scholarly journals Effect of Calcination Temperature on Mechanical Properties of Magnesium Oxychloride Cement

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 607
Author(s):  
Chenggong Chang ◽  
Lingyun An ◽  
Rui Lin ◽  
Jing Wen ◽  
Jinmei Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Calcination Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Scanning Electron ◽  
Oxychloride Cement

In order to make full use of magnesium chloride resources, the development and utilisation of magnesium oxychloride cement have become an ecological and economic goal. Thus far, however, investigations into the effects on these cements of high temperatures are lacking. Herein, magnesium oxychloride cement was calcinated at various temperatures and the effects of calcination temperature on microstructure, phase composition, flexural strength, and compressive strength were studied by scanning electron microscopy, X-ray diffraction, and compression testing. The mechanical properties varied strongly with calcination temperature. Before calcination, magnesium oxychloride cement has a needle-like micromorphology and includes Mg(OH)2 gel and a trace amount of gel water as well as 5 Mg(OH)2·MgCl2·8H2O, which together provide its mechanical properties (flexural strength, 18.4 MPa; compressive strength, and 113.3 MPa). After calcination at 100 °C, the gel water is volatilised and the flexural strength is decreased by 57.07% but there is no significant change in the compressive strength. Calcination at 400 °C results in the magnesium oxychloride cement becoming fibrous and mainly consisting of Mg(OH)2 gel, which helps to maintain its high compressive strength (65.7 MPa). When the calcination temperature is 450 °C, the microstructure becomes powdery, the cement is mainly composed of MgO, and the flexural and compressive strengths are completely lost.

Improving Mechanical Properties of Autoclaved Aerated Concrete by Sugar Sediment

2013 ◽  
Vol 807-809 ◽  
pp. 1266-1269 ◽  
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.

Influence of MgCl2 Solution Concentration on Strength of Magnesium Oxychloride Cement Concrete

2012 ◽  
Vol 450-451 ◽  
pp. 791-795 ◽  
Author(s):  
Hong Xia Qiao ◽  
Yao Liu ◽  
Ming Ru Zhou ◽  
Hong Fa Yu ◽  
Jian Feng
Keyword(s):  
Solution Concentration ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Cement Concrete ◽  
X Ray ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Mgcl2 Solution ◽  
Scanning Electron ◽  
Oxychloride Cement

The molar ratio of MgO and MgCl2 affects prominently on the strength of Magnesium Oxychloride Cement Concrete. Different ratios were used to explore the optimum mixture proportion with the highest uniaxial compressive strength. The influence of the MgCl2 solution concentration is presented. XRD (X-ray diffraction) and SEM (scanning electron microscope) was used to analyze the micro-mechanism.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

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
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Phase Composition ◽  
Fly Ash ◽  
Industrial Waste ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

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.

Experimental Study on Desulfurized Gypsum Modified Magnesium Oxychloride Cement

2011 ◽  
Vol 236-238 ◽  
pp. 1554-1558
Author(s):  
Zhi Jie Zhang ◽  
Tao Li ◽  
Ping An Liu
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Abrasion Loss ◽  
Magnesium Oxychloride ◽  
Abrasive Tools ◽  
Magnesium Oxychloride Cement ◽  
Softening Coefficient ◽  
Oxychloride Cement

The influences of desulfurization gypsum on the properties of both Magnesium oxychloride cement (MOC) pastes and MOC abrasive tools were investigated in this study. By incorporating desulfurization gypsum in the MOC pastes, the compressive strength of MOC paste improved slightly. With 5% gypsum addition, the flexural strength of MOC pastes increased by 36%, the abrasion loss of MOC abrasive tools decreased by 35%, the strength softening coefficient greatly increased. The mechanism maybe due to the microstructure of the MOC pastes became more compact with gypsum adding, the rate of hydrolyzation reaction of MOC phases would be postponed.

Influence of Calcium Added Slag on the Strength and Water-Repellency of Magnesium Oxychloride Cement

2013 ◽  
Vol 278-280 ◽  
pp. 437-439
Author(s):  
Yu Jie Jin ◽  
Li Guang Xiao ◽  
Feng Luo
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Water Repellency ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Softening Coefficient ◽  
Oxychloride Cement

The influence of dosage of calcium added slag on the strength and water-repellency of Magnesium oxychloride cement was studied in this paper. The results indicated that the compressive strength of magnesium oxychloride cement enhanced while the flexural strength remained unchanged when the dosage of calcium added slag between 5%-30%. The compressive strength of magnesium oxychloride cement was 110.0 MPa when the dosage of Calcium added slag was 20%, which increased the strength of 17%. The calcium added slag significantly improved the water-repellency of Magnesium oxychloride cement. The softening coefficient of magnesium oxychloride cement was more than 0.82, and the highest is 1.07.

