scholarly journals The Mechanical Properties and Microstructure of Reticulated Red Clay-Sand Mixture Using X-Ray Diffraction

2021 ◽  
Vol 2083 (2) ◽  
pp. 022081
Author(s):  
Yuxin Zhang ◽  
Jianzhong Li ◽  
Chuang Zhang

Abstract To assess the behavior of Reticulated Red Clay (RRC)-sand mixtures, a series of laboratory tests were performed on RRC-sand mixtures in which the weight ratio of sand ranging from 0% to 80%. Compaction test and direct shear test were conducted to evaluate the compactness of mixtures. The threshold sand content for the change of the mechanical properties of the mixture is 50%, and the mixture at this time has the densest structure. Oedometer test to the mixture indicate that the coefficient and compression modulus of it are only related to the ratio of its components. As the sand content in the mixture increases, the phenomena that the clay particles enclosing the sand particles and filling into the gaps of particles make the mixture denser. During the same time, there is a phenomenon of internal friction between sand particles caused by the inadequate wrapping of clay particles. Combined with the results of scanning electron microscopy and optical microscopy, the appearance of these phenomena and the transition process of the structure of the mixture from the clay structure to the sand structure were confirmed.

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongfang Qian ◽  
Zhen Zhang ◽  
Laijiu Zheng ◽  
Ruoyuan Song ◽  
Yuping Zhao

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.


2008 ◽  
Vol 8 (4) ◽  
pp. 1937-1941
Author(s):  
R. Barbosa ◽  
E. M. Araújo ◽  
T. J. A. Melo ◽  
E. N. Ito ◽  
E. Hage

High density polyethylene/Brazilian clay nanocomposites were prepared by the melt intercalation technique. A montmorillonite sample from Boa Vista/PB, Northeast of Brazil, was organically modified with esthearildimethylammonium chloride (Praepagen WB) quaternary ammonium salt. The unmodified and modified clays with the quaternary ammonium salt were introduced in 1, 2, 3 and 5 wt% in a PE polymer matrix. The dispersion analysis and the interlayer distance of the clay particles were obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The mechanical properties of tensile and the flammability of the nanocomposites were studied. In general, the mechanical properties of the systems presented superior values compared to the matrix. The systems showed a reduction on the burning rate, indicating that the flammability resistance of nanocomposites was improved.


2021 ◽  
Vol 11 (16) ◽  
pp. 7252
Author(s):  
Dazhi Wu ◽  
Keyu Chen ◽  
Zilong Zhang ◽  
Lifu Chang

The ordinary Portland cement (OPC)-based solidification process is used extensively to reinforce soils due to its available and good bonding properties. Alternative products are used in cementitious materials to enhance the strength and to reduce OPC consumption. In this study, the effect of additive type and mass fraction on the microstructure and mechanical properties of solidified sandy silt are investigated. There are four types of additives (gypsum, lime, clay particles, and fly ash) at mass fractions of 2, 3, and 4% that are considered in order to study their mechanical properties (unconfined compression, indirect tensile, flexural strength, and compressive resilient modulus) at 7, 14, 28, 60, and 90 days. The optimal contents of additive gypsum, clay particles, and fly ash are determined to be 2%, 4%, and 4%, respectively. Such improvement of additive-modified OPC solidified sandy silt is due to the formation of the crystalline compound or the gradation composition improvement via field emission scanning electron and X-ray diffraction analysis.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Lijie Chen ◽  
Xuejun Chen ◽  
Xin Yang ◽  
Pengyan Bi ◽  
Xiang Ding ◽  
...  

The influence of precipitated calcium carbonate on the strength and microstructure of red clay was studied. Precipitated calcium carbonate was added to red clay at ratios of 0%, 5%, 10%, 15%, and 20%. Shear tests were carried out on the samples to observe the effect of calcium carbonate on the mechanical properties of red clay. The results showed that, with increasing calcium carbonate content, the strength of red clay first decreased and then increased. The maximum strength was obtained for the sample with 20% calcium carbonate. Scanning electron microscopy (SEM) was used to observe the changes in microstructure caused by addition of calcium carbonate. The pores and cracks analysis system (PCAS) was used to quantitatively characterize the microstructure changes detected in SEM images. The addition of calcium carbonate decreased the pore area and increased the total number of pores of red clay. The incorporation of calcium carbonate caused the red clay particles to agglomerate. The higher the calcium carbonate content, the stronger the agglomeration of red clay particles in the soil samples.


