Wyniki wyszukiwania - BazTech

1

Geopolimery: nadchodząca rewolucja czy ślepy zaułek?

Gołek Łukasz

Budownictwo, Technologie, Architektura

|

2024

|

nr 2

60--64

PL

Niniejsze opracowanie analizuje potencjał spoiw geopolimerowych jako alternatywy dla tradycyjnych cementów. Poprzez przegląd historii, właściwości i możliwości zastosowania geopolimerów, autor przedstawia ocenę zasadności ich produkcji w kontekście współczesnych wyzwań klimatycznych i technologicznych. Pomimo pewnych korzyści, jakie niosą za sobą geopolimery, istnieją poważne obawy dotyczące ich skuteczności i trwałości w porównaniu z konwencjonalnymi cementami, a przede wszystkim informacje dotyczące śladu węglowego, co często nieprawdziwie deklarowane jest jako ich główna zaleta.

EN

This study examines the potential of geopolymer binders as an alternative to traditional cements. By reviewing the history, properties and possible applications of geopolymers, the author presents an assessment of the viability of their production in the context of contemporary climatic and technological challenges. Despite some benefits that geopolymers bring, there are serious concerns about their effectiveness and durability compared to conventional cements, and above all, information about their carbon footprint, which is often falsely declared as their main advantage.

2

Wytrzymałość na zginanie oraz ściskanie materiałów geopolimerowych otrzymanych z wykorzystaniem odpadów poprodukcyjnych

Kaźmierowski Hubert, Prałat Karol, Koper Artur

Przegląd Budowlany

|

2023

|

R. 94, nr 7-8

147--150

PL

Artykuł przedstawia wstępne wyniki badań wytrzymałości na zginanie oraz ściskanie innowacyjnych materiałów geopolimerowych. Geopolimery zostały wykonane według dwóch receptur. Pierwszy produkt był próbą kontrolną (odniesienia), a drugi - próbą modyfikowaną (docelową). Przedstawione zostały również wyniki badań gęstości otrzymanych materiałów budowlanych. Wykazano możliwości zastąpienia czystych chemicznie substratów w procesie geopolimeryzacji materiałami odpadowymi.

EN

The article presents the preliminary results of bending and compressive strength tests of innovative geopolymer materials. Geopolymers were made according to two recipes. The first product was the control (reference) sample and the second was the modified (target) sample. The results of density tests of the obtained building materials were also presented. The possibilities of replacing chemically pure substrates in the geopolymerization process with waste materials have been demonstrated.

3

Właściwości fizyczno-mechaniczne autoklawizowanych kompozytów geopolimerowych

Konstańczuk Dominika, Halicki Dawid, Kalinowska-Wichrowska Katarzyna, Bołtryk Michał

Materiały Budowlane

|

2023

|

nr 1

10--14

PL

W artykule przedstawiono wyniki podstawowych badań: wytrzymałości na zginanie i ściskanie; nasiąkliwości wagowej i gęstości objętościowej autoklawizowanych kompozytów geopolimerowych z dodatkiem recyklatu geopolimerowego. Jako zmienne przyjęto: zawartość recyklatu z geopolimerów, stanowiącą część mieszanki popiołowo-żużlowej oraz współczynnik aktywator/spoiwo. Wyniki wskazują, że zastosowanie materiału z recyklingu geopolimerów poprawia badane cechy kompozytów.

EN

The article presents the results of basic tests: bending and compressive strength, water absorption by weight and volumetric density of autoclaved geopolymer composites with the addition of geopolymeric recyclate. A variable content of geopolymer recyclate was assumed as part of the ash-slag mixture and a variable activator/binder ratio. The results indicate that the use of geopolymer recycled material improves the examined properties of composites.

4

Impact of Sulfate in the Sand on the Absorption and Density of Metakaolin-Based Geopolymer Mortar

Thamer Sara Yahya, Al-Jaberi Layth Abdulbari

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 1

328--335

EN

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).

5

Development of lightweight geopolymer composites containing perlite and vermiculite

Korniejenko K., Pławecka K., Bulut A., Şahin B., Azizağaoğlu G., Figiela B.

