Now showing 1 - 10 of 34
  • Publication
    Study on the effects of anodizing voltage to the AAO thin film dimensional properties synthesized by single step anodization method
    Anodic aluminium oxide (AAO) thin film electrodes were synthesized by using a single step anodizing method in 15 °C of 0.3 M oxalic acid at five different anodizing voltage ranging from 20 V to 60 V, respectively. The effect of anodizing voltage to the AAO dimensional properties were about to be investigated. Morphological observations were all done by FESEM where the measurements and calculation were made by using ImageJ and formulas. To ensure that the pore sizes were totally depended on the anodizing voltage, etching process were done at constant duration for all samples. The correlation between all AAO dimensional properties like pores size, interpore distance, wall thickness, pore density, percentage of porosity and nanoporous oxide thickness were presented in a linear graph.
  • Publication
    Effect of different NaOH molarity towards fly ash based geopolymer for underwater concreting
    ( 2020-11-02)
    Zaidi F.H.A.
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    Ghazali C.M.R.
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    ; ; ;
    Syauqi A.
    In current industry, underwater concrete is one of the special type of high performance concrete in which it can perform well at least in strength, workability, service life and probably have a bright future as long as there is a need to construct bridges. With sufficient attention to concrete mix design and placement technique, the underwater concrete casting can be successfully implemented. Thus, this paper investigates the effect of different sodium hydroxide molarity towards the strength of fly ash based geopolymer for underwater concreting.
      3  12
  • Publication
    Bahan geopolimer : Pemprosesan, Pencirian dan Aplikasi
    Buku Bahan Geopolimer: Pemprosesan, Pencirian dan Aplikasi adalah sebuah buku yang membincangkan beberapa aspek penting mengenai bahan geopolimer seperti pemprosesan, perincian, aplikasi dan sifat bahan geopolimer dalam teknologi konkrit. Buku ini juga menerangkan secara terperinci tentang bahan geopolimer dari aspek teori, pemprosesan, pencirian dan aplikasi yang sesuai dijadikan sebagai bahan rujukan dan panduan kepada pelajar, penyelidik dan pengamal industri.
      7  205
  • Publication
    Compressive strength and thermal conductivity of metakaolin geopolymers with anisotropic insulations
    This research investigated the properties of thermally insulating geopolymer prepared using waste filler (fibreboard and rubber) to act as anisotropic pore/insulation. The geopolymer matrix was synthesised using metakaolin and an alkaline solution consists of sodium hydroxide solution and sodium silicate mixture. Geopolymers with varying content (0, 3, 5 and 7 layers) of coin-shaped fibreboard and expanded polystyrene are produced to examine the anisotropic insulation effect on the material characteristics. The compressive strength and thermal conductivity were determined experimentally. From the results, it is proved that the use of anisotropic insulations can improve the thermal conductivity and minimizing the reduction of compressive strength. Geopolymer incorporated with fibreboard had better performance in terms of strength while geopolymer incorporated with rubber had better thermal conductivity.
      3  25
  • Publication
    Evaluation on the mechanical properties of Ground Granulated Blast Slag (GGBS) and fly ash stabilized soil via geopolymer process
    ( 2021)
    Syafiadi Rizki Abdila
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    ; ; ;
    Małgorzata Rychta
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    Izabela Wnuk
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    Marcin Nabiałek
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    Krzysztof Muskalski
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    Muhammad Syafwandi
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    Marek Isradi
    This study intended to address the problem of damaged (collapsed, cracked and decreased soil strength) road pavement structure built on clay soil due to clay soil properties such as low shear strength, high soil compressibility, low soil permeability, low soil strength, and high soil plasticity. Previous research reported that ground granulated blast slag (GGBS) and fly ash can be used for clay soil stabilizations, but the results of past research indicate that the road pavement construction standards remained unfulfilled, especially in terms of clay’s subgrade soil. Due to this reason, this study is carried out to further investigate soil stabilization using GGBS and fly ash-based geopolymer processes. This study investigates the effects of GGBS and ratios of fly ash (solid) to alkaline activator (liquid) of 1:1, 1.5:1, 2:1, 2.5:1, and 3:1, cured for 1 and 7 days. The molarity of sodium hydroxide (NaOH) and the ratio of sodium silicate (Na2SiO3) to sodium hydroxide (NaOH) was fixed at 10 molar and 2.0 weight ratio. The mechanical properties of the soil stabilization based geopolymer process were tested using an unconfined compression test, while the characterization of soil stabilization was investigated using the plastic limit test, liquid limit test, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that the highest strength obtained was 3.15 MPA with a GGBS to alkaline activator ratio of 1.5 and Na2SiO3 to NaOH ratio of 2.0 at 7 days curing time. These findings are useful in enhancing knowledge in the field of soil stabilization-based geopolymer, especially for applications in pavement construction. In addition, it can be used as a reference for academicians, civil engineers, and geotechnical engineers.
