Zarina Yahya
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Preferred name
Zarina Yahya
Official Name
Zarina, Yahya
Alternative Name
Yahya, Zarina
Zarina, Y.
Zarina, Yahya
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Scopus Author ID
51162069600
Researcher ID
DXZ-6436-2022

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  • Publication
    Rice husk (RH) as additive in fly ash based geopolymer mortar
    ( 2017-09-26)
    Zarina Yahya
    ;
    Rafiza Abd Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Mohd Azrin Adzhar Rahim
    ;
    Armia Nasri
    In recent year, the Ordinary Portland Cement (OPC) concrete is vastly used as main binder in construction industry which lead to depletion of natural resources in order to manufacture large amount of OPC. Nevertheless, with the introduction of geopolymer as an alternative binder which is more environmental friendly due to less emission of carbon dioxide (CO2) and utilized waste materials can overcome the problems. Rice husk (RH) is an agricultural residue which can be found easily in large quantity due to production of paddy in Malaysia and it's usually disposed in landfill. This paper investigated the effect of rice husk (RH) content on the strength development of fly ash based geopolymer mortar. The fly ash is replaced with RH by 0%, 5%, 10%, 15% and 20% where the sodium silicate and sodium hydroxide was used as alkaline activator. A total of 45 cubes were casted and their compressive strength, density and water absorption were evaluated at 1, 3, and 7 days. The result showed compressive strength decreased when the percentage of RH increased. At 5% replacement of RH, the maximum strength of 17.1MPa was recorded at day 7. The geopolymer has lowest rate of water absorption (1.69%) at 20% replacement of RH. The density of the sample can be classified as lightweight geopolymer concrete.
  • Publication
    Durability of geopolymer lightweight concrete infilled LECA in seawater exposure
    ( 2017-11-23)
    Rafiza Abd Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Zarina Yahya
    ;
    Hamid M.
    This paper describes a development of lightweight concrete using lightweight expanded clay aggregate (LECA) in fly ash (FA) based geopolymer immersed in seawater. The objective of this research is to compare the performance of geopolymer concrete (GPC) with ordinary Portland cement (OPC) concrete infilled lightweight expanded clay aggregate (LECA) in seawater exposure. Geopolymer concrete is produced by using alkaline activator to activate the raw material, FA. The highest compressive strength of this study is 42.0 MPa at 28 days and 49.8 MPa at 60 days. The density for this concrete is in the range of 1580 kg/m3 to 1660 kg/m3. The result for water absorption is in the range of 6.82% to 14.72%. However, the test results of weight loss is in the range between 0.30% to 0.43%.
  • Publication
    Surface resistivity and ultrasonic pulse velocity evaluation of reinforced opc concrete and reinforced geopolymer concrete in marine environment
    ( 2021-01-01)
    Mohd Badrul Hisyam Ab Manaf
    ;
    Zarina Yahya
    ;
    Rafiza Abd Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ariffin N.F.
    ;
    Muhammad Munsif Ahmad
    ;
    Chong Y.C.
    The concrete structures that are built along the seaside often suffer from reduced service life due to inadequate durability against deterioration. This research reports the findings of concrete resistivity and quality using two Non-Destructive Testing (NDT) measures applied to Reinforced Geopolymer and Ordinary Portland Cement (OPC) concrete in the marine environment. In addition, the relationship between Reinforced Geopolymer and Reinforced OPC concrete was statistically discussed in-terms of strength and direction. The testing was carried out using a Proceeq Resipod Wenner 4-probe to measure Surface Resistivity (SR) and Ultrasonic Pulse Velocity (UPV), respectively. The testings were carried out on beam shaped samples of OPC and Geopolymer concrete that were immersed in seawater over a period of 90 days with similar curing condition. It was found from the present investigation that the maximum SR and maximum UPV values acquired for both the Reinforced OPC and Reinforced Geopolymer concrete are 2.73 kΩcm and 2.07 kΩcm, as well as 4.18 km/s and 4.05 km/s, respectively. It is apparent from the study that both concrete is comparable in terms of quality and surface resistivity.
      1
  • 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
    The ProPerTies of Ground GranulaTed BlasT furnace slaG liGhTweiGhT aGGreGaTe (Gla) aT Various Molar raTio and iTs aPPlicaTion in concreTe
    ( 2023-01-01)
    Rafiza Abd Razak
    ;
    Hassan M.A.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Zarina Yahya
    ;
    Ariffin M.A.M.
    ;
    Ahmad Faizal Mansor
    ;
    Hao D.L.C.
