D-45 Development of In Situ X-ray Diffraction System for Hydrothermal Reaction and Its Application to Autoclaved Aerated Concrete Formation

This note describes an autoclave chamber developed and constructed by Anton Paar and its application for in situ experiments under hydrothermal conditions. Reactions of crystalline phases can be studied by successive in situ measurements on a conventional laboratory X-ray diffractometer with Bragg–Brentano geometry at temperatures <483 K and saturated vapour pressure <2 MPa. Variations in the intensity of X-ray diffraction reflections of both reactants and products provide quantitative information for studying the reaction kinetics of both dissolution and crystal growth. Feasibility is demonstrated by studying a cementitious mixture used for autoclaved aerated concrete production. During a period of 5.7 h at 466 K and 1.35 MPa, the crystallization of torbermorite and the partial consumption of quartz were monitored.

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In situ time-resolved X-ray diffraction of tobermorite formation process under hydrothermal condition: Influence of reactive al compound

Powder Diffraction ◽

10.1154/1.3591049 ◽

2011 ◽

Vol 26 (2) ◽

pp. 134-137 ◽

Cited By ~ 2

Author(s):

K. Matsui ◽

A. Ogawa ◽

J. Kikuma ◽

M. Tsunashima ◽

T. Ishikawa ◽

...

Keyword(s):

Hydrothermal Reaction ◽

High Energy ◽

Saturated Steam ◽

Array Detector ◽

Time Interval ◽

X Rays ◽

X Ray Diffraction ◽

Formation Reaction ◽

X Ray

Hydrothermal formation reaction of tobermorite in the autoclaved aerated concrete (AAC) process has been investigated by in situ X-ray diffraction. High-energy X-rays from a synchrotron radiation source in combination with a newly developed autoclave cell and a photon-counting pixel array detector were used. XRD measurements were conducted in a temperature range 100–190°C throughout 12 h of reaction time with a time interval of 4.25 min under a saturated steam pressure. To clarify the tobermorite formation mechanism in the AAC process, the effect of Al addition on the tobermorite formation reaction was studied. As intermediate phases, non-crystalline calcium silicate hydrate (C-S-H), hydroxylellestadite (HE), and katoite (KA) were clearly observed. Consequently, it was confirmed that there were two reaction pathways via C-S-H and KA in the tobermorite formation reaction of Al containing system. In addition, detailed information on the structural changes during the hydrothermal reaction was obtained.

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Influence of Gypsum Additive on the Formation of Tobermorite in Autoclaved Aerated Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.714.116 ◽

2016 ◽

Vol 714 ◽

pp. 116-121 ◽

Cited By ~ 1

Author(s):

Ester Helanova ◽

Rostislav Drochytka ◽

Vit Cerný

Keyword(s):

Chemical Composition ◽

Hydrothermal Reaction ◽

Raw Materials ◽

Fly Ashes ◽

Sem Images ◽

X Ray ◽

Autoclaved Aerated Concrete ◽

Variable Chemical ◽

Aerated Concrete

The quality of the aerated concrete strongly depends on the chemical composition of the raw materials, as well as the process of the hydrothermal reaction during autoclaving. Due to the variable chemical composition of fly ashes, it is necessary to identify the effect of each ion on the formation of the microstructure of aerated concrete. This paper examines the process of formation of tobermorite with the addition of sulphates in various percentage representation. The microstructure of aerated concrete is assessed using SEM images and the mineralogical by means of X-ray analysis.

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Microwave synthesis of a blue luminescent silver(I) coordination polymer with a rigid tris-triazole ligand

Zeitschrift für Naturforschung B ◽

10.1515/znb-2020-0019 ◽

2020 ◽

Vol 75 (6-7) ◽

pp. 545-552

Author(s):

Juan Shi ◽

Zhen-Xiang Xia ◽

Sheng-Chun Chen ◽

Ming-Yang He ◽

Qun Chen

Keyword(s):

Coordination Polymer ◽

Room Temperature ◽

Hydrothermal Reaction ◽

Chain Structure ◽

X Ray Diffraction ◽

Double Chain ◽

X Ray ◽

Triazole Ligand ◽

Hydrolysis Of

AbstractMicrowave-assisted hydrothermal reaction of 2-fluoro-3,5,6-tri(1H-1,2,4-triazol-1-yl)-1,4-benzenedicarbonitrile (L1) with silver(I) nitrate yields a coordination polymer [Ag3(L2)2(NO3)]n (1), in which the L2 ligand (HL2 = 2-hydroxy-3,5,6-tri(1H-1,2,4-triazol-1-yl)terephthalonitrile) is obtained by in situ ligand transformation from the L1 precursor. HL2 monohydrate has also been isolated by the microwave-mediated hydrolysis of L1 and structurally characterized. Single-crystal X-ray diffraction reveals that HL2 monohydrate comprises a zwitterionic HL2 moiety, while complex 1 displays an infinite L2-bridged double-chain structure. Given that the HL2 molecule has a large conjugated π system, complex 1 exhibits strong blue luminescence in the solid state at room temperature.

