Temat: geopolymer - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Effect of Sodium Aluminate on the Fresh and Hardened Properties of Fly Ash-Based One-Part Geopolymer
Autorzy:: Ooi, Wan-En
Liew, Yun Ming
Heah, Cheng Yong
Ho, Li-Nge
Abdullah, Mohd Mustafa Al Bakri
Ong, Shee-Ween
Sandu, Andrei Victor
Tematy:: geopolymer
one-part geopolymer
fly ash
sodium aluminate
sodium metasilicate; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2106571.pdf Link otwiera się w nowym oknie
Opis:: The one-part geopolymer binder was synthesis from the mixing of aluminosilicate material with solid alkali activators. The properties of one-part geopolymers vary according to the type and amount of solid alkali activators used. This paper presents the effect of various sodium metasilicate-to-sodium aluminate (NaAlO2/Na2SiO3) ratios on fly ash-based one-part geopolymer. The NaAlO2/Na2SiO3 ratios were set at 1.0 to 3.0. Setting time of fresh one-part geopolymer was examined through Vicat needle apparatus. Mechanical and microstructural properties of developed specimens were analysed after 28 days of curing in ambient condition. The study concluded that an increase in NaAlO2 content delayed the setting time of one-part geopolymer paste. The highest compressive strength was achieved at the NaAlO2/Na2SiO3 ratio of 2.5, which was 33.65 MPa. The microstructural analysis revealed a homogeneous structure at the optimum ratio. While the sodium aluminium silicate hydrate (N-A-S-H) and anorthite phases were detected from the XRD analysis.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Study of Zn(II) ion removal from galvanic sludge by geopolymers
Badania usuwania jonów cynku z osadów galwanicznych przez geopolimery
Autorzy:: Sitarz-Palczak, Elżbieta
Tematy:: waste
fly ash
geopolymer; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/59111274.pdf Link otwiera się w nowym oknie
Opis:: The galvanic sludges contain a number of toxic heavy metals, potentially mobilized as chemically active ions under environmental conditions as. This study explores the application of fly ash-based geopolymers for the removal of Zn ions from galvanizing sludge. In this study, geopolymers, synthesized via the geopolymerization method, were used to remove Zn from post-galvanized sewage sludge. Two types of geopolymers were used, derived from ash from coal combustion and biomass combustion. Structural, morphological, and surface properties were characterized using FTIR and SEM, respectively. In addition, BET and Langmuir isotherms, along with analyses such as t-Plot and BJH method for porous solids were conducted. The results indicate that the geopolymer derived from coal combustion ash is a more effective sorbent for Zn(II) ions, exhibiting a removal efficiency of 99.9%, compared to 40.7% for the geopolymer derived from biomass combustion ash. The FTIR spectra analysis reveals the presence of bonds between the -OH and/or Si-OH groups on the geopolymers’ surface and the Zn(II) ions. The environmentally and economically advantageous process maximizes the recovery of a valuable component at minimal cost, yielding relatively clean monometallic waste suitable for reuse.
Osady galwaniczne zawierają szereg toksycznych metali ciężkich, które w warunkach środowiskowych mogą być mobilne jako chemicznie aktywne jony. W pracy badano możliwość wykorzystania geopolimerów na bazie popiołów lotnych do usuwania jonów Zn z osadu galwanizacyjnego. W pracy do usuwania Zn z galwanicznych osadów ściekowych wykorzystano geopolimery przygotowane metodą geopolimeryzacji. Zastosowano dwa rodzaje geopolimerów, otrzymywane na bazie popiołów ze spalania węgla i popiołów ze spalania biomasy. Strukturę, morfologię i właściwości powierzchni scharakteryzowano odpowiednio za pomocą FTIR i SEM. Dodatkowo wyznaczono izotermę BET i Langmuira oraz przeprowadzono analizę tych izoterm dla ciał porowatych (metoda t-Plot i metoda BJH). Wykazano, że geopolimer otrzymany z popiołów ze spalania węgla jest skuteczniejszym sorbentem dla jonów Zn(II). Skuteczność usuwania jonów Zn(II) dla geopolimeru na bazie popiołów ze spalania węgla wynosi 99,9%, a dla geopolimeru na bazie popiołów ze spalania biomasy 40,7%. Otrzymane rezultaty są wynikiem powstawania wiązań pomiędzy grupami -OH i/lub Si-OH obecnymi na powierzchni zastosowanych geopolimerów a jonami Zn(II), których obecność stwierdzono na podstawie analizy widm FTIR. Procedura ta jest korzystna z ekologicznego i ekonomicznego punktu widzenia ponieważ zapewnia maksymalny odzysk cennego składnika przy możliwie najniższych kosztach. Ponadto, pozwala na uzyskanie stosunkowo czystych odpadów monometalicznych, które można ponownie wykorzystać
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Finite Element Analysis on Structural Behaviour of Geopolymer Reinforced Concrete Beam using Johnson-Cook Damage in ABAQUS
Autorzy:: Mortar, Nurul Aida Mohd
Al Bakri Abdullah, Mohd Mustafa
Hussin, Kamarudin
Razak, Rafiza Abdul
Hamat, Sanusi
Hilmi, Ahmad Humaizi
Shahedan, Noorfifi Natasha
Li, Long Yuan
Aziz, Ikmal Hakem A.
