Rafiza Abd Razak
Thumbnail Image
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

Research Output

Filters

55
Reset filters

Settings
Now showing 1 - 10 of 55
  • 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
    The effect of various waste materials' contents on the attenuation level of anti-radiation shielding concrete
    ( 2013)
    Ali Azeez
    ;
    Kahtan Mohammed
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Kamarudin Hussin
    ;
    Sandu, Andrei Victor
    ;
    Rafiza Abd Razak
    Samples of concrete contain various waste materials, such as iron particulates, steel balls of used ball bearings and slags from steel industry were assessed for their anti-radiation attenuation coefficient properties. The attenuation measurements were performed using gamma spectrometer of NaI (Tl) detector. The utilized radiation sources comprised 137Cs and 60Co radioactive elements with photon energies of 0.662 MeV for 137Cs and two energy levels of 1.17 and 1.33 MeV for the 60Co. Likewise the mean free paths for the tested samples were obtained. The aim of this work is to investigate the effect of the waste loading rates and the particulate dispersive manner within the concrete matrix on the attenuation coefficients. The maximum linear attenuation coefficient (μ) was attained for concrete incorporates iron filling wastes of 30 wt %. They were of 1.12 ± 1.31×10-3 for 137Cs and 0.92 ± 1.57 × 10-3 for 60Co. Substantial improvement in attenuation performance by 20%-25% was achieved for concrete samples incorporate iron fillings as opposed to that of steel ball samples at different (5%-30%) loading rates. The steel balls and the steel slags gave much inferior values. The microstructure, concrete-metal composite density, the homogeneity and particulate dispersion were examined and evaluated using different metallographic, microscopic and measurement facilities.
  • Publication
    Identifying Real Estate Buyer's Feedback on Three-Dimensional Mock-Up Model Among House Buyers in Malaysia
    ( 2024-04-19)
    Fazdliel Aswad Ibrahim
    ;
    Hang Y.H.
    ;
    Shafiei M.W.M.
    ;
    Rafiza Abd Razak
    ;
    Nur Soleha Abdul Rahim
    ;
    Norsyakilah Romeli
    Marketing communications are intended to convey messages or information to target users. In today's competitive business environment, products and services companies need to make sure that the communications they use are effective as consumers are made up of many features that have different perspectives and feedback. However, there is almost no specific study in this regard that focuses on the housing sector. Therefore, the aim of this research is to study the real estate buyers' response towards the marketing communications process and the marketing communication channels which are used in the housing industry in marketing the real estate property. A set of survey questions will be used in conjunction with a three-dimensional mock-up housing model in collecting the response from the real estate buyers in Malaysia. The data collection will be conducted through social media platforms where the convenience of non-probability sampling method is used in this study to obtain the real estate buyer's feedback. This study uses a quantitative method of survey to collect the data. The study data will be analysed using SPSS (Statistical package for the social sciences) software. The expectation of this study is to support the research literature on marketing communications in general as well as the real estate sector, in addition to provide guidance for real estate developers to improve their marketing communications, thus protecting the social interests of home buyers.
  • Publication
    Study on polypropylene twisted bundle fiber reinforced lightweight foamed concrete
    ( 2023)
    Md Azree Othuman Mydin
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rafiza Abd Razak
    ;
    Mohd Nasrun Mohd Nawi
    ;
    Puput Risdanareni
    ;
    Poppy Puspitasari
    ;
    Andrei Victor Sandu
    ;
    Madalina Simona Baltatu
    ;
    Petrica Vizureanu
    Recent industrial developments have focused more and more on the applications of lightweight foamed concrete (LFC) in the construction industry, having advantages over normal-strength concrete. LFC, however, has several drawbacks including brittleness, high porosity, excessive drying shrinkage, rapid cracking, and low deformation resistance. Practical engineering typically chooses steel fiber or polymer fiber to increase the tensile and fracture resistance of LFC. The polypropylene twisted bundle fiber (PTBF) was added to the LFC with varying weight fractions of 0.0%, 0.5%, 1.0%, 1.5%, 2.0% and 2.5%. Three low densities of LFC were prepared, specifically 500 kg/m3, 700 kg/m3 and 900 kg/m3. The mechanical and durability properties of PTBF-reinforced LFC were determined through compression, flexural, splitting tensile, flow table, porosity, and water absorption tests. The results show that the addition of PTBF in LFC significantly improves the strength properties (compressive, flexural, and splitting tensile strengths) and reduces the water absorption capacity and porosity. The optimal weight fraction of PTBF was between 1.5 and 2.0% for mechanical properties enhancement. The inclusion of PTBF increased the ductility of LFC, and the specimens remain intact from loading to failure. The PTBF reduces the original cracks of the LFC and inhibits the development of further cracks in the LFC.