Journal of Achievements in Materials and Manufacturing Engineering

|

2023

|

Vol. 117, nr 2

49--56

EN

Purpose: The aim of this work was to prepare and characterise geopolymer composites containing lightweight aggregates - perlite and vermiculite. Design/methodology/approach: The geopolymer matrix was prepared on the basis of fly ash, sand and a 6M sodium hydroxide solution with sodium silicate. The properties of the materials were tested 28 days after the preparation of the samples. The following research methods were used to characterise the composites: compressive and flexural strength tests, microstructural tests using a scanning electron microscope, and thermal conductivity were measured. Findings: The results obtained showed a slight effect of the additives on the strength properties. Lightweight aggregates are characterised by good coherence with the matrix material. Their addition allowed to reduce the density and lowered the thermal conductivity of the materials. The results obtained indicate that the proposed additives can improve the properties of the geopolymer composite for use in the construction industry. Research limitations/implications: Further research should focus on geopolymer composites with perlite and involve fire-resistant and water-absorption tests. Practical implications: The production of lightweight building materials brings a number of benefits, such as reducing the density of building elements and, at the same time, the entire structure, which results in a reduction in their weight, as well as lower transport costs. Such elements have better thermal and acoustic insulation, reflected in the parameters of buildings. An additional advantage is the reduced environmental impact through better insulation properties, lower fuel consumption during transport, etc. Originality/value: The density of the material can be reduced by using lightweight aggregates or obtaining porous material in the foamed process. In the case of geopolymer composites, a number of studies related to foamed materials have been provided, but there is only a few previous research connected with lightweight aggregates such as perlite and vermiculite.

6

Wpływ dodatku napowietrzającego na przewodność cieplną zapraw geopolimerowych

Kępniak Maja, Prochoń Piotr, Piątkiewicz Wojciech

Cement Wapno Beton

|

2023

|

R. 28, nr 3

186--193

PL

Artykuł dotyczy badań nad zrównoważonymi materiałami budowlanymi - zaprawami aktywowanymi alkaliami o dużej odporności termicznej. Badania przeprowadzono z wykorzystaniem bezcementowego spoiwa z popiołów lotnych ze spalania węgla, metakaolinitu i zeolitu, aktywowanego alkalicznie [geopolimeru] z zastosowaniem piasku i pyłu perlitowego oraz mikrosfer jako dodatków potencjalnie zwiększających izolacyjność termiczną kompozytów. Celem badań była weryfikacja wpływu tych modyfikatorów na współczynnik przewodności cieplnej, wytrzymałość na ściskanie i mikrostrukturę zapraw bezcementowych. Wyniki pokazały, że najbardziej skutecznym dodatkiem okazał się piasek perlitowy w ilości 30%. Pozostałe badane wypełniacze lekkie nie zmieniły w znaczny sposób przewodności cieplnej badanych zapraw.

EN

The article deals with research on sustainable building materials - alkali-activated mortars with high temperature resistance. A cement-free alkali-activated binder [geopolymer] based on alkali-activated fly ash from coal combustion using perlite, perlite dust and cenospheres as filler. The object of the analysis was to study the effect of fillers on the coefficient of thermal conductivity, compressive strength and microstructure of the cementless mortars. The results showed that the most effective addition was perlite sand in the amount of 30%. The other tested lightweight fillers did not significantly change the thermal conductivity of the tested mortars.

7

Properties and Morphology of Fly Ash Based Alkali Activated Material (AAM) Paste Under Steam Curing Condition

Razak Rafiza Abd, Izman Sharifah Nur Syamimi Syed, Abdullah Mohd Mustafa Al Bakri, Yahya Zarina, Abdullah Alida, Mohamed Rosnita

Archives of Metallurgy and Materials

|

2023

|

Vol. 68, iss. 2

785--789

EN

This 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.