Tematy:: fly ash geopolymer
geopolymer concrete
finite element analysis
Johnson Cook Damage
ABAQUS software; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2174588.pdf Link otwiera się w nowym oknie
Opis:: 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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Effect of Silica Fume and Alumina Addition on the Mechanical and Microstructure of Fly Ash Geopolymer Concrete
Autorzy:: Fong, Sue Min
Heah, Cheng Yong
Liew, Yun Ming
Abdullah, Mohd Mustafa Al Bakri
Hasniyati, Md Razi
Low, Foo Wah
Ng, Hui-Teng
Ng, Yong-Sing
Tematy:: geopolymer
concrete
silica fume
alumina; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2048824.pdf Link otwiera się w nowym oknie
Opis:: This paper discussed the effect of the addition of silica fume (2 wt.% and 4 wt.%) and alumina (2 wt.% and 4 wt.%) on the properties of fly ash geopolymer concrete. The fly ash geopolymer concrete achieved the highest 28-day compressive strength with 2 wt.% of silica fume (39 MPa) and 4 wt.% of alumina (41 MPa). The addition of 2 wt.% of silica fume increased the compressive strength by 105% with respect to the reference geopolymer (without additive). On the other hand, the compressive strength surged by 115% with 4 wt.% of alumina compared to the reference geopolymer. The addition of additives improved the compactness of the geopolymer matrix according to the morphology analysis.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: pH Dependent Degradation and Characterization of Geopolymer Structures Derived from Fly Ash
Autorzy:: Şahbudak, K.
Tematy:: Geopolymer
alkaline
pH
SEM
XRD; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1033454.pdf Link otwiera się w nowym oknie
Opis:: Geopolymer structures are a relatively new family of un-fired ceramics that are produced by alkaline slurry of mixed alumina silicate-based materials. One of the most abundant geopolymer-forming powders is the fly ash. Fly ash is a waste product of thermic coal plants, which produce electricity by coal burning. Fly ashes contain mostly Ca, Al, Si and Fe oxide mixtures and compounds formed during the burning process, followed by sedimentation. The standardization is made by SiO₂ content. Class C ash has low silica content (<50 wt.%) and class F ash has a higher silica content (>50 wt.%). The fly ash, studied in this work, was obtained from Kangal Coal Plant. The NaOH was used as the geopolymer binder and curing was performed at 80% relative humidity, at 40°C in sealed plastic molds. The obtained cylinders were aged for one week before releasing from molds. pH dependent degradation was used to determine the ionic exchange of geopolymers into the solution. Afterwards, XRD and SEM were done to detect the structural changes of geopolymers.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Phase Analysis of Different Liquid Ratio on Metakaolin/Dolomite Geopolymer
Autorzy:: Syauqi Sauffi, Ahmad
Wan Mastura, Wan Ibrahim
Mohd Mustafa Al Bakri, Abdullah
Ibrahim, Masdiyana
Ahmad, Romisuhani
Ahmad Zaidi, Fakhryna
Tematy:: geopolymer
metakaolin
dolomite
phase analysis; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2048822.pdf Link otwiera się w nowym oknie
Opis:: Geopolymer is widely studied nowadays in various scope of studies. Some of the ongoing studies are the study of the various materials towards the geopolymer strength produced. Meanwhile, some of the studies focus on the mixing of the geopolymer itself. This paper discussed the phase analysis of metakaolin/dolomite geopolymer for different solid to the liquid ratio which was, 0.4, 0.6, 0.8, and 1.0, and the properties that affected the geopolymer based on the phases. The constant parameters in this study were the percentage of metakaolin and dolomite used. The metakaolin used was 80% meanwhile dolomite usage was 20%. Besides that, the molarity of NaOH used is 10M and the alkaline activator ratio used is 2.0. All the samples were tested at 28 days of curing. The results show that the 0.8 solid to the liquid ratio used gave better properties compare to other solid to liquid ratio. The phases analyzed were quartz, sillimanite, mullite, and faujasite. The 0.8 S/L ratio shows the better properties compared to others by the test of phase analysis, compressive strength morphology analysis, and functional group analysis.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Impact of Sulfate in the Sand on the Absorption and Density of Metakaolin-Based Geopolymer Mortar
Autorzy:: Thamer, Sara Yahya
Al-Jaberi, Layth Abdulbari
Tematy:: geopolymer
sulfate
molarity
alkaline liquid
absorption; Pokaż więcej
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Powiązania:: https://bibliotekanauki.pl/articles/2202341.pdf Link otwiera się w nowym oknie
Opis:: The advancement of cement alternatives in the construction materials field is fundamental to sustainable development. Geopolymer is the optimal substitute for ordinary portland cement, which produces 80% less CO2 emissions. Metakaolin was used as one of the raw materials in the geopolymerization process. This research examined the influence of three different percentages of sulfate (0.00038, 1.532, and 16.24)% in sand per molarity of NaOH on the absorption and density of metakaolin-based geopolymer mortar (MK-GPM). Samples were prepared with two different molarities (8M and 12M) and cured at room temperature. The best results obtained for geopolymer mortar in the absorption and density test were (3.89%) and (2280 kg/m3), respectively, recorded with 12M with the lowest sulfate content (0.00038%) at 90 days. Moreover, it has been observed that the absorption percentage increased along with sulfate content in the sand, and an inverse relationship was recorded between the increasing sulfate percentages in the sand and density values of (MK-GPM).
