UTILIZATION OF FLY ASH AND CONCRETE RESIDUE IN THE PRODUCTION OF GEOPOLYMER BRICKS

2017 ◽  
Vol 12 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Siriporn Sirikingkaew ◽  
Nuta Supakata

This study presents the development of geopolymer bricks synthetized from industrial waste, including fly ash mixed with concrete residue containing aluminosilicate compound. The above two ingredients are mixed according to five ratios: 100:0, 95:5, 90:10, 85:15, and 80:20. The mixture's physico-mechanical properties, in terms of water absorption and the compressive strength of the geopolymer bricks, are investigated according to the TIS 168-2546 standard. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses are used to investigate the microstructure and the elemental and phase composition of the brick specimens. The results indicate that the combination of fly ash and concrete residue represents a suitable approach to brick production, as required by the TIS 168–2546 standard.

Elkawnie ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cut Rahmawati ◽  
Sri Aprilia ◽  
Taufiq Saidi ◽  
Teuku Budi Aulia

Abstract: This study was designed to examine the mineral, microstructural, and mechanical strength properties of fly ash and its feasibility as a raw material for geopolymer cement. The study used an experimental method by examining the characteristics of fly ash by X-ray Fluorescence Spectrometer (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), hydrometer method, Scanning electron microscopy (SEM), and compressive strength testing. For creating the geopolymer cement paste, a concentration of NaOH 10M was used, with a ratio of water/solid = 0.4 and a ratio of Na2SiO3/NaOH = 1 using curring at room temperature. The results showed the geopolymer pastes have a compressive strength of 18.1 MPa and 21.5 MPa after 7 days and 28 days. The XRD results showed a decrease in the peak of 2θ at 26.54° because the amorphous part had transformed into a C-S-H solution in geopolymer cement. This finding was supported by the FTIR spectra results showing Si-O-Si bending vibration and the functional group of AlO2. It showed that Nagan Raya fly ash-based geopolymer is a potential construction material.Abstrak: Penelitian ini dirancang untuk mendapatkan sifat mineral, mikrostruktural, dan kekuatan mekanis dari fly ash serta kesesuaiannya sebagai material dasar pada semen geopolimer. Metode penelitian yang digunakan adalah metode eksperimen dengan cara  menguji karakteristik dari fly ash dengan pengujian X-ray Fluorescense Spectrometer (XRF), Fourier transform infrared (FTIR) spectoscopy, X-ray diffraction (XRD), hydrometer method, Scanning electron microscopy (SEM) dan kuat tekan.  Untuk pembuatan pasta semen geopolimer digunakan konsentrasi NaOH 10 M, rasio water/solid 0,4 dan rasio Na2SiO3/NaOH = 1 dengan perawatan pada suhu kamar. Hasil menunjukkan setelah 7 hari pasta geopolimer memiliki kuat tekan 18,1 MPa dan 21,5 MPa pada 28 hari. Hasil XRD menunjukkan adanya penurunan puncak 2θ pada 26,54° ini disebabkan karena bagian amorf dari fly ash telah menjadi larutan C-S-H pada semen geopolimer. Hasil ini diperkuat dengan analisis FTIR spectra yang menunjukkan adanya Si-O-Si bending vibration dan gugus fungsi dari AlO2. Hasil menunjukkan fly ash dari Nagan Raya potensial sebagai bahan material konstruksi berbasis geopolimer.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9059-9074
Author(s):  
Zehua Zhu ◽  
Cheng Cheng ◽  
Debin Zhu ◽  
Dewen Liu ◽  
Yafei Zhang

Portland cement-based composites were prepared with coffee exocarp (pretreated with water or NaOH) via vacuum extraction technology. An orthogonal test was adopted to analyze the influence of various factors on mechanical properties of the composite. The morphology and composition of the pretreated coffee exocarp and composites were analyzed via environmental scanning electron microscopy and X-ray diffraction, respectively. The results showed that the coffee exocarp content and vacuum extraction time significantly affected the compressive strength. An addition of 10% coffee exocarp had a slight negative effect on the mechanical properties but enhanced the crack inhibition and overall toughness of the composite. The scanning electron microscopy and X-ray diffraction results showed that the composite containing coffee exocarp pretreated with 4% NaOH solution had the highest density and exhibited the best properties due to mechanical interlocking between the coffee exocarp and cement. After 28 d of curing, the composites exhibited a maximum compressive strength of 15.72 MPa, a mass that was approximately 37% less than that of ordinary Portland cement samples, and a bulk density of 1.5 g/cm3 to 1.6 g/cm3. Hence, the produced biocomposites could be used for low-load pavements, providing a new type of economical building material.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.