8

Infrared Imaging as a Non-Destructive Testing Method for Geopolymer Concrete

Kusbiantoro Andri, Ismail Amalina Hanani, Jema’in Sri Khatijah, Muthusamy Khairunisa, Zainal Farah Farhana

Archives of Metallurgy and Materials

|

2023

|

Vol. 68, iss. 3

1047--1052

EN

Non-destructive testing (NDT) is generally used to estimate the compressive strength of concrete material without compromising its structural integrity. However, the available testing methods on the market have particular limitations that may restrict the accuracy of the results. Therefore, this study aimed to develop a new technique for measuring the compressive strength of geopolymer concrete using infrared imaging analysis and Thermal Diameter Variation (TDV) rate. The compressive strength range was designed within the target strength of 20, 30 and 40 MPa. The infrared image was captured on the preheated concrete surface using FLIR-ONE infrared camera. Based on the correlation between TDV rate and compressive strength, higher accuracy was obtained in the orange contour with an R2 of 0.925 than in the red contour with an R2 of 0.8867. It is apparent that infrared imaging analysis has excellent reliability to be used as an alternative NDT by focusing on the warmer region during the procedure.

9

Influence of Sintering Temperature on the Pore Structure of an Alkali-Activated Kaolin Based Geopolymer

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

Archives of Metallurgy and Materials

|

2023

|

Vol. 68, iss. 3

987-989

EN

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.

10

Study of Zn(II) ion removal from galvanic sludge by geopolymers

Sitarz-Palczak Elżbieta

Archives of Environmental Protection

|

2023

|

Vol. 49, no 4

11--20

EN

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.

PL

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

11

A Potential Environmental Sustainability of Wood Ash in Normal and Geopolymer Concrete – A Review

Nura Isa Muhammad, Awang Hanizam, Muthusamy Khairunisa

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 4

1--20

EN

The production of cement for concrete has led to the emission of carbon dioxide (CO₂) into the atmosphere, which has contributed to global warming. Moreover, the excessive amount of industrial waste from biomass energy production landfilled in our environments is continuously causing sustainability challenges. However, several studies were carried out to ascertain the possibilities of using these waste materials in concrete production to address the cement and waste disposal sustainable issues simultaneously. The present study reviewed multiple studies that were carried out on wood ash (WA) application in both normal and geopolymer concrete with an emphasis on fresh, hardened, and durability properties. WA effects as a pozzolanic material are summarized for its application in mortar/concrete production. WA can be used to replace cement in mortar/concrete at up to 20% replacement level, similarly, in geopolymer production, it was revealed that WA can be effectively utilized to replace ground granulated blast furnace slag (GGBS) or pulverized fly ash (PFA) at up to 50% replacement level. The sustainability impacts of WA utilization in concrete production were presented and discussed. Results of these findings revealed its suitability as supplementary cementitious material, but still there exists a gap in its utilization in geopolymer concrete.

12

A brief overview of the use of additive manufacturing of con-create materials in construction

Mierzwiński Dariusz, Łach Michał, Gądek Szymon, Lin Wei-Ting, Hung Tran Doan, Korniejenko Kinga

Acta Innovations

|

2023

|

no. 48

22--37

EN

Currently, additive technology is becoming increasingly popular in different areas, including its applications in construction industry. The main aim of the chapter is to show the selected applications of 3D printing technology in the construction industry and the usage of this technology on distinct stages of a construction project, from architectural design to performance of residential buildings and other civil engineering constructions. The chapter is based on a critical analysis of the literature sources, as well as the authors' experiences. The data collected are supported by selected case studies from five projects. The main findings show that 3D printing brings a lot of advantages in the construction industry, for instance: low labour costs, less waste, and high efficiency, but it still requires development and optimization.

13

Problems of measuring the electrical parameters of geopolymer concretes

Kozioł Michał, Zygarlicki Jarosław, Zmarzły Dariusz, Janowska-Renkas Elżbieta

Przegląd Elektrotechniczny

|

2022

|

R. 98, nr 10

233--236

EN

The article presents the problems of measuring electrical parameters on the example of determining the resistivity of concrete samples. In addition, as part of the research work undertaken, a series of experimental measurements were carried out in the system of two electrodes on various samples of geopolymer concrete. The obtained results showed the need to improve the electrodes and subjecting to a detailed analysis of the contact connections between the electrodes and the sample in order to obtain a repeatable method of determining the resistivity of geopolymeric concrete samples.