      8  22
  • Publication
    Structural and mechanical characterisation of cellulose nanofibers (CNF) from Pennisetum Purpureum reinforced with polylactic acid (PLA)
    This study aims to develop a composite scaffold based on polylactic acid reinforced with cellulose nanofibers from Pennisetum purpureum (PLA/CNF). The composite scaffolds were prepared via solvent casting and particulate leaching technique; sodium chloride (NaCl) was used as the porogen material. The influence of CNF on PLA is investigated; scaffolds were fabricated with different content of CNF (5%, 10% and 15%). The prepared composite scaffold was characterised using porosity measurements, Fourier-transform infrared spectroscopy (FTIR) and the compression strength and modulus were also evaluated in this study. The PLA/CNF scaffolds were highly porous with porosity higher than 80%. It was also shown that the porosity had a slight decrease with increasing CNF contents due to the compact arrangement of CNF within the scaffolds. Compression strength and modulus also show an increase in value as the CNF content increases. The results also show that introducing CNF to the PLA matrix can be considered beneficial for cartilage regeneration, cell attachment, and extracellular matrix (ECM) production.
      3  24
  • Publication
    Mechanical and durability analysis of fly ash based geopolymer with various compositions for rigid pavement applications
    ( 2022) ; ; ;
    Mohd Rosli Mohd Hasan
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    Andrei Victor Sandu
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    Petrica Vizureanu
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    Che Mohd Ruzaidi Ghazali
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    Aeslina Abdul Kadir
    Ordinary Portland cement (OPC) is a conventional material used to construct rigid pavement that emits large amounts of carbon dioxide (CO2) during its manufacturing process, which is bad for the environment. It is also claimed that OPC is susceptible to acid attack, which increases the maintenance cost of rigid pavement. Therefore, a fly ash based geopolymer is proposed as a material for rigid pavement application as it releases lesser amounts of CO2 during the synthesis process and has higher acid resistance compared to OPC. This current study optimizes the formulation to produce fly ash based geopolymer with the highest compressive strength. In addition, the durability of fly ash based geopolymer concrete and OPC concrete in an acidic environment is also determined and compared. The results show that the optimum value of sodium hydroxide concentration, the ratio of sodium silicate to sodium hydroxide, and the ratio of solid-to-liquid for fly ash based geopolymer are 10 M, 2.0, and 2.5, respectively, with a maximum compressive strength of 47 MPa. The results also highlight that the durability of fly ash based geopolymer is higher than that of OPC concrete, indicating that fly ash based geopolymer is a better material for rigid pavement applications, with a percentage of compressive strength loss of 7.38% to 21.94% for OPC concrete. This current study contributes to the field of knowledge by providing a reference for future development of fly ash based geopolymer for rigid pavement applications.
      21  2
  • Publication
    Correlation between Thermal Insulation Properties with Compressive Strength and Density of Lightweight Geopolymer
    This paper reports the results of an experimental work conducted to investigate the correlation between thermal insulation properties with compressive strength and density of lightweight geopolymer prepared by using fly ash as source material and combination of sodium hydroxide and sodium silicate as alkaline activator. The experiments were conducted by varying the ageing time of 3, 7, 28, 60 and 90 days, respectively. The specimens cured for a period of 90 days have presented the highest compressive strength and lowest density accompanied with satisfied value of thermal conductivity. From the results obtained, it was evident that the thermal conductivity had a high correlation coefficient with compressive strength and density.
      2  22
  • Publication
    Experimental investigation of chopped steel wool fiber at various ratio reinforced cementitious composite panels
    The flexural toughness of chopped steel wool fiber reinforced cementitious composite panels was investigated. Reinforced cementitious composite panels were produced by mixing of chopped steel wool fiber with a ratio range between 0.5% to 6.0% and 0.5% as a step increment of the total mixture weight, where the cement to sand ratio was 1:1.5 with water to cement ratio of 0.45. The generated reinforced cementitious panels were tested at 28 days in terms of load-carrying capacity, deflection capacities, post-yielding effects, and flexural toughness. The inclusion of chopped steel wool fiber until 4.5% resulted in gradually increasing load-carrying capacity and deflection capacities while, provides various ductility, which would simultaneously the varying of deflection capability in the post-yielding stage. Meanwhile, additional fiber beyond 4.5% resulted in decreased maximum load-carrying capacity and increase stiffness at the expense of ductility. Lastly, the inclusion of curves gradually.
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