2021 ◽  
Vol 12 (5) ◽  
pp. 6580-6588

Dicalcium phosphate dihydrate (DCPD) nanoparticles, also known as brushite, are considered an important bioceramic compound. In this study, brushite was prepared from Moroccan phosphogypsum (PG) using a new sol-gel method. A two-step technique undergoes the synthesis of brushite, the preparation of anhydrite from PG followed by adding phosphoric acid in the presence of sodium hydroxide. The morphology, the chemical composition, and the crystallites size were obtained using Scanning Electron Microscopy (SEM-EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), respectively. According to the Debye-Scherrer equation, these characterization methods indicated that the synthesized brushite was highly pure according to the Ca/P ratio of 1.14 and an average crystallites size estimated at 66 nm. These results proved that the brushite was successfully synthesized from Moroccan phosphogypsum.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4171 ◽  
Author(s):  
Paweł Rutkowski ◽  
Jan Huebner ◽  
Adrian Graboś ◽  
Dariusz Kata ◽  
Dariusz Grzybek ◽  
...  

In this study, the influence of the addition of rare earth oxides on the phase composition and density of KNN piezoelectric ceramics was investigated. The initial powders of Na2CO3 and K2CO3 were dried at 150 °C for 2 h. Then, a powder mixture for synthesis was prepared by adding a stoichiometric amount of Nb2O5 and 5 and 10 wt % overabundance of Na2CO3. All powders were mixed by ball-milling for 24 h and synthesized at 950 °C. The phase composition of the reaction bed was checked by means of X-ray diffraction (XRD). It had an appearance of tetragonal and monoclinic K0.5Na0.5NbO3 (KNN) phases. Then, 1 and 2 wt % of Er2O3 and Yb2O3, were added to the mixture. Green samples of 25 mm diameter and 3 mm thickness were prepared and sintered by hot pressing at 1000 °C for 2 h under 25 MPa pressure. The final samples were investigated via scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS), XRD, Rietveld, and ultrasonic methods. Phase analysis showed tetragonal and orthorhombic KNN phases, and a contamination of (K2CO3·1.5H2O) was present. The obtained KNN polycrystals had a relative density above 95%. Texturing of the material was confirmed as a result of hot pressing.


2008 ◽  
Vol 368-372 ◽  
pp. 977-979
Author(s):  
Sheng Li Jin ◽  
Ya Wei Li ◽  
Jing Liu ◽  
Yuan Bing Li ◽  
Lei Zhao ◽  
...  

AlN/Al ceramic composite was fabricated by directed melt nitridation of pure Al block covered with 10wt% Mg powder at 1300°C in a high purity flowing N2. Microstructure and phase composition of the composite were investigated by scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction. Results showed that AlN is the main phase in the composite and its lattice parameters of a and c are 3.1110Å and 4.9806Å, respectively. The phase composition of the composite changes along the growth direction and a gradient sandwich structure forms. The surface of the composite is made up of a dense and thin nodular AlN layer, underneath which an AlN/Al layer appears, followed by an AlN/Al/MgAl2O4 layer. Thermodynamic calculations predicted the formation of possible phases with the addition of Mg. It suggested that the content of Mg at the reaction frontier of nitridation is considerably lower to 0.15wt% where MgAl2O4 was stable, because of escape and reaction exhaustion of Mg. Once Mg is lower than 0.05wt%, only a dense AlN layer can exist, which prevents the further nitridation of Al melt.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Ruy A. Sá Ribeiro ◽  
Marilene G. Sá Ribeiro ◽  
Gregory P. Kutyla ◽  
Waltraud M. Kriven

To determine the viability of using a local resource for geopolymer synthesis, geopolymers were synthesized using metakaolin made from clay mined in the Amazonian region of Brazil. Samples were made with mixed potassium-sodium and pure sodium metakaolin-based geopolymer. Samples were also made using commercial metakaolin (CMK) from BASF, Inc. as a comparison to the Amazonian metakaolin (AMK). Scanning electron microscopy was used to investigate the microstructure of the materials. X-ray diffraction was able to confirm the formation of geopolymer. The mechanical properties of AMK material were nearly equivalent to those based on CMK. Neither CMK nor AMK reacted completely, although samples made with CMK showed less unreacted material. By increasing the mixing intensity and duration, the amount of residual unreacted material was substantially reduced, and mechanical properties were improved.


2010 ◽  
Vol 152-153 ◽  
pp. 1683-1686
Author(s):  
Qing Wang ◽  
Ya Hui Zhang

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.


2012 ◽  
Vol 602-604 ◽  
pp. 526-529
Author(s):  
Qing Wang ◽  
Lin Zhang ◽  
Ya Hui Zhang

Biomorphic TiO2 was prepared by high temperature pyrolysis and a modified sol-gel route. The morphology and microstructure of TiO2 samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the biomorphic TiO2 mainly consists of rutile TiO2, and replicates the shape and part microstructure of the carbon template.


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