PL

W artykule przedstawiono problematykę pomiarów parametrów elektrycznych na przykładzie wyznaczania rezystywności próbek betonowych. Ponadto w ramach podjętych prac badawczych, przeprowadzono serię pomiarów eksperymentalnych w układzie dwóch elektrod na różnych próbkach betonu geopolimerowego. Uzyskane rezultaty wykazały konieczność udoskonalenia elektrod i poddanie szczegółowej analizie połączeń stykowych pomiędzy elektrodami a próbką, celem uzyskania powtarzalnej metody wyznaczania rezystywności próbek betonów geopolimerowych.

14

Wybrane właściwości geopolimerów z wykorzystaniem żużla powstałego w wyniku zgazowania plazmowego odpadów medycznych

Ciemnicka Justyna, Prałat Karol, Koper Artur, Brych-Dobrowolska Małgorzata, Buczkowska Katarzyna

Przegląd Budowlany

|

2022

|

R. 93, nr 9-10

146--148

PL

W artykule przedstawiono wyniki badań dotyczących wpływu żużla powstałego w wyniku zgazowania plazmowego odpadów medycznych na: przewodność cieplną, objętościową pojemność cieplną oraz dyfuzyjność cieplną, modyfikowanych geopolimerów. Badania dotyczyły kompozytu geopolimerowego na bazie metakaolinu aktywowanego szkłem wodnym potasowym. Stwierdzono, że dodatek 10% masowych zmielonego żużla w stosunku do proszku glinokrzemianowego zmniejszył wartość współczynnika przewodzenia ciepła o 40%. Kompozyty modyfikowane żużlem charakteryzują się również niższymi wartościami dyfuzyjności cieplnej i objętościowej pojemności cieplnej.

EN

The article presents the results of research on the influence of slag formed as a result of plasma gasification of medical waste on: thermal conductivity, volumetric heat capacity and thermal diffusivity of modified geopolymers. The research concerned a geopolymer composite based on metakaolin activated with potassium water glass. It was found that the addition of 10% by mass of the ground slag in relation to the aluminosilicate powder decreased the value of the thermal conductivity coefficient by 40%. Slag-modified composites are also characterized by lower values of thermal diffusivity and volumetric heat capacity.

15

Resistance of geopolymers to chemical aggression. Literature study

Słomka-Słupik Barbara, Wiśniewska Paulina

Ochrona przed Korozją

|

2022

|

nr 12

378--392

EN

Geopolymers, or mineral polymers, are binders formed as a result of the alkaline activation of anthropogenic or natural minerals. Recently, they have attracted the attention of many scientists who justify the need to reduce carbon dioxide emissions during cement production by using other materials. The paper lists the materials used in the production of geopolymer binders, describes the geopolymerization process, and characterizes the method of corrosion of cement binders in relation to the results of research carried out on geopolymer binders. The main focus was on the resistance of geopolymers to chemical factors such as acids, sulphates, carbon dioxide and ammonium salts. Chloride penetration was indicated in the context of water absorption depending on the geopolymeric matrix microstructure. The results of the research on the reaction of alkali-silicate geopolymers are also described. Research presented mainly by foreign research units confirmed that geopolymer binders are characterized by much better properties than cement binders.

PL

Geopolimery, czyli mineralne polimery, to spoiwa powstające wskutek alkalicznej aktywacji minerałów antropogenicznych lub naturalnych. W ostatnim czasie skupiły uwagę wielu naukowców uzasadniających potrzebę redukcji emisji dwutlenku węgla wydzielającego się podczas wytwarzania cementu przez użycie innych materiałów. W pracy wyszczególniono materiały stosowane w produkcji spoiw geopolimerowych, opisano proces geopolimeryzacji i scharakteryzowano budowę geopolimerów. Porównano również sposób destrukcji materiałów cementowych z geopolimerowymi. Skupiono się głównie na odporności geopolimerów na działanie czynników chemicznych: kwasów, siarczanów, dwutlenku węgla, soli amonowych. Wskazano na wnikanie chlorków jako przykład transportu zależnego od mikrostruktury geopolimerowej matrycy, od możliwości wnikania wody. Opisano również wyniki badań reakcji alkalia-krzemionka zachodzącej w betonach. W badaniach, prezentowanych głównie przez jednostki zagraniczne, potwierdzono, że spoiwa geopolimerowe charakteryzują się dużo lepszymi właściwościami aniżeli spoiwa cementowe.