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Influence of Sintering Temperature on the Pore Structure of an Alkali-Activated Kaolin Based Geopolymer
Autorzy:: Ramli, Mohd Izrul Izwan
Salleh, Mohd Arif Anuar Mohd
Aziz, Ikmal Hakem
Zaimi, Nur Syahirah Mohamad
Amli, Siti Farahnabilah Muhd
Abdullah, Mohd Mustafa Al Bakri
Tematy:: geopolymer
sintering
pore
density
water absorption; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/59110623.pdf Link otwiera się w nowym oknie
Opis:: Kaolin-based geopolymers are alternatives for producing high-strength ceramics for construction materials. Creating high-performing kaolin ceramics utilizing the regular technique requires a high handling temperature (higher than 1200°C). Thus, the structure and properties such as pore size and distribution are affected at higher sintering temperatures. Along these lines, information with respect to the sintering system and related pore structure is essential for advancing the properties of the previously mentioned materials. This study investigated the microstructure and the density of a kaolin-based geopolymer at various sintering temperatures. The unsintered sample has the highest density of 1610 kg/cm3 , while the samples sintered at 1100°C haves the lowest density of 1203 kg/cm3 . The result also shows that increasing the sintering temperature to 1100°C resulted in increasing the water absorption of the kaolin-based geopolymer ceramic.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Assessment of Geopolymer Concrete for Underwater Concreting Properties
Autorzy:: Zaidi, Fakhryna Hannanee Ahmad
Ahmad, Romisuhani
Al Bakri Abdullah, Mohd Mustafa
Wan Ibrahim, Wan Mastura
Aziz, Ikmal Hakem
Junaidi, Subaer
Luhar, Salmabanu
Tematy:: geopolymer
underwater concrete
fly ash
kaolin; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2106595.pdf Link otwiera się w nowym oknie
Opis:: For ages, concrete has been used to construct underwater structures. Concrete laying underwater is a very complex procedure important to the success or failure of underwater projects. This paper elucidates the influence of alkali activator ratios on geopolymers for underwater concreting; focusing on the geopolymer concrete synthesized from fly ash and kaolin activated using sodium hydroxide and sodium silicate solutions. The geopolymer mixtures were designed to incorporate multiple alkali activator ratios to evaluate their effects on the resulting geopolymers’ properties. The fresh concrete was molded into 50 mm cubes in seawater using the tremie method and tested for its engineering properties at 7 and 28 days (curing). The control geopolymer and underwater geopolymers’ mechanical properties, such as compressive strength, water absorption density, and setting time were also determined. The differences between the control geopolymer and underwater geopolymer were determined using phase analysis and functional group analysis. The results show that the geopolymer samples were optimally strengthened at a 2.5 alkali activator ratio, and the mechanical properties of the control geopolymer exceeded that of the underwater geopolymer. However, the underwater geopolymer was determined to be suitable for use as underwater concreting material as it retains 70% strength of the control geopolymer.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Effect of Solid-To-Liquids and Na2SiO3-To-NaOH Ratio on Metakaolin Membrane Geopolymers
Autorzy:: Ibrahim, Masdiyana
Wan Ibrahim, Wan Mastura
Al Bakri Abdullah, Mohd Mustafa
Sauffi, Ahmad Syauqi
Vizureanu, Petrica
Tematy:: geopolymer
metakaolin membrane
porous geopolymer
solid-to-liquid (S/L) ratio
Na2SiO3/NaOH ratio; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2106597.pdf Link otwiera się w nowym oknie
Opis:: Geopolymer is synthesized by polycondensation of SiO4 and AlO4 aluminosilicate complexes, tetrahedral frames linked with shared sialate oxygen. This paper studies the effect of the solids-to-fluids (S/L) and Na2SiO3/NaOH proportions on the preparing of metakaolin inorganic membrane geopolymer. By consolidating a mixture of metakaolin with sodium hydroxide, sodium silicate and foaming agent, the geopolymer membrane was made in required shape about 1 cm and cured at 80°C for 24 hours. After the curing process, the properties of the samples were tested on days 7. Sodium silicate (Na2SiO32SiO3
Dostawca treści:: Biblioteka Nauki

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