2021 ◽  
Vol 19 (11) ◽  
pp. 40-46
Author(s):  
Manar Ghyath Abd-Almutalib Al-Mosawy ◽  
Zeyad Kadhim Oleiwi

Biodegradable polymers, like Polycaprolactone (PCL), have recently received a lot of attention in the science establishment because of the growing global interest in non - petroleum-based polymeric materials. 3-amino - 4 - ((3-hydroxyphenyl) diazenyl) - N(pyrimidine-2-yl) benzenesulfonamide (AZO) one of the organic materials used to reconfigure natural clay (sodium montmorillonite). The clay particles were modified by stirring them in an aqueous medium of AZO-MMT, which increased the wavelength from 1.27 to 2.04 nm. The reconfigured clay would have been used to make PCL/corn-starch mixture nanocomposites. They were created by combining 0.5–5% AZO-MMT. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were utilized to characterize the interaction of the modifier in the clay layer. The nanocomposites were prepared by solution casting method the reconfigured clay and a PCL/corn-starch mixture at a weight ratio of 80/20, which leads to an increase in the scope of tensile strength which that considers the biggest blend. The results of survey electron microscopy, transmission electron microscopy, and XRD was proved the creation of nanocomposites materials. Additionally, that PBS/corn-starch reconfigured clay nanocomposites exhibit that superior thermal stability significantly and a great increase over the PCL/corn-starch mixture.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lina Wang ◽  
Zhiyu Weng ◽  
Qiang Liu ◽  
Tianliang Wang ◽  
Xuemin Pan ◽  
...  

The traditional treatment of red clay using inorganic materials leads to many serious environmental problems. The study investigates the mechanical properties of red clay using an environmental-friendly material—xanthan gum—through confined compression, direct shear, and scanning electron microscope tests. At the macroscale, xanthan gum content and curing age had obvious effects on the compressibility, presenting the treated red clay was in the category of low compressibility which gradually increased when xanthan gum content exceeded 1.5%. The xanthan gum content and curing age also had significant influences on the cohesion but not on the internal friction angle. The shear strength of red clay can be improved by increasing the cohesion without obviously changing the friction characteristics. After curing for 28 days, the cohesion and internal friction angle of 2.0% xanthan gum-treated soil were effectively improved to 170.44 kPa and 20.56°, which were increased by 69.79% and 9.36°, respectively, compared with untreated red clay. Microscopic analysis indicated that the strengthening mechanism by xanthan gum was derived from changing the arrangement characteristics of soil particles and forming hard biopolymer-red clay matrices. The proper xanthan gum can effectively wrap clay particles and fill pore spaces. However, the extensive stacking of gels would also reduce the effective connection of clay particles and produce local weak points in the soil, resulting in attenuation of mechanical properties. This study enriches the treatment measure of red clay and provides beneficial experiences for biopolymer application on special clay.


Author(s):  
Isaac Iglesias ◽  
Mayra Jiménez ◽  
Andrea M. Gallardo ◽  
Edward E. Ávila ◽  
Vivian Morera ◽  
...  

In this work, we report the mechanical properties of an alternative material based on a mixture of natural clay and ferruginous sand in pellet form for CO2 capture. These raw materials were collected from Ecuador, and they contain iron and titanium oxides from volcanic origin. To evaluate the effect of the sand content on the mechanical properties of pellets, the samples were manually prepared with 0 (control sample), 15, and 25 wt.% sand contents and analyzed using free-fall drop impact and uniaxial compression tests. The uniaxial compression test was carried out under three conditions: using sieved sand, using sand without sieving, and under wet conditions. The sand contents caused the drop number to decrease in the free-fall drop impact test. From the uniaxial compression test, the compressive strength, elastic modulus, and toughness were calculated. The elastic modulus showed a better performance for samples with lower porosity. The compressive strength demonstrated higher values for samples with 15 wt.% sand contents than for samples with the other sand contents. The toughness values did not significantly change. It was evidenced that the porosity, mineral composition, and humidity exerted an influence during the mechanical tests. The mineral phases were analyzed by X-ray diffraction, and quantitative analysis based on whole-powder-pattern fitting revealed that the iron and titanium oxide contents increased as the concentration of sand in the pellets increased.


2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.


2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 753
Author(s):  
M. Baibarac ◽  
A. Nila ◽  
I. Smaranda ◽  
M. Stroe ◽  
L. Stingescu ◽  
...  

In this work, new films containing composite materials based on blends of thermoplastic polymers of the polyurethane (TPU) and polyolefin (TPO) type, in the absence and presence of BaTiO3 nanoparticles (NPs) with the size smaller 100 nm, were prepared. The vibrational properties of the free films depending on the weight ratio of the two thermoplastic polymers were studied. Our results demonstrate that these films are optically active, with strong, broad, and adjustable photoluminescence by varying the amount of TPU. The crystalline structure of BaTiO3 and the influence of thermoplastic polymers on the crystallization process of these inorganic NPs were determined by X-ray diffraction (XRD) studies. The vibrational changes induced in the thermoplastic polymer’s matrix of the BaTiO3 NPs were showcased by Raman scattering and FTIR spectroscopy. The incorporation of BaTiO3 NPs in the matrix of thermoplastic elastomers revealed the shift dependence of the photoluminescence (PL) band depending on the BaTiO3 NP concentration, which was capable of covering a wide visible spectral range. The dependencies of the dielectric relaxation phenomena with the weight of BaTiO3 NPs in thermoplastic polymers blends were also demonstrated.


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