Ahmad Humaizi Hilmi
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Preferred name
Ahmad Humaizi Hilmi
Official Name
Ahmad Humaizi, Hilmi
Alternative Name
Hilmi, Ahmad Humaizi
Hilmi, A.
Humaizi, Ahmad
Hilmi, A. H
Main Affiliation
Scopus Author ID
57193311438
Researcher ID
W-1988-2019

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  • 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
    Finite element analysis on structural behaviour of geopolymer reinforced concrete beam using Johnson-Cook Damage in ABAQUS
    ( 2022)
    Nurul Aida Mohd Mortar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rafiza Abdul Razak
    ;
    Kamarudin Hussin
    ;
    Sanusi Hamat
    ;
    Ahmad Humaizi Hilmi
    ;
    Noorfifi Natasha Shahedan
    ;
    Long Yuan Li
    ;
    Ikmal Hakem A. 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.
      3  11
  • Publication
    Properties and behavior of geopolymer concrete subjected to explosive air blast loading: a review
    ( 2017)
    Nurul Aida Mohd Mortar
    ;
    Kamarudin Hussin
    ;
    Andrei Victor Sandu
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ahmad Humaizi Hilmi
    ;
    Rafiza Abdul Razak
    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.
      8  10
  • 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