Now showing 1 - 10 of 422
  • Publication
    Finite element analysis on structural behaviour of geopolymer reinforced concrete beam using Johnson-Cook damage in Abaqus
    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
    Kaolin-based geopolymer as a heavy metal removal: Short review
    ( 2023)
    Ikmal Hakem AZIZ
    ;
    Nurul Ain MAZLAN
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    ;
    Noor Fifinatasha SHAHEDAN
    ;
    Ratna EDIATI
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    ;
    Hamzah FANSURI
    Adsorption procedure have been studies and found to be an effective, easy, and low-cost approach for removing heavy metals from aqueous solution when compared to other methods and technologies. Porous geopolymer will be made by combining aluminosilicate mineral with an alkaline activation solution to be utilized as an adsorbent. This review focuses on the current development in heavy metal removal material. This work also summarize the crucial factors (such as solid-to-liquid ratio, foaming agent ratio, sintering temperatures, and adsorbent dosage) influenced the properties (pore formation, microstructure, chemical bonding, and phase analysis) of kaolin-based geopolymer were highlighted. This review manifests the remarkable potential of kaolin-based geopolymer in high-added value applications.
  • Publication
    Fly Ash porous material using geopolymerization process for high temperature exposure
    ( 2012-04-10) ; ; ;
    Mohamed Bnhussain
    ;
    Che Mohd Ruzaidi Ghazali
    ;
    Mohd Izzat Ahmad
    This paper presents the results of a study on the effect of temperature on geopolymers manufactured using pozzolanic materials (fly ash). In this paper, we report on our investigation of the performance of porous geopolymers made with fly ash after exposure to temperatures from 600 °C up to 1000 °C. The research methodology consisted of pozzolanic materials (fly ash) synthesized with a mixture of sodium hydroxide and sodium silicate solution as an alkaline activator. Foaming agent solution was added to geopolymer paste. The geopolymer paste samples were cured at 60 °C for one day and the geopolymers samples were sintered from 600 °C to 1000 °C to evaluate strength loss due to thermal damage. We also studied their phase formation and microstructure. The heated geopolymers samples were tested by compressive strength after three days. The results showed that the porous geopolymers exhibited strength increases after temperature exposure.
  • Publication
    Use of calcium carbonate nanoparticles in production of nano-engineered foamed concrete
    ( 2023)
    Md Azree Othuman Mydin
    ;
    P. Jagadesh
    ;
    Alireza Bahrami
    ;
    Anmar Dulaimi
    ;
    Yasin Onuralp Özkılıç
    ;
    ;
    Ramadhansyah Putra Jaya
  • Publication
    Comparison of hook and straight steel fibers addition on malaysian fly ash-based geopolymer concrete on the slump, density, water absorption and mechanical properties
    ( 2021) ; ;
    Ratnasamy Muniandy
    ;
    ;
    Katarzyna Błoch
    ;
    Bartłomiej Jeż
    ;
    Sebastian Garus
    ;
    Paweł Palutkiewicz
    ;
    ;
    Geopolymer concrete has the potential to replace ordinary Portland cement which can reduce carbon dioxide emission to the environment. The addition of different amounts of steel fibers, as well as different types of end-shape fibers, could alter the performance of geopolymer concrete. The source of aluminosilicate (fly ash) used in the production of geopolymer concrete may lead to a different result. This study focuses on the comparison between Malaysian fly ash geopolymer concrete with the addition of hooked steel fibers and geopolymer concrete with the addition of straight-end steel fibers to the physical and mechanical properties. Malaysian fly ash was first characterized by X-ray fluorescence (XRF) to identify the chemical composition. The sample of steel fiber reinforced geopolymer concrete was produced by mixing fly ash, alkali activators, aggregates, and specific amounts of hook or straight steel fibers. The steel fibers addition for both types of fibers are 0%, 0.5%, 1.0%, 1.5%, and 2.0% by volume percentage. The samples were cured at room temperature. The physical properties (slump, density, and water absorption) of reinforced geopolymer concrete were studied. Meanwhile, a mechanical performance which is compressive, as well as the flexural strength was studied. The results show that the pattern in physical properties of geopolymer concrete for both types of fibers addition is almost similar where the slump is decreased with density and water absorption is increased with the increasing amount of fibers addition. However, the addition of hook steel fiber to the geopolymer concrete produced a lower slump than the addition of straight steel fibers. Meanwhile, the addition of hook steel fiber to the geopolymer concrete shows a higher density and water absorption compared to the sample with the addition of straight steel fibers. However, the difference is not significant. Besides, samples with the addition of hook steel fibers give better performance for compressive and flexural strength compared to the samples with the addition of straight steel fibers where the highest is at 1.0% of fibers addition.
  • Publication
    Thermal insulation properties of insulated concrete
    ( 2019-01-01)
    Shahedan N.F.
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    ; ;
    Kusbiantoro A.
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    ;
    Sandu A.V.
    ;
    Naveed A.
