• Title/Summary/Keyword: mercury porosimetry

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Optimal Use of MSWI Bottom Ash in Concrete

  • Zhang, Tao;Zhao, Zengzeng
    • International Journal of Concrete Structures and Materials
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    • v.8 no.2
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    • pp.173-182
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    • 2014
  • An experimental investigation was carried out to evaluate the mechanical properties of concrete mixtures in which coarse aggregate was partially (30, 50 or 70 %) replaced with pre-washed municipal solid waste incineration (MSWI) bottom ash. Results indicated that bottom ash reduced the compressive strength, elastic modulus, and levels of heavy metals in leachate when used as a replacement for gravel, and that the maximum amount of MSWI bottom ash in concrete should not exceed 50 %. To analyze the effect mechanism of bottom ash in concrete, the degree of hydration and the following pozzolanic reaction characterized by the pozzolanic activity index, and the porosity distribution in cement mortar. The study indicates that improved properties of concrete are not solely later strength gain and reduced levels of heavy metals in leachate but also the progression of pozzolanic reactions, where a dense structure contains a higher proportion of fine pores that are related to durability.

Characteristic of Pore Structure and Chloride ion Diffusion in Concrete Containing GGBF (고로슬래그미분말 혼합 콘크리트의 공극구조 및 염소이온 확산특성)

  • 문한영;김홍삼;최두선
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.365-368
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    • 2002
  • This paper considers transference number in calculating diffusion coefficient of chloride ions of concrete and mercury intrusion porosimetry to investigate the volume and distribution of pore size, respectively, analyzing and discussing the property of resistance to chloride ion of concrete with granulated blast furnace slag. The experimental results show that the diffusion coefficient of chloride ion decreases with the rise of quantity of granulated blast furnace slag and pore structure of concrete with granulated blast furnace slag is different from that of OPC concrete. And from the results of regression analysis, the result showed that the diffusion coefficient of chloride ions is affected by capillary pore above 50nm.

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Pore Structure and Permeability of Concrete Containing Pozzolanic Materials (포졸란 함유 콘크리트의 공극구조와 투과특성)

  • 김재신;소형석;소승영;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.159-162
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    • 1999
  • The paper presents results of an investigation on the permeability characteristics and pore structure of concrete containing different levels of fly ash, silica fume, or blast furnace slag. The total cementitious content was 351kg/㎥, and the water/cementitious materials ratio was 0.55. The porosity and pore structure of representative pastes of the matrix were measured using mercury intrusion porosimetry, and the permeability characteristics of concrete were also determined by water and oxygen permeability, chloride ion penetration. The results show that significant reduction in permeability of concrete containing pozzolanic materials due to formation of a discontinuous macro-pore system which inhibits flow. And, the permeability of concrete and pore structure(capillary porosity or total porosity) shows linear relationship.

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Characterization of nano-fiber web structures using a morphological image processing

  • Kim, Jooyong;Lee, Jung-Hae
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.100-100
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    • 2003
  • An image processing algorithm has been developed in order to analyze the nanofiber web images obtained from a high magnification microscope. It has been known that precise pore detection on thick webs is extremely difficult mainly due to lack of light uniformity, difficulty of fine focusing and translucency of nanofiber web. The pore detection algorithm developed has been found to show excellent performance in characterizing the porous structure, thus being a promising tool for on-line quality control system under mass production. Since the images obtained from an optical microscope represent only web surface, a scale factor has been introduced to estimate the web structure as a whole. Resulting web structures have been compared to those by mercury porosimetry, especially in pore size distribution. It has been shown that those two structures have a strong correlation, indicating that scaling of a single layer web structure can be an effective way of estimating the structure of thick fiber webs.

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The utilization of waste seashell for high temperature desulfurization

  • Kim, Young-Sik;Kim, Taek-Geun;Sim, Eon-Bong;Seo, Jeong-Min
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.12a
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    • pp.66-71
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    • 2005
  • The waste seashells were used for the removal of hydrogen sulfide from a hot gas stream. The sulphidation of waste seashells with $H_2S$ was studied in a thermogravimetric analyzer at temperature between 600 and 800$^{\circ}C$. The desulfurization performance of the waste seashell sorbents was experimentally tested in a fixed bed reactor system. Sulfidation experiments performed under reaction conditions similar to those at the exit of a coal gasifier showed that preparation procedure and technique, the type and the amount of seashell, and the size of the seashell affect the $H_2S$ removal capacity of the sorbents. The pore structure of fresh and sulfided seashell sorbents was analyzed using mercury porosimetry, nitrogen adsorption, and scanning electron microscopy.