    The effects of supplementary cementitious materials (SCM) on the characteristics and internal structure of synthetic aggregate made from ground granulated blast furnace slag are investigated in this study (GGBS). Due to its high pozzolanic activity, GGBS was shown to be superior to other SCM materials, enhancing both the strength and durability of synthetic aggregate. Because sintering uses a lot of energy and generates a lot of pollutants, using a cold-bonded approach to make low density lightweight aggregates is particularly significant from an economic and environmental standpoint. Thus, the utilisation of ground granulated blast furnace slag (GGBS) as a substitute material in the production of green artificial lightweight aggregate (GLA) using the cold bonding method was discussed in this work. Admixtures of ADVA Cast 203 and Hydrogen Peroxide were utilised to improve the quality of GLA at various molar ratios. The freshly extracted GLA was then evaluated for specific gravity, water absorption, aggregate impact, and aggregate crushing in order to determine the optimal proportion blend. As a result, the overall findings offer great application potential in the development of concrete (GCLA). It has been determined that aggregates with a toughness of 14.6% and a hardness of 15.9% are robust. The compressive strength test found that the GCLA has a high strength lightweight concrete of 37.19 MPa and a density of 1845.74 kg/m3. The porous features developed inside the internal structure of GLA have led to GCLA’s less weight compared to conventional concrete.
      2
  • Publication
    Comparative study on early strength of sodium hydroxide (NaOH) activated fly ash based geopolymer
    ( 2017-09-29)
    Zarina Yahya
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Siti Zulaikha Abd Talib
    ;
    Rafiza Abd Razak
    The urge to reduce carbon dioxide (CO2) emission has encourage researchers to introduce environmental friendly binder or known as geopolymer. This new binder was produced by mixing source materials rich in silica and alumina with alkaline liquids. For this study, class F fly ash was used as source material with two different types of alkaline activator; sodium hydroxide (NaOH) only and a combination of water glass with NaOH. The different concentration of the NaOH solutions (8M, 10M, 12M and 14M) is used in the production of geopolymer. The parameters such as curing regime, solid/liquid ratio, and water glass/NaOH ratio are controlled in the study. The samples with combination of NaOH and water glass as alkaline activator were prepared by mixing these two solution and stirred for 2 minutes. Then this solution were mixed together with fly ash for 3 minutes and casted in the mould. The performance of the fly ash based geopolymer are evaluated by the compressive strength, water absorption and density at the early age of 1th, 3th and 7th days. Based on the study, at a concentration of 14M on 7th days had achieved the maximum compressive strength of 7.1 MPa for samples activated with NaOH only. Meanwhile, for geopolymer samples activated with a combination of the water glass and NaOH, the maximum strength of 33.33 MPa was recorded on 7th days of testing with NaOH concentration of 12 M. The water absorption for all geopolymer samples were ranging from 2.04 % to 2.78%, which are below the limit (3%). While the density of the geopolymer paste were in the range of 1552 kg/m3 to 1680 kg/m3, which are below the limit (2400 kg/m3). From the standpoint of strength of hardened geopolymer samples, the most effective alkaline activator in geopolymer is the combination of NaOH and water glass.
      3  23
  • Publication
    Effect of Rice Straw Ash (RSA) as partially replacement of cement toward fire resistance of self-compacting concrete
    (Polska Akademia Nauk, 2022-01-01)
    Rafiza Abd Razak
    ;
    Chin Y.Q.
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Zarina Yahya
    ;
    Mokhzani Khair Ishak
    ;
    Garus S.
    ;
    Nabiałek M.
    ;
    Zailani W.W.A.
    ;
    Masri K.A.
    ;
    Sandu A.V.
    ;
    Åšliwa A.
    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.
      4  26
  • Publication
    Geopolymer coating paste on concrete for photocatalytic performance
    ( 2021-05-03)
    Liyana Jamaludin
    ;
    Rafiza Abd Razak
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Kusbiantoro A.
    ;
    Zarina Yahya
    ;
    Alida Abdullah
    ;
    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
  • Publication
    The effect Na2SiO3/NaOH ratio to specific gravity and water absorption of artifiticial geopolymer aggregate dolomite based
    ( 2017-09-26)
    Aiman Mahmad Nor
    ;
    Zarina Yahya
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Industry such as construction and materials had depended a lot on the available aggregate. The use of aggregate need to be designed so that it have a well sustainable system with good physical properties. This paper is using dolomite to produce an artificial aggregate. The dolomite based artificial aggregate is produced using geopolymer as a hardened process. The dolomite base artificial aggregate is tested with a different alkaline activator to find water absorption and density. The lowest water absorption of dolomite artificial aggregate is 14%. The specific gravity of the artificial aggregate tested are lower when the sodium silicate is decreasing. The lowest density of artificial aggregate obtain are with 2.03 g/cm3.
      12  2
  • Publication
    Aggregate impact value (AIV) of fly ash geopolymer artificial aggregate at different sodium hydroxide (NaOH) concentration
    ( 2020-11-02)
    Alida Abdullah
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Kamarudin Hussin
    ;
    Zarina Yahya
    ;
    Romisuhani Ahmad
    ;
    Rafiza Abd Razak
    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.
      1