  • Publication
    Effect of Rice Straw Ash (RSA) as partially replacement of cement toward fire resistance of self-compacting concrete
    ( 2022)
    Yi Qin Chin
    ;
    Rafiza Abd Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Zarina Yahya
    ;
    Mokhzani Khair Ishak
    ;
    Sebastian Garus
    ;
    Marcin Nabiałek
    ;
    Warid Wazien Ahmad Zailani
    ;
    Khairil Azman Masri
    ;
    Andrei Victor Sandu
    ;
    Agata Śliwa
    Malaysia’s construction industry is experiencing rapid growth, translating into increased demand for cement. However, cement production pollutes the air to the detriment of the climate via CO2 emission, making research into a cementitious replacement in concrete a necessity. This paper details an experimental study of self-compacting concrete (SCC) with partial replacement of cement by rice straw ash (RSA), which is expected to result in environmental preservation due to the green materials being used in cement production. The physicomechanical properties of the SCC with RSA replacement were determined via its compressive strength, water absorption, self-workability, and fire resistance (residual strength after exposure to high temperatures). The proportion of RSA replacement used were 0%, 5%, 10%, 15%, 20%, and 25%, and all passed the slump flow test, except the 20% and 25% samples. The SCC samples with 15% of RSA replacement reported the highest compressive strength at 7 and 28 curing days and the highest residual strength post-exposure to high temperatures. The lowest percentage of water absorption was reported by the 15% of RSA replacement, with a density of 2370 kg/m3
  • Publication
    Setting time and after setting properties of high calcium fly ash geopolymers with different concentration of sodium hydroxide
    ( 2021)
    Rosnita Mohamed
    ;
    Rafiza Abd Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ikmal Hakem Aziz
    ;
    Liyana Ahmad Sofri
    ;
    Noor Fifinatasha Shahedan
    Setting time in geopolymers is known as the time taken for the transition phase of liquid to solid of the geopolymer system in which is represented in the initial setting and final setting. Setting time is significant specifically for application in the construction field. This study intends to determine the setting time of high calcium fly ash geopolymers and the properties of the geopolymers after setting (1-day age). This includes the determination of heat evolved throughout geopolymerization using Differential Scanning Calorimeter. After setting properties determination includes compressive strength and morphology analysis at 1-day age. High calcium fly ash was used as geopolymer precursor. Meanwhile, for mixing design, the alkali activator was a mixture of sodium silicate and sodium hydroxide (concentration varied from 6M-14M) with a ratio of 2.5 and a solid-to-liquid ratio of 2.5. From this study, it was found that high calcium fly ash geopolymer with 12M of NaOH has a reasonable setting time which is suitable for on-site application as well as an optimal heat evolved (–212 J/g) which leads to the highest compressive strength at 1-day age and no formation of microcracks observed on the morphology. Beyond 12M, too much heat evolved in the geopolymer system can cause micro-cracks formation thus lowering the compressive strength at 1-day age.
  • Publication
    A Review on the Concrete Durability Exposed to Different Wet-Dry Cycles Conditions
    ( 2024-04-19)
    Zarina Yahya
    ;
    Rafiza Abd Razak
    ;
    Khairunnisa Muhamad
    Concrete structure is prone to corrosion and weathering when built near marine environment. The greater damage on the concrete can be observed when it involves wet-dry action such as tidal waves combine with the existence of aggressive ions such as sulphate and chloride in seawater. The objective of this study is to review on the mechanism of sulphate, chloride attack toward concrete, parameters that influence the wet-dry action and identify the overview of research trends. The mechanism of sulphate and chloride attack during wet-dry action had reciprocal inhibiting effect on concrete and the penetration level for each ion also vary. The physical and mechanical damage of concrete exposed to wet-dry action also influence by wet-dry ratio, number of cycles and temperature during drying process. The main compound detected during exposure period are Friedel salt, ettringite, mirabilite and thenardite which can cause concrete delamination and spalling.
  • Publication
    Development of High Strength Alluvial Brick by Incorporative of Coconut Fibre
    ( 2024-04-19)
    Rafiza Abd Razak
    ;
    Sagaran R.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Zarina Yahya
    ;
    Junaidi S.