16

Podstawowe właściwości geopolimerów z dodatkiem odpadu ceramicznego

Chuczun Aleksandra, Rakowski Bartosz, Gosk Edyta, Kalinowska-Wichrowska Katarzyna

Materiały Budowlane

|

2022

|

nr 8

80--83

PL

W artykule przedstawiono podstawowe właściwości geopolimerów z dodatkiem miału ceramicznego, tj.: wytrzymałość na zginanie i ściskanie, nasiąkliwość wagową, gęstość objętościową. Wykonano analizę SEM kompozytów i badania chemiczne surowców. Przyjęto stałą zawartość dodatku odpadowego, zmienną temperaturę wygrzewania i zawartość aktywatora. Wyniki wskazują na korzystny wpływ dodatku miału ceramicznego na badane cechy kompozytów.

EN

The article presents the basic properties of geopolymers with the use of ceramic fines, i.e. flexural and compressive strength, water absorption, bulk density. SEM analysis of composites and chemical tests of research raw materials were performed. A constant content of waste additive, a variable curing temperature and activator content were assumed. The results show a beneficial effect of the addition of ceramic fines on the examined properties of the composites.

17

Kształtowanie właściwości materiałów geopolimerowych w zależności od modułów molowych SiO2/Al2O3 oraz SiO2/Na2O

Sikora Szymon, Skowera Karol, Hynowski Mariusz, Rusin Zbigniew

Cement Wapno Beton

|

2022

|

R. 27, nr 2

115--125

PL

Sektor budowlany jest odpowiedzialny za około 37% światowej emisji dwutlenku węgla [CO2], do atmosfery. Z tego względu ograniczenie jego emisji oraz ograniczenie emisji innych gazów cieplarnianych, w tym sektorze, ma szczególne znaczenie wobec postępujących zmian klimatycznych. Ważne jest, aby nowe wyroby budowlane cechował mniejszy wpływ na środowisko naturalne, podczas ich całego cyklu życia, a ich produkcja została oddzielona od wykorzystania energii pierwotnej. W niniejszej pracy zbadano wybrane właściwości materiałów geopolimerowych. Geopolimery to nieorganiczne, amorficzne polimery glinokrzemianowe, które w określonych zastosowaniach mogą stanowić alternatywę dla wyrobów, zastępując cement portlandzki. W niniejszej pracy przedstawiono właściwości zapraw geopolimerowych, m.in. porowatość oraz wytrzymałość mechaniczną, w zależności od ich składu chemicznego. Ten ostatni opisany przez odpowiednie stosunki molowe tlenków SiO2/Al2O3 oraz SiO2/Na2O. Wyniki badań pokazują, iż wzrost zawartości SiO2 względem Al2O3 w mieszaninie reakcyjnej wpływa na zmniejszenie porowatości zapraw geopolimerowych. Zaprawy o dużym module molowym SiO2/Al2O3 mają zwartą i szczelną mikrostrukturę oraz wysoką wytrzymałość mechaniczną. Podobny efekt otrzymano stosując wyższe stężenia roztworu wodorotlenku sodu [NaOH], w stosunku do roztworu krzemianu sodu [Na2SiO3], w mieszaninie aktywatora w procesie geopolimeryzacji.

