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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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1 - 10 of 11
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PublicationArtificial lightweight aggregates made from pozzolanic material: A review on the method, physical and mechanical properties, thermal and microstructure( 2022)
;Dickson Ling Chuan Hao ;Marwan Kheimi ;Dumitru Doru Burduhos Nergis ;Hamzah Fansuri ;Ratna Ediati ;Rosnita MohamedAs the demand for nonrenewable natural resources, such as aggregate, is increasing worldwide, new production of artificial aggregate should be developed. Artificial lightweight aggregate can bring advantages to the construction field due to its lower density, thus reducing the dead load applied to the structural elements. In addition, application of artificial lightweight aggregate in lightweight concrete will produce lower thermal conductivity. However, the production of artificial lightweight aggregate is still limited. Production of artificial lightweight aggregate incorporating waste materials or pozzolanic materials is advantageous and beneficial in terms of being environmentally friendly, as well as lowering carbon dioxide emissions. Moreover, additives, such as geopolymer, have been introduced as one of the alternative construction materials that have been proven to have excellent properties. Thus, this paper will review the production of artificial lightweight aggregate through various methods, including sintering, cold bonding, and autoclaving. The significant properties of artificial lightweight aggregate, including physical and mechanical properties, such as water absorption, crushing strength, and impact value, are reviewed. The properties of concrete, including thermal properties, that utilized artificial lightweight aggregate were also briefly reviewed to highlight the advantages of artificial lightweight aggregate. -
PublicationDevelopment of High Strength Alluvial Brick by Incorporative of Coconut Fibre( 2024-04-19)
;Sagaran R. ;Junaidi S.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. -
PublicationMechanical performance, microstructure, and porosity evolution of fly ash geopolymer after ten years of curing age( 2023)
;Ikmal Hakem A. Aziz ;Jitrin Chaiprapa ;Catleya Rojviriya ;Petrica Vizureanu ;Andrei Victor SanduThis paper elucidates the mechanical performance, microstructure, and porosity evolution of fly ash geopolymer after 10 years of curing age. Given their wide range of applications, understanding the microstructure of geopolymers is critical for their long-term use. The outcome of fly ash geopolymer on mechanical performance and microstructural characteristics was compared between 28 days of curing (FA28D) and after 10 years of curing age (FA10Y) at similar mixing designs. The results of this work reveal that the FA10Y has a beneficial effect on strength development and denser microstructure compared to FA28D. The total porosity of FA10Y was also lower than FA28D due to the anorthite formation resulting in the compacted matrix. After 10 years of curing age, the 3D pore distribution showed a considerable decrease in the range of 5–30 µm with the formation of isolated and intergranular holes. -
PublicationProperties and morphology of fly ash based Alkali Activated Material (AAM) paste under steam curing condition( 2022)
;Sh. Nur Syamimi Sy. IzmanRosnita MohamedThis paper details the properties, microstructures, and morphologies of the fly ash-based alkali-activated material (AAM), also known as geopolymers, under various steam curing temperatures. The steam curing temperature result in subsequent high strengths relative to average curing temperatures. However, detailed studies involving the use of steam curing for AAM remain scarce. The AAM paste was prepared by mixing fly ash with an alkali activator consisting of sodium silicate (Na2SiO3) and sodium hydroxide (NaOH). The sample was steam cured at 50°C, 60°C, 70°C, and 80°C, and the fresh paste was tested for its setting time. The sample also prepared for compressive strength, density, and water absorption testings. It was observed that the fastest time for the fly ash geopolymer to start hardening was at 80°C at only 10 minutes due to the elevated temperature quickening the hydration of the paste. The compressive strength of the AAM increased with increasing curing time from 3 days to 28 days. The AAM’s highest compressive strength was 61 MPa when the sample was steam cured at 50°C for 28 days. The density of AAM was determined to be ~2122 2187 kg/m3 , while its water absorption was ~6.72-8.82%. The phase analyses showed the presence of quartz, srebrodolskite, fayalite, and hematite, which indirectly confirms Fe and Ca’s role in the hydration of AAM. The morphology of AAM steam-cured at 50°C showed small amounts of unreacted fly ash and a denser matrix, which resulted in high compressive strength. -
PublicationArticle the effects of various concentrations of naoh on the inter-particle gelation of a fly ash geopolymer aggregate( 2021-03-01)
;Sochacki W. ;Błoch K.Fansuri H.Aggregates can be categorized into natural and artificial aggregates. Preserving natural resources is crucial to ensuring the constant supply of natural aggregates. In order to preserve these natural resources, the production of artificial aggregates is beginning to gain the attention of researchers worldwide. One of the methods involves using geopolymer technology. On this basis, this current research focuses on the inter-particle effect on the properties of fly ash geopolymer aggregates with different molarities of sodium hydroxide (NaOH). The effects of synthesis parameters (6, 8, 10, 12, and 14 M) on the mechanical and microstructural properties of the fly ash geopolymer aggregate were studied. The fly ash geopolymer aggregate was palletized manually by using a hand to form a sphere-shaped aggregate where the ratio of NaOH/Na2SiO3 used was constant at 2.5. The results indicated that the NaOH molarity has a significant effect on the impact strength of a fly ash geopolymer aggregate. The highest aggregate impact value (AIV) was obtained for samples with 6 M NaOH molarity (26.95%), indicating the lowest strength among other molarities studied and the lowest density of 2150 kg/m3 . The low concentration of sodium hydroxide in the alkali activator solution resulted in the dissolution of fly ash being limited; thus, the inter-particle volume cannot be fully filled by the precipitated gels.1 -
