State of a Bentonite Barrier after 8 Years of Heating and Hydration in the Laboratory

AbstractThe conditions of the bentonite in an engineered barrier for HLW disposal have been simulated in a laboratory test. Six cylindrical blocks of bentonite compacted at a dry density of 1.64 g/cm3 were piled up in a hermetic Teflon cell. The total length of clay inside the cell was 60 cm. The bottom surface of the bentonite was heated at 100°C while the top surface was injected with granitic water. The duration of the test was 7.6 years. The water intake was measured during the test and, at the end, the cell was dismounted and the dry density, water content, specific surface area, mineralogy, geochemistry and swelling capacity of the clay were measured in different sections along the blocks. The material used in this test is the FEBEX bentonite.

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Hydraulic/Mechanical Modeling of Smectitic Materials for HMC Analytical Evaluation of the Long Term Performance of TRU Geological Repository

ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B ◽

10.1115/icem2011-59090 ◽

2011 ◽

Cited By ~ 5

Author(s):

Ichizo Kobayashi ◽

Hitoshi Owada ◽

Tomoko Ishii

Keyword(s):

Specific Surface ◽

Water Content ◽

Surface Area ◽

Specific Surface Area ◽

Dry Density ◽

Compression Stress ◽

Mechanical Modeling ◽

Long Term Performance ◽

Term Performance

Aiming at evaluation of the long term performance of transuranic (TRU) geological repositories, the hydraulic/mechanical/chemical (HMC) analysis method has been studied. In this phase of research (four years) the hydraulic/mechanical modeling of smectitic materials for HMC analyses has been studied. In this paper, new experimental methods for investigation of the hydraulic/mechanical behavior of smectitic materials were developed. For hydraulic modeling, the measurement method of the specific surface area of compacted smectitic materials was developed using X-ray diffraction (XRD). The results of the method were applied to the Kozeny-Carman law. Since the specific surface area represents the microstructure of smectitic materials such as the degree of swelling, it was found that the Kozeny-Carman law using measured specific surface area of compacted smectitic materials was useful in evaluating the hydraulic performance of smectitic materials. Moreover, since the Kozeny-Carman law can take the alteration of content of pore water into consideration by not only a coefficient of viscosity but also by changes in specific surface area, the Kozeny-Carman law will be more suitable to chemical and mechanical couple analyses than the ordinary Darcy’s law. For the mechanical modeling, the procedure of one dimensional exhausting compression test was developed. The tests gave the dry density and compression stress relation in the state of full-saturation of smectitic materials with varying water content. The relations between the dry density and compression stress in the state of fully-saturation were termed fully saturation lines. The group of isograms of degree of saturation and water content were also given with this test. It was found that the fully-saturation line is consistent with swelling deformation-pressure relation in the equilibrium state. The results indicated that the swelling deformation-pressure relation does not depend on the saturation manner, such as the injecting of water or exhausting of air due to compression. There will be, therefore, the possibility that the swelling deformation-pressure relation will be state functions and independent on the stress history. The fully-saturation line was compared with the equilibrium swelling pressure and dry density relation calculated from chemical potential by Sato (2008). Both were consistent with each other. It was found that the swelling behavior of smectitic materials can be treated as a state function in the mechanical analysis.

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Comparative Analysis on Chemical Composition and Charcoal Characterization of Two Miscanthus Species

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1265 ◽

2011 ◽

Vol 415-417 ◽

pp. 1265-1272

Author(s):

Wen Biao Zhang ◽

Wen Zhu Li ◽

Bing Song Zheng

Keyword(s):

Chemical Composition ◽

Specific Surface ◽

Water Content ◽

Surface Area ◽

Specific Surface Area ◽

Ph Value ◽

Perennial Grass ◽

Water Extract ◽

Carbonization Temperature ◽

Hot Water

Miscanthus is a highly productive, rhizomatous, C4 perennial grass that should be considered as an excellent active carbon precursor. This paper compares the charcoal characterization and chemical composition between M. sinensis and M. floridulus. Species differed in water content, hot water extract, 1% NaOH extract, organic solvent extract, cellulose, lignin and ash. Carbonization temperatures have effects on charcoal yields of Miscanthus, which ranged from 23.5% to 48.0% for M. sinensis and 11.3% to 37.2% for M. floridulus. Water content, charcoal density, pH value, and specific surface area of charcoal characterization varied between two species of Miscanthus. The specific surface area increased with the increase of carbonization temperature. The highest specific surface area of M. sinensis and M. floridulus was 351.74 m2g−1and 352.74 m2g−1, respectively, when the carbonization temperature was 800°C.

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The Effect of the Limestone on the Strength of the Foam Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1058.145 ◽

2014 ◽

Vol 1058 ◽

pp. 145-148

Author(s):

Xin Gang Yu ◽

Lu Hu ◽

Chao Gao ◽

Guo Lin Wu

Keyword(s):

Compressive Strength ◽

Flexural Strength ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Great Influence ◽

Experimental Results ◽

Dry Density ◽

Foam Concrete ◽

Heat Preservation

The effect of the limestone on the strength of the foam concrete is studied in this paper. The dry density of the foam concrete used in this experiment is 500 kg/m3, which is largely used in foam concrete for heat preservation in building. The experimental results reveal that the content of the limestone has great influence on the 3 d, 7 d and 28 d compressive strength and flexural strength of the foam concrete, but the fineness of the limestone has little influence on the 3 d, 7 d and 28 d compressive strength and flexural strength of the foam concrete, when the specific surface area is in the range of 210 cm2/g-440 cm2/g.

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Pengaruh Ukuran Serbuk Pada Aktivasi Tanah Liat Dari Tanak Awu Terhadap Daya Adsorpsinya Pada Pemurnian Minyak Goreng Bekas

Hydrogen: Jurnal Kependidikan Kimia ◽

10.33394/hjkk.v2i2.660 ◽

2014 ◽

Vol 2 (2) ◽

pp. 216

Author(s):

Baiq Asma Nufida ◽

Nova Kurnia ◽

Yeti Kurniasih

Keyword(s):

Specific Surface ◽

Water Content ◽

Adsorption Capacity ◽

Surface Area ◽

Specific Surface Area ◽

Oil Quality ◽

Acid Number ◽

Peroxide Number ◽

Natural Clay ◽

Cooking Oil

This research was aimed to get the effect of particel size of activated natural clay from Tanak Awu to their adsorption capacity for increase reused cooking oil quality. At previous research we done the activation of natural clay using acid (HCl) and got an optimal concentration of acid at 1 molar. Natural clay was grinding until particel size at 50 mesh, 60 mesh and 100 mesh then it was characterized in specific surface area by methylen blue methods and also acidity surface by acid base titration. Then activated natural clay was applied for purifying reused cooking oil by analyzing water content, acid number and peroxide number. The result showed that there are the effect of particel size of natural clay to acidity surface and specific surface area. While the adsorption capacity of natural clay on purifying reused cooking oil got that optimal particel size of activated natural clay at 60 mesh which getting the decrease of water content, acid number and peroxide number by following reach was 89,13%, 58,61% and 60,52%.

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