCE), the strength of specimens for underwater placement must not be lower than 80% of the specimen’s strength prepared in dry conditions. As result, the AAFA specimens only showed 12.11% reduction in strength compared to the specimen prepared in dry conditions, thus proving that AAFA paste has high potential to be applied in seawater and freshwater applications.
      2
  • Publication
    Thermal insulation and mechanical properties in the presence of glass bubble in fly ash geopolymer paste
    ( 2022-01-01)
    Noor Fifinatasha Shahedan
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Norsuria Mahmed
    ;
    Liew Yun Ming
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Ikmal Hakem Abdul Aziz
    ;
    Kadir A.A.
    ;
    Sandu A.V.
    ;
    Mohd Fathullah Ghazli@Ghazali
    The density, compressive strength, and thermal insulation properties of fly ash geopolymer paste are reported. Novel insulation material of glass bubble was used as a replacement of fly ash binder to significantly enhance the mechanical and thermal properties compared to the geopolymer paste. The results showed that the density and compressive strength of 50% glass bubble was 1.45 g/ cm3 and 42.5 MPa, respectively, meeting the standard requirement for structural concrete. Meanwhile, the compatibility of 50% glass bubbles tested showed that the thermal conductivity (0.898 W/mK), specific heat (2.141 MJ/m3K), and thermal diffusivity (0.572 mm2/s) in meeting the same requirement. The improvement of thermal insulation properties revealed the potential use of glass bubbles as an insulation material in construction material.
      1  37
  • Publication
    Thermal Insulation and Mechanical Properties in the Presence of Glas Bubble in Fly Ash Geopolymer Paste
    ( 2022-01-01)
    Shahedan N.F.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Norsuria Mahmed
    ;
    Liew Yun Ming
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Aziz I.H.A.
    ;
    Kadir A.A.
    ;
    Sandu A.V.
    ;
    Mohd Fathullah Ghazli@Ghazali
    The density, compressive strength, and thermal insulation properties of fly ash geopolymer paste are reported. Novel insulation material of glass bubble was used as a replacement of fly ash binder to significantly enhance the mechanical and thermal properties compared to the geopolymer paste. The results showed that the density and compressive strength of 50% glass bubble was 1.45 g/ cm3 and 42.5 MPa, respectively, meeting the standard requirement for structural concrete. Meanwhile, the compatibility of 50% glass bubbles tested showed that the thermal conductivity (0.898 W/mK), specific heat (2.141 MJ/m3K), and thermal diffusivity (0.572 mm2/s) in meeting the same requirement. The improvement of thermal insulation properties revealed the potential use of glass bubbles as an insulation material in construction material.
      40  8
  • Publication
    Thermal insulation and mechanical properties in the presence of glass bubble in fly ash geopolymer paste
    ( 2022-01-01)
    Noor Fifinatasha Shahedan
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Norsuria Mahmed
    ;
    Liew Yun Ming
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Ikmal Hakem Abdul Aziz
    ;
    Kadir A.A.
    ;
    Sandu A.V.
    ;
    Mohd Fathullah Ghazli@Ghazali
    The density, compressive strength, and thermal insulation properties of fly ash geopolymer paste are reported. Novel insulation material of glass bubble was used as a replacement of fly ash binder to significantly enhance the mechanical and thermal properties compared to the geopolymer paste. The results showed that the density and compressive strength of 50% glass bubble was 1.45 g/ cm3 and 42.5 MPa, respectively, meeting the standard requirement for structural concrete. Meanwhile, the compatibility of 50% glass bubbles tested showed that the thermal conductivity (0.898 W/mK), specific heat (2.141 MJ/m3K), and thermal diffusivity (0.572 mm2/s) in meeting the same requirement. The improvement of thermal insulation properties revealed the potential use of glass bubbles as an insulation material in construction material.
      1
  • Publication
    Effect of Solid-to-Liquid Ratio on Thin Fly Ash Geopolymer
    ( 2020-03-18)
    Yong-Sing N.
    ;
    Liew Yun Ming
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Hui-Teng N.
    ;
    Kamarudin Hussin
    ;
    Heah Cheng Yong
    ;
    Nurul Aida Mohd Mortar
    ;
    Sandu A.V.
    The present work studies the effect of solid-to-liquid (S/L) ratio on the properties of thin fly ash-based geopolymer. The fly ash geopolymers with dimension of 160 mm × 40 mm × 10 mm were synthesised by using various S/L ratios (1.5, 2.0, 2.5, 3.0 and 3.2). The alkali activator was prepared by mixing 10M sodium hydroxide (NaOH) solution and sodium silicate (Na2SiO3) with the Na2SiO3/NaOH ratio of 2.5. The samples were cured at 60°C for 6 hours. The performance of fly ash geopolymers was evaluated by testing the flexural strength after 28 days. Results showed that the S/L ratio had an effect on flexural strength. The optimum flexural strength of 5.12 MPa was achieved by the fly ash geopolymer with S/L ratio of 2.5. However, the flexural strength dropped with higher S/L ratio as the workability decreases. However, further experimental lab work should be carried out as there is less knowledge in the study on the flexural strength of thin fly ash geopolymer.
      1  28
  • Publication
    Silica Bonding Reaction on Fly Ash Based Geopolymer Repair Material System with Incorporation of Various Concrete Substrates
    ( 2022-01-01)
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ikmal Hakem A. Aziz
    ;
    Zailani W.W.A.
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Heah Cheng Yong
    ;
    Sandu A.V.
    ;
    Loke Siu Peng
    This paper presents an experimental investigation on the mechanical properties and microstructure of geopolymer repair materials mixed using fly ash (FA) and concrete substrates. An optimal combination of FA and concrete substrate was determined using the compressive test of geopolymer mortar mixed with various concrete substrate classes. It was found that the contribution of (C35/45) concrete substrates with the FA geopolymer mortar increases the 28-day bonding strength by 25.74 MPa. The microstructure analysis of the samples using scanning electron microscopy showed the denser structure owing to the availability of high calcium and iron elements distribution. These metal cations (Ca2+ and Fe3+) are available at OPC concrete substrate as a result from the hydration process reacted with alumina-silica sources of FA and formed calcium aluminate silicate hydrate (C-A-S-H) gels and Fe-bonding linkages.
      3