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Reaction of $H_2S$ with Sorbents of Waste Seashell

  • Kim, Young-Sik;Kim, Taek-Gyun;Lee, Yong-Du;Shim, Eon-Bong;Jung, Jong-Hyeon
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.06a
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    • pp.378-380
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    • 2005
  • The waste seashells were used for the removal of hydrogen sulfide from a hot gas stream, The sulphidation of waste seashells with H$_2$S was studied in a thermogravimetric analyzer at temperature between 600 and 800${\circ}$C . The desulfurization performance of the waste seashell sorbents was experimentally tested in a fixed bed reactor system. Sulfidation experiments performed under reaction conditions similar to those at the exit of a coal gasifier showed that preparation procedure and technique, the type and the amount of seashell, and the size of the seashell affect the H2S removal capacity of the sorbents. The pore structure of fresh and sulfided seashell sorbents was analyzed using mercury porosimetry, nitrogen adsorption, and scanning electron microscopy.

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A Study on the Permeabilities of Concretes Containing Silica Fume (실리카 흄을 혼입한 콘크리트의 투과특성에 관한 연구)

  • 형원길;장효식;소형석;소승영;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.443-448
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    • 1999
  • Tests have been carried out on four concrete containing different levels of silica fume to measure their permeability coefficient using water and oxygen, chloride ion. The total cementitious content was 351kg/㎥, and the water/cementitious materials ratio was 0.55. The results show that a dramatic reduction in permeability of concrete containing silica fume occurs due to formation of a discontinuous macro-pore system which inhibits flow. Porosity estimates from mercury-intrusion porosimetry are used to develop an explanations for the water and air permeability reduction. And, results of the rapid permeability test showed that the resistance of concrete to the penetration of chloride ions increases significantly as a contents of silica-fume is increased. The current intensity passing through the concrete containing silica fume is presented from 664C to 2166C.

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A Study on the Drain Performance & Pore Structure of Cellular Mortar which Drain Material of the Composite Lining Method (Composite 라이닝 공법의 배수공 재료인 경량기포모르타르의 공극구조와 배수성능에 대한 고찰)

  • Choi, Hee-Sup;Ma, Sang-Joon;Lee, Heung-Soo;Seo, Shin-Seok
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.425-426
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    • 2009
  • As a result of the Mercury Intrusion Porosimetry(MIP) test, FCR Batch with the continuous voids in excellent permeability is appeared with the Cellular Mortar that is most suitable which Drain Material of the Composite Lining Method.

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Oil Adsorption of Exfoliated Graphite Prepared by Direct Reaction between $SO_3$ Gas and Graphite

  • Lee, Beom-Jae;Kwon, Young-Bae
    • Carbon letters
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    • v.2 no.1
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    • pp.55-60
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    • 2001
  • Graphite intercalation compounds (GIC) were prepared by direct reaction of $SO_3$ gas with flake graphite. The intercalated $SO_3$ molecules were ejected by rapid heating to $950^{\circ}C$ under an oxidizing atmosphere for about 1 minute, resulting in surprisingly high expansion in the direction of c-axis. The characteristics of the micro-structure and pore size distribution were examined with a SEM and mercury intrusion porosimetry. The XRD analysis and spectroscopic analysis were used for the identification of the graphite and surface chemistry state. The pore size distribution of the exfoliated graphite (EG) was a range of $1{\sim}170{\mu}m$. The higher expanding temperature the higher expanded volume, so oil sorption capacities were 58.8 g of bunker-C oil and 34.7 g of diesel oil per 1 g of the the EG. The sorption equilibrium was achieved very rapidly within several minutes. As the treatment temperature increases, bulk density decreases.

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A Study of Chloride Diffusion Coefficient and Microstructure of High Fluidity Concrete Using Limestone Powder (석회석 미분말을 활용한 고유동 콘크리트의 염소이온 확산계수와 미세공극에 관한 연구)

  • Choi, Yun-Wang;Jeong, Jae-Gwon;Kim, Kyung-Hwan;Ha, Sang-Woo;Ryu, Deuk-Hyun;Oh, Sung-Rok
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.199-200
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    • 2010
  • This paper was estimated the diffusion coefficient through the chlorine ion diffusion coefficient of the high fluidity concrete using the limestone powder. Also, the micro void of high fluidity concrete examined according to the mixing ratio of the limestone powder by the mercury intrusion porosimetry.

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