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Improving Mechanical Properties of Autoclaved Aerated Concrete by Sugar Sediment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.807-809.1266 ◽

2013 ◽

Vol 807-809 ◽

pp. 1266-1269 ◽

Cited By ~ 4

Author(s):

Atthakorn Thongtha ◽

Somchai Maneewan ◽

Chantana Punlek ◽

Yothin Ungkoon

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Flexural Strength ◽

Crystalline Morphology ◽

X Ray Diffraction ◽

Quality Class ◽

X Ray ◽

Autoclaved Aerated Concrete ◽

Aerated Concrete ◽

Scanning Electron

The comparison of microstructure and mechanical properties between the autoclaved aerated concrete (AAC) and the autoclaved aerated concrete consist of sugar sediment (AAC-SS) was investigated in this work. The microstructure of AAC and AAC-SS was analyzed by the scanning electron microscopy (SEM). The mechanical properties of AAC and AAC-SS were focused on the compressive strength, the density, the water absorption and the flexural strength. To comfirm the tobermorite phase, the phase formation of the samples was tested using X-ray diffraction (XRD). It was found that the microstructure of AAC and AAC-SS surface was the finer needle-like crystalline morphology. The compressive strength (5.9 N/mm2) and flexural strength (1.82 N/mm2) of AAC-SS were higher than that of the AAC (5.0 N/mm2 and 1.64 N/mm2). While, the value of density (0.60 g/cm3) and humidity (23.59%) of AAC-SS had little less than that of the AAC (0.61 g/cm3 and 24.11%). The increasing of the tobermorite phase, which was added by the sugar sediment, had affected to the improvement of the mechanical properties. The specimens of both AAC and AAC-SS were claimed in quality class of 4, which based on the Thai Industrial Standard 1505-1998.

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Development of an in situ X-ray Diffraction System for Hydrothermal Reaction

BUNSEKI KAGAKU ◽

10.2116/bunsekikagaku.61.37 ◽

2011 ◽

Vol 61 (1) ◽

pp. 37-47

Author(s):

Jun KIKUMA ◽

Shin-ya MATSUNO

Keyword(s):

Hydrothermal Reaction ◽

X Ray Diffraction ◽

X Ray

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Utilization of Desulfuration Residues in Non-Autoclaved Aerated Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.250-253.707 ◽

2011 ◽

Vol 250-253 ◽

pp. 707-710

Author(s):

Fang Xian Li ◽

You Zhi Chen ◽

Qi Jun Yu ◽

Jiang Xiong Wei

Keyword(s):

Compressive Strength ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Bulk Density ◽

Hydration Products ◽

X Ray Diffraction ◽

X Ray ◽

Autoclaved Aerated Concrete ◽

Aerated Concrete ◽

Scanning Electron

Desulfuration residues were used as aggregate to produce Non-autoclaved aerated concrete. The effects of water-hinder ratio, casting temperature on the gas forming behavior, and those of desulfuration residue content on the compressive strength and bulk density of aerated concrete were investigated. The types of the hydration products and the microstructure of Non-autoclaved aerated concrete with desulfuration residue were investigated by means of X-ray diffraction and scanning electron microscope. Results show that the optimum replacement amount was determined as 50% and at this rate the compressive strength, bulk density of Non-autoclaved aerated concrete were measured as 2.83 MPa and 543 kg/m3. The hydration products of Non-autoclaved aerated concrete with desulfuration residue are C2SH (A) and C2SH (B) along with ettringite and hydrogarnet phases.

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Study of the influence of the secondary raw materials on microstructure and properties of calcium silicate composite

The proceedings of the 13th international conference "Modern Building Materials, Structures and Techniques" (MBMST 2019) ◽

10.3846/mbmst.2019.129 ◽

2019 ◽

Author(s):

Jana Húšťavová ◽

Vít Černý ◽

Rostislav Drochytka

Keyword(s):

Calcium Silicate ◽

Raw Materials ◽

Molar Ratio ◽

X Ray Diffraction ◽

X Ray ◽

Autoclaved Aerated Concrete ◽

Secondary Raw Materials ◽

Aerated Concrete ◽

The Difference ◽

Positive Effect

Calcium silicate composites are a widely used building material, especially autoclaved aerated concrete or sand-lime bricks. The physico-mechanical properties of these materials depend on their microstructure. Microstructure is characterized by the content of crystalline calcium silicate compounds that arise during autoclaving. This is in particular the tobermorite mineral, which carries the mechanical strength of the composite. This paper focuses on the influence of secondary raw materials on properties and microstructure of the calcium silicate composite. Secondary raw materials were selected as slag from the combustion of lignite and ground glass. Mixtures of composites were selected with respect to the required C/S molar ratio of 0.73. The hydrothermal treatment was carried out at a temperature of 190 °C and a residence time of 4, 8 and 16 hours. The microstructure of calcium silicate composites and autoclaved aerated concrete was studied. The use of slag resulted in an increase in the intensity of the diffraction line of tobermorite by X-ray diffraction analysis as well as the use of glass. The difference was particularly evident in the shape of the tobermorite crystals. Long strong crystals were detected in the sample with slag, while the sample with glass exhibited low tobermorite leaves. Porous structure of autoclaved aerated concrete with slag was uniform, unlike samples with glass. Both materials have a positive effect on the increase in compressive strengths of the samples.

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