    In building development, concrete is world most reliable, durable and versatile in construction materials. However, the heating and cooling system of the building is influenced by outside temperature due to extreme weather or areas condition leads to the consumption of a lot of electrical power. Thermally insulated concretes represent alternative construction materials to improve the thermal efficiency in building development. Various construction materials have different thermal insulation properties and thus, their suitability for various conditions vary. Thermal insulation properties are generally identified through specific heat, thermal conductivity, thermal diffusivity, thermal expansion, and mass loss. This paper present review the thermal insulation properties of variations insulated concrete are presently in growing demand of researchers to comfort and resolve prescribed issues related to insulated concrete in enhancing thermal insulation properties as a passive energy saving building.
  • Publication
    Single wall carbon nanotubes dispersion study of different dye molecules and chitosan
    Carbon Nanotubes (CNTs) is known for their hydrophobicity ability. However, this ability can become the bottleneck for the application of CNTs where a highly dispersion of materials are needed. In this project, different dispersing agents were investigated namely dye molecules and chitosan. Three different dyes are studied with different concentration, including 0.05 % of chitosan. The dispersion quality is determined by examining through UV-Vis-NIR. The best dispersion quality investigated here is when the concentration of dye molecules is higher, which is around 2.5 mM.
  • Publication
    Image analysis of surface porosity mortar containing processed spent bleaching earth
    ( 2021)
    Beng Wei Chong
    ;
    Rokiah Othman
    ;
    Ramadhansyah Putra Jaya
    ;
    Doh Shu Ing
    ;
    Xiaofeng Li
    ;
    Mohd Haziman Wan Ibrahim
    ;
    ;
    Andrei Victor Sandu
    ;
    Bartosz Płoszaj
    ;
    Janusz Szmidla
    ;
    Tomasz Stachowiak
    Image analysis techniques are gaining popularity in the studies of civil engineering materials. However, the current established image analysis methods often require advanced machinery and strict image acquisition procedures which may be challenging in actual construction practices. In this study, we develop a simplified image analysis technique that uses images with only a digital camera and does not have a strict image acquisition regime. Mortar with 10%, 20%, 30%, and 40% pozzolanic material as cement replacement are prepared for the study. The properties of mortar are evaluated with flow table test, compressive strength test, water absorption test, and surface porosity based on the proposed image analysis technique. The experimental results show that mortar specimens with 20% processed spent bleaching earth (PSBE) achieve the highest 28-day compressive strength and lowest water absorption. The quantified image analysis results show accurate representation of mortar quality with 20% PSBE mortar having the lowest porosity. The regression analysis found strong correlations between all experimental data and the compressive strength. Hence, the developed technique is verified to be feasible as supplementary mortar properties for the study of mortar with pozzolanic material.
  • Publication
    Parametric studies on radiation grafting of tripropylene glycol diacrylate onto waste tire dust
    ( 2024-12)
    S. S. M. Shirajuddin
    ;
    C. T. Ratnam
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    Waste tire dust (WTD) was activated and modified via an electron beam to graft with tripropylene glycol diacrylate (TPGDA) monomer. This process was investigated in conjunction with reaction parameters, namely, monomer concentration, absorbed dose, grafting temperature, and grafting time. The effect of grafting conditions on the grafting yield (GY) was explored. It was found that GY increased with the increase of absorbed dose, TPGDA monomer concentration, and the grafting temperature. However, a further increase in the grafting reaction time did not affect the GY. The radiation-induced grafting technique used in this study was successful, with the maximum GY of 24.72 at an optimum grafting parameter of 5 w/v% TPGDA concentration, 60 kGy irradiation dose, 3 hours reaction time, and 60 °C reaction temperature. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were employed to provide evidence for the formation of graft copolymers in the grafting systems. It is evident from the FTIR analysis that the radiation grafting method successfully introduced a large number of carbonyl groups onto the WTD surface, as demonstrated by the emergence of a new peak at 1720 cm-1. The surface morphology of the grafted WTD appeared thicker, swelled, and coated compared to non-grafted WTD, followed by the integration of the TPGDA monomer into the backbone of the WTD, resulting in the expansion of the WTD's average diameter by approximately 111.5%. The results of the present study demonstrate that radiation-induced grafting techniques can be successfully employed to prepare grafted WTD.
  • Publication
    Microstructural Analysis of Fly Ash-based Geopolymers with various Alkali Concentration
    ( 2019-08-14)
    Hui-Teng N.
    ;
    ;
    Yun-Ming L.
    ;
    ;
    Yong-Sing N.
    In the present work, a comparative study on the effect of different concentration of sodium hydroxide (NaOH) on fly ash-based geopolymer was investigated. The geopolymer synthesis by mixing fly ash with alkali activator (a mixture of NaOH and sodium silicate) at solid/liquid ratio of 2.5. The NaOH were used 6M, 8M, 10M, 12M and 14M with constant sodium silicate/NaOH ratio of 2.5. The geopolymers were cured at room temperature (29°C) for 24 hours and 60°C in oven for another 24 hours. The testing and analysis of the fly ash-based geopolymers were performed after 28 days. The adequate Na+ ions and densified microstructure were observed at optimum 8M-NaOH-activated fly ash-based geopolymers.