Rafiza Abd Razak
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Preferred name
Rafiza Abd Razak
Official Name
Rafiza, Abd Razak
Alternative Name
Rafiza, Abd Razak
Rafiza, Abdul Razak
Abdul Razak, Rafiza
Rafiza, R. A.
Razak, Rafiza Abd
Rafiza, A. R.
Abdul Razak, R.
Razak, R. A.
Razak, Rafiza Abdul
Razak, A. R.
Abd Razak, R.
Main Affiliation
Scopus Author ID
51161919900
Researcher ID
AAL-1501-2020

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  • Publication
    Finite element analysis on structural behaviour of geopolymer reinforced concrete beam using Johnson-Cook damage in Abaqus
    ( 2022-01-01)
    Nurul Aida Mohd Mortar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Kamarudin Hussin
    ;
    Rafiza Abd Razak
    ;
    Sanusi Hamat
    ;
    Hilmi A.H.
    ;
    Shahedan N.N.
    ;
    Li L.Y.
    ;
    Aziz I.H.A.
    This paper details a finite element analysis of the behaviour of Si-Al geopolymer concrete beam reinforced steel bar under an impulsive load and hyper velocity speed up to 1 km/s created by an air blast explosion. The initial torsion stiffness and ultimate torsion strength of the beam increased with increasing compressive strength and decreasing stirrup ratio. The study involves building a finite element model to detail the stress distribution and compute the level of damage, displacement, and cracks development on the geopolymer concrete reinforcement beam. This was done in ABAQUS, where a computational model of the finite element was used to determine the elasticity, plasticity, concrete tension damages, concrete damage plasticity, and the viability of the Johnson-Cook Damage method on the Si-Al geopolymer concrete. The results from the numerical simulation show that an increase in the load magnitude at the midspan of the beam leads to a percentage increase in the ultimate damage of the reinforced geopolymer beams failing in shear plastic deformation. The correlation between the numerical and experimental blasting results confirmed that the damage pattern accurately predicts the response of the steel reinforcement Si-Al geopolymer concrete beams, concluded that decreasing the scaled distance from 0.298 kg/m3 to 0.149 kg/m3 increased the deformation percentage.
  • Publication
    FINITE ELEMENT ANALYSIS ON STRUCTURAL BEHAVIOUR OF GEOPOLYMER REINFORCED CONCRETE BEAM USING JOHNSON-COOK DAMAGE IN ABAQUS
    ( 2022-01-01)
    Nurul Aida Mohd Mortar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Kamarudin Hussin
    ;
    Rafiza Abd Razak
    ;
    Sanusi Hamat
    ;
    Ahmad Humaizi Hilmi
    ;
    Noorfifi Natasha Shahedan
    ;
    Li L.Y.
    ;
    Ikmal Hakem Abdul Aziz
    This paper details a finite element analysis of the behaviour of Si-Al geopolymer concrete beam reinforced steel bar under an impulsive load and hyper velocity speed up to 1 km/s created by an air blast explosion. The initial torsion stiffness and ultimate torsion strength of the beam increased with increasing compressive strength and decreasing stirrup ratio. The study involves building a finite element model to detail the stress distribution and compute the level of damage, displacement, and cracks development on the geopolymer concrete reinforcement beam. This was done in ABAQUS, where a computational model of the finite element was used to determine the elasticity, plasticity, concrete tension damages, concrete damage plasticity, and the viability of the Johnson-Cook Damage method on the Si-Al geopolymer concrete. The results from the numerical simulation show that an increase in the load magnitude at the midspan of the beam leads to a percentage increase in the ultimate damage of the reinforced geopolymer beams failing in shear plastic deformation. The correlation between the numerical and experimental blasting results confirmed that the damage pattern accurately predicts the response of the steel reinforcement Si-Al geopolymer concrete beams, concluded that decreasing the scaled distance from 0.298 kg/m3 to 0.149 kg/m3 increased the deformation percentage.
      1
  • Publication
    Seawater Exposure Effect on Fly Ash based Geopolymer Concrete with Inclusion of Steel Fiber
    ( 2020-03-18)
    Zarina Yahya
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Jing L.Y.
    ;
    Li L.Y.
    ;
    Rafiza Abd Razak
    Concrete is widely used in construction offshore such as concrete floating bridges and sea tank. This research is providing an alternative construction material to replace ordinary Portland cement (OPC) concrete known as geopolymer. The geopolymer concrete was produced by mixing fly ash with alkaline activator and 3% of steel fibre in order to improve the properties of fiber reinforced geopolymer concrete (FRGPC). The effects of aging period in term of strength, changes in weight and carbonation of FRGPC in seawater is investigated and compared with the fiber reinforced concrete (FROPC). The compressive strength obtained for FRGPC were higher than FROPC. The highest compressive strength obtained by FRGPC is 76.87 MPa at 28 days and 45.63 MPa at 28 days for FROPC concrete. The compressive strength was decreased as the period of immersing the concrete in seawater is increased. During the immersion process of both samples in seawater up to 120 days, the carbonation was not detected even though with the existence of steel fibres.
      1