EN

The construction sector is responsible for around 37% of global emissions of the carbon dioxide to the atmosphere. Therefore, reducing gas emissions, in this construction sector, is particularly important, given the progressing climate change. For this reason, limiting its emissions and limiting the emission of other greenhouse gases in this sector, is of particular importance in view of the progress of climate change. It is important that new construction products have less impact on the environment during their entire life cycle, and their production has been decoupled from the use of primary energy. In this work, selected properties of geopolymeric materials were examined. Geopolymers are inorganic aluminosilicate polymers with an amorphous microstructure, which may be an alternative in certain applications, for products based on Portland cement. Here, the properties of geopolymer mortars, i.e. porosity, microstructure and mechanical strength, were compared. The influence of the composition of reaction mixture on these properties, defined by the appropriate SiO2/Al2O3 and SiO2/Na2O molar ratios, was also defined. The results show that increasing the content of SiO2 in relation to Al2O3 in the composition of the reaction mixture, reduces porosity. Thus, leading to a more compact microstructure and higher mechanical strength. A similar effect occurs when a higher NaOH solution concentration is used, in comparison to the sodium silicate [Na2SiO3] solution.

18

The Investigation of Ground Granulated Blast Furnace Slag Geopolymer at High Temperature by Using Electron Backscatter Diffraction Analysis

Aziz Ikmal Hakem, Al Bakri Abdullah Mohd Mustafa, Salleh Mohd Arif Anuar Mohd, Yoriya Sorachon, Razak Rafiza Abd, Mohamed Rosnita, Baltatu Madalina Simona

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 1

227--231

EN

This paper elucidated the potential of electron backscatter diffraction analysis for ground granulated blast furnace slag geopolymers at 1000°C heating temperature. The specimen was prepared through the mechanical ground with sandpaper and diamond pad before polished with diamond suspension. By using advanced technique electron backscatter diffraction, the microstructure analysis and elemental distribution were mapped. The details on the crystalline minerals, including gehlenite, mayenite, tobermorite and calcite were easily traced. Moreover, the experimental Kikuchi diffraction patterns were utilized to generate a self-consistent reference for the electron backscatter diffraction pattern matching. From the electron backscatter diffraction, the locally varying crystal orientation in slag geopolymers sample of monoclinic crystal observed in hedenbergite, orthorhombic crystal in tobermorite and hexagonal crystal in calcite at 1000°C heating temperature.

19

Review on Mechanical Properties of Metakaolin Geopolymer Concrete by Inclusion of Steel Fibers

Faris Meor Ahmad, Al Bakri Abdullah Mohd Mustafa, Muniandy Ratnasamy, Ramasamy Shamala, Abu Hashim Mohammad Firdaus, Junaedi Subaer, Sandu Andrei Victor, Tahir Muhammad Faheem Mohd

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 1

261--267

EN

This study summarised the recent achievement in developing fiber reinforced geopolymer concrete. The factor of replacing Ordinary Portland Cement (OPC) which is due to the emission of carbon dioxide that pollutes the environment globally is well discussed. The introduction towards metakaolin is presented. Besides, the current research trend involved in geopolymer also has been reviewed for the current 20 years to study the interest of researchers over the world by year. Factors that contribute to the frequency of geopolymer research are carried out which are cost, design, and the practicality of the application for geopolymer concrete. Besides, the importance of steel fibers addition to the geopolymer concrete is also well discussed. The fundamental towards metakaolin has been introduced including the source of raw material, which is calcined kaolin, calcined temperature, chemical composition, geopolymerisation process, and other properties. Alkali activators which are mixing solution between sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) have been reviewed. The mechanical properties of fibers reinforced metakaolin-based geopolymer concrete which is compressive and flexural are thoroughly reviewed. The compressive and flexural strength of fiber-reinforced metakaolin geopolymer concrete shows some improvement to the addition of steel fibers. The reviews in this field demonstrate that reinforcement of metakaolin geopolymer concrete by steel fibers shows improvement in mechanical performance.

20

Phase Analysis of Different Liquid Ratio on Metakaolin/Dolomite Geopolymer

Sauffi Ahmad Syauqi, Ibrahim Wan Mastura Wan, Al Bakri Abdullah Mohd Mustafa, Ibrahim Masdiyana, Ahmad Romisuhani, Zaidi Fakhryna Ahmad

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 1

247--250

EN

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.