PublicationPerformance of Sintered Pozzolanic Artificial Aggregates as Coarse Aggregate Replacement in Concrete( 2021-01-01)
;Subaer ;Mohamed R.The abundant increase in waste quantities year by year and the depletion of natural resources worldwide are the major concerns among researchers. Recycling and reusing various types of natural or by-product material waste from industry become highlighted in the recent study. The growing demand for concrete and the production of artificial aggregate become crucial in the construction industry. Artificial aggregate can be produced either by sintering, auto-clave or cold bonding method. Although auto-clave and cold bonding methods can minimize energy consumption, the selection of the sintering method always leads to high quality and better properties of artificial aggregates produced. The use of sintering methods to produce artificial aggregate made from pozzolanic material focuses on the use of volcanic ash as raw material activated by geopolymerization process to produce artificial lightweight aggregate-based geopolymer will be summarized in this chapter. This chapter discusses the result of the physical and mechanical properties of artificial lightweight aggregate or known as sintered geopolymer volcanic ash artificial lightweight aggregate (SGVA). The interfacial transition zone (ITZ) of sintered geopolymer volcanic ash artificial lightweight aggregate (SGVA) is presented. The performance of sintered geopolymer volcanic ash artificial lightweight aggregate (SGVA) in concrete is also discussed.1 -
PublicationFeasibility of treated sand brick waste with silica fume based geopolymer for coarse aggregate application( 2024-01-01)
;Kiong A.N.D. ;Mydin A.O. ;Sandu A.V. ;Risdanareni P.Arifi E.Construction and demolition waste (CDW) management should focus on reducing CDW or properly recycling the materials since this waste is now a global problem. Sand brick waste, a component of a building’s structure, is one type of CDW. To be used as recycled aggregate, these wastes are invariably categorised as low grade. Due of the improved qualities provided, geopolymer research has recently become more popular. The objective of this study is to investigate the physical and mechanical properties of recycled sand brick aggregate (RSB) treated with silica fume based geopolymer coating. Additionally, the effectiveness of the treated RSB will be applied in concrete as coarse aggregate. The sample was made using a solid-to-liquid ratio of 1.0, 1.2, 1.4, 1.6, and 1.8. At 2.5 and 10 M, alkaline activator is a constant variable. Testing of specific gravity, water absorption, and aggregate impact value were analysed. The treated RSB concrete will then be evaluated against normal concrete. In terms of density, water absorption, and compressive strength, natural concrete performs better than treated RSB concrete. In comparison to natural concrete, treated RSB concrete absorbs 5.8% more water. Treated RSB concrete has a density of 1815 kg/m3, compared to natural concrete’s 2080 kg/m3. The compressive strength of concrete made using treated RSB aggregate is 18.1 MPa after 7 days, and 27.1 MPa at 28 days. The testing revealed that the treated RSB aggregate concrete met the specifications. As a result, treated RSB aggregate concrete offers an advantage over natural OPC concrete while saving the environment.2 -
PublicationGeopolymer coating paste on concrete for photocatalytic performance( 2021-05-03)
;Kusbiantoro A.Sandu A.V.Construction materials mainly used Portland cement as raw materials mainly caused global warming effect around the world. This article report a review on a research work carried out on the use of geopolymer coating on the concrete surface with catalyst for a good adsorption and efficiency via photocatalytic activity using sunlight. The geopolymer paste deposited by coating on the concrete or other building construction surface. The geopolymer paste were prepared by mixing aluminosilicates material with alkaline activator added with catalyst materials such as titanium dioxide and zinc oxide. The performance of geopolymer coating in removal of dyes reported comparable with other materials. Photocatalytic activity performance evaluate by adsorption of dyes onto geopolymer.1 -
PublicationAggregate impact value (AIV) of fly ash geopolymer artificial aggregate at different sodium hydroxide (NaOH) concentration( 2020-11-02)This research was conducted to study the aggregate impact value (AIV) of fly ash geopolymer artificial aggregate at different sodium hydroxide (NaOH) concentration. This research involves five different concentrations of NaOH solution which are 6M, 8M, 10M, 12M and 14M while ratio of NaOH/NaSi2O3 is constant at 2.5. In this study, the ratio of solid to liquid is fix at 3.0. The characterization of fly ash was observed by Scanning Electron Microscope (SEM). Results show that, the sample with 12M of NaOH concentration give the lowest percentage of AIV (22.43%) which denotes a high performance of aggregate in concrete field and also contribute to high performance of concrete while 6M of NaOH concentration gives the highest percentage of AIV (26.95%). The tested results indicated that the significant potential of fly ash geopolymer aggregate as an alternative artificial aggregate in construction materials field.
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PublicationMechanical Performance, Microstructure, and Porosity Evolution of Fly Ash Geopolymer after Ten Years of Curing Age( 2023-02-01)
;Aziz I.H.A. ;Chaiprapa J. ;Rojviriya C. ;Vizureanu P. ;Sandu A.V.This paper elucidates the mechanical performance, microstructure, and porosity evolution of fly ash geopolymer after 10 years of curing age. Given their wide range of applications, understanding the microstructure of geopolymers is critical for their long-term use. The outcome of fly ash geopolymer on mechanical performance and microstructural characteristics was compared between 28 days of curing (FA28D) and after 10 years of curing age (FA10Y) at similar mixing designs. The results of this work reveal that the FA10Y has a beneficial effect on strength development and denser microstructure compared to FA28D. The total porosity of FA10Y was also lower than FA28D due to the anorthite formation resulting in the compacted matrix. After 10 years of curing age, the 3D pore distribution showed a considerable decrease in the range of 5–30 µm with the formation of isolated and intergranular holes.1