STUDY OF MECHANICAL PROPERTIES AND FRACTURE MODE OF ALUMINA-SILICON CARBIDE NANOCOMPOSITES

2012 ◽  
Vol 05 ◽  
pp. 551-558 ◽  
Author(s):  
A. RAHIMNEZHAD YAZDI ◽  
H.R. BAHARVANDI ◽  
H. ABDIZADEH ◽  
N. EHSANI
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Flexural Strength ◽  
Fracture Mode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sic Particles ◽  
Scanning Electron

In this study Al 2 O 3- SiC nanocomposites have been fabricated by mixing of alumina and silicon carbide nano powders, followed by hot pressing at 1700°C. The mechanical properties and fracture mode of Al 2 O 3- SiC nanocomposites containing different volume fractions (5, 10 and 15%) of nano scale SiC particles were investigated and compared with those of alumina. Al 2 O 3- SiC powders were prepared by planetary milling in isopropanol. Fracture mode of specimens was investigated by means of scanning electron microscopy. Nanocomposites were tougher than alumina when they were hot pressed at the same temperature, and the values of nanocomposite's flexural strength and hardness were higher than those of alumina. Flexural strength, hardness and fracture toughness of the nanocomposites increase by increasing the volume percent of SiC up to 10% and then decrease slightly. The Scanning electron microscopy observations showed that fracture mode changes from intergranular for alumina to transgranular for nanocomposites. Finally X-ray diffraction analysis couldn't detect any chemical reactions between Al 2 O 3 and SiC particles.

scholarly journals Low temperature preparation of α-tricalcium phosphate and its mechanical properties

2017 ◽  
Vol 11 (2) ◽  
pp. 100-105 ◽  
Author(s):  
Song Wang ◽  
Yaping Wang ◽  
Kangning Sun ◽  
Xiaoning Sun
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Tricalcium Phosphate ◽  
Annealing Temperature ◽  
Thermal Transformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Temperature Preparation ◽  
Scanning Electron ◽  
Temperature Preparation

In this work, ?-tricalcium phosphate (?-TCP) was successfully prepared by the thermal transformation of amorphous calcium phosphate (ACP) precursor. ?-cyclodextrin (?-CD) was used for preparation of ACP precursor and played an important role in designing its special structure. The phase composition and microstructures of the obtained ?-TCP at different annealing temperature were analysed by X-ray diffraction and scanning electron microscope, and confirmed that ?-TCP can be prepared at 650?C for 3 h using ACP as precursor, which is much lower than the phase transition temperature of ?-TCP. Mechanical properties were tested 24 h after mixing the obtained ?-TCP with 30 wt.% of deionised water. The compressive strength and the flexural strength were 26.4MPa and 12.0MPa, respectively. The flexural strength was higher than that of ?-TCP prepared by other methods.

TiCN-Based Cermets Strengthened with SiC Nano-Whiskers by Spark Plasma Sintering

2012 ◽  
Vol 512-515 ◽  
pp. 932-935
Author(s):  
Ying Peng ◽  
Zhi Jian Peng ◽  
Xiao Yong Ren ◽  
Hui Yong Rong ◽  
Cheng Biao Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Flexural Strength ◽  
Spark Plasma Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Addition Amount ◽  
Scanning Electron

TiCN-based cermets with different amounts of SiC nano-whiskers were prepared by spark plasma sintering. The microstructure and mechanical properties of the as-prepared cermets were investigated. X-ray diffraction revealed that there were no SiC peaks detected, turning out some peaks of new carbide and silicate hard phases. Scanning electron microscopy indicated that there were more and more pores in the cermets with increasing amount of SiC whisker added, and the fracture mechanism of the cermets was mainly inter-granular fracture. With increasing addition amount of nano-SiC whisker, the hardness and flexural strength of the cermets increased first and decreased then, presenting the highest hardness (2170 HV) and flexural strength (750 MPa), respectively, when the addition content of nano-whiskers is 2.5 wt%.

scholarly journals Compressive strength and microstructure of modified coffee exocarp cement-based composites

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9059-9074
Author(s):  
Zehua Zhu ◽  
Cheng Cheng ◽  
Debin Zhu ◽  
Dewen Liu ◽  
Yafei Zhang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Portland Cement ◽  
Vacuum Extraction ◽  
X Ray Diffraction ◽  
Extraction Technology ◽  
X Ray ◽  
Scanning Electron

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.

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