    ;
    Alida Abdullah
    The new properties of alluvial brick can be created by addition to the coconut fibre. An analysis on compressive strength and water absorption percentage of alluvial brick and coconut fibre alluvial brick are presented in this research. There are four main different operations are involved in the process of manufacturing of alluvial bricks such as preparation of alluvial clay and coconut fibre, moulding of bricks, pre-drying of bricks and burning of bricks at 500°C, 600°C and 700°C. The results showed that the alluvial soil brick (without coconut fibre) burnt at 600°C exhibits the highest compressive strength of 17.33MPa and water absorption rate is 5.56% after soaked 24 hours in water. By using 600°C as the optimum temperature, alluvial bricks incorporating of coconut fibre are burnt. The highest value of compressive strength of coconut fibre alluvial brick is 16.57MPa and the water absorption is 11.11%. The outcomes of this research proved that the pure alluvial soil brick which not mixed with any add mixtures can be used in the construction project and it can be considered as a new type of brick in construction material. The coconut fibre alluvial brick also has fulfil the requirements to contribute to sustainable development as coconut fibre alluvial brick is made use of waste coconut fibre that environmental friendly and at the same time, it could decreases the waste material disposal.
  • Publication
    A State-of-the-Art review on innovative geopolymer composites designed for water and wastewater treatment
    ( 2021)
    Ismail Luhar
    ;
    Salmabanu Luhar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rafiza Abd Razak
    ;
    Petrica Vizureanu
    ;
    Andrei Victor Sandu
    ;
    Petre-Daniel Matasaru
    There is nothing more fundamental than clean potable water for living beings next to air. On the other hand, wastewater management is cropping up as a challenging task day-by-day due to lots of new additions of novel pollutants as well as the development of infrastructures and regulations that could not maintain its pace with the burgeoning escalation of populace and urbanizations. Therefore, momentous approaches must be sought-after to reclaim fresh water from wastewaters in order to address this great societal challenge. One of the routes is to clean wastewater through treatment processes using diverse adsorbents. However, most of them are unsustainable and quite costly e.g. activated carbon adsorbents, etc. Quite recently, innovative, sustainable, durable, affordable, user and eco-benevolent Geopolymer composites have been brought into play to serve the purpose as a pretty novel subject matter since they can be manufactured by a simple process of Geopolymerization at low temperature, lower energy with mitigated carbon footprints and marvellously, exhibit outstanding properties of physical and chemical stability, ion-exchange, dielectric characteristics, etc., with a porous structure and of course lucrative too because of the incorporation of wastes with them, which is in harmony with the goal to transit from linear to circular economy, i.e., “one’s waste is the treasure for another”. For these reasons, nowadays, this ground-breaking inorganic class of amorphous alumina-silicate materials are drawing the attention of the world researchers for designing them as adsorbents for water and wastewater treatment where the chemical nature and structure of the materials have a great impact on their adsorption competence. The aim of the current most recent state-of-the-art and scientometric review is to comprehend and assess thoroughly the advancements in geo-synthesis, properties and applications of geopolymer composites designed for the elimination of hazardous contaminants viz., heavy metal ions, dyes, etc. The adsorption mechanisms and effects of various environmental conditions on adsorption efficiency are also taken into account for review of the importance of Geopolymers as most recent adsorbents to get rid of the death-defying and toxic pollutants from wastewater with a view to obtaining reclaimed potable and sparkling water for reuse offering to trim down the massive crisis of scarcity of water promoting sustainable water and wastewater treatment for greener environments. The appraisal is made on the performance estimation of Geopolymers for water and wastewater treatment along with the three-dimensional printed components are characterized for mechanical, physical and chemical attributes, permeability and Ammonium (NH4+) ion removal competence of Geopolymer composites as alternative adsorbents for sequestration of an assortment of contaminants during wastewater treatment.
  • Publication
    Geopolymer-based artificial aggregates: a review on methods of producing, properties, and improving techniques
    ( 2022)
    Mohammad Almadani
    ;
    Rafiza Abd Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Rosnita Mohamed
    The depletion of aggregate-related natural resources is the primary concern of all researchers globally. Recent studies emphasize the significance of recycling and reusing various types of natural or by-product material waste from industry as a result of the building industry’s rising demand for aggregate as the primary component in concrete production. It has been demonstrated that the geopolymer system has exceptional features, such as high strength, superior durability, and greater resistance to fire exposure, making it a viable alternative to ordinary Portland Cement (OPC) concrete. This study will examine the present method utilized to generate artificial aggregate-based geopolymers, including their physical and mechanical properties, as well as their characterization. The production process of geopolymer derived from synthetic aggregates will be highlighted. In conjunction with the bonding of aggregates and the cement matrix, the interfacial transition zone (ITZ) is highlighted in this work as an additional important property to be researched in the future. It will be discussed how to improve the properties of geopolymers based on artificial aggregates. It has been demonstrated that cold bonding provides superior qualities for artificial aggregate while conserving energy during production. The creation of ITZ has a significant impact on the bonding strength between artificial aggregates and the cement matrix. Additionally, improvement strategies demonstrate viable methods for enhancing the quality of manufactured aggregates. In addition, other recommendations are discussed in this study for future work.