• 제목/요약/키워드: siliceous

검색결과 94건 처리시간 0.026초

규산질계 액상형 바탕강화재의 콘크리트 표층부 보강특성에 관한 기초적 연구 (A Foundational Study on Effect of Siliceous Sealer for Reinforcement of Concrete Surface Layer)

  • 최성민;곽규성;윤우옥;김상갑;오상근;안상덕
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
    • /
    • pp.671-676
    • /
    • 1998
  • This study deals with the effect on penetration properties of siliceous ion througth the mortar applicated by the waterproofing coating materials of siliceous seler liquid type. The tests of properties for reinforcing effect in mortar substrate surface layer are five kinds of water permeability, absorption, compressive strength, surface layer strength, pH content and chemical attack effect. Water permeability of mortar coated siliceous sealer in very than that of plane mortar. compressive strength of mortar coated siliceous sealer in larger than that of plane mortar about 10%.

  • PDF

Rheological, Mechanical and Structural Performances of Crushed Limestone Sand Concrete

  • Akrout, Khaoula;Mounanga, Pierre;Ltifi, Mounir;Jamaa, Nejib Ben
    • International Journal of Concrete Structures and Materials
    • /
    • 제4권2호
    • /
    • pp.97-104
    • /
    • 2010
  • The crushed limestone sand is an abundant material in Tunisia, which induces many environmental problems. Indeed, available stocks of siliceous sand drastically decrease because of its massive use in hydraulic concrete. Some recent research works, carried out in Tunisia, concluded that crushed limestone sand may be used in concrete manufacture instead of siliceous sand traditionally used. In this context, an experimental study was achieved in order to quantify the influence of a partial or total substitution of siliceous sand by crushed limestone sand on hydraulic concrete performances. Preliminary chemical and physical tests on crushed sand indicated that it presented the minimum requirement for its use as aggregate in hydraulic concrete. 79 concretes were then prepared with siliceous sand, crushed limestone sand and a mix of the two sands. Their slump value and compressive strengths were measured on plain concretes. Complementary structural tests on reinforced concrete beam were also performed. The results proved that crushed limestone sand concretes showed workability and mechanical performances closed to those of siliceous sand concretes.

규산질비분말혼합시멘트계도포방수재료를 도포한 몰탈 조직에서의 결정생성 평가 (Estimation of Crystal Production in Microstructure of Mortar Cooated with Siliceous Slurry Coatings)

  • 오상근
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 1993년도 봄 학술발표회 논문집
    • /
    • pp.89-92
    • /
    • 1993
  • This paper deals with the effect of siliceous slurry coatings on mortar microstructure under a damp environment. For estimation on effect of siliceous slurry coating, microstructure of coated mortar was observed through SEM. Crystal production in mivrosturcture of coated mortar was periodically increased, and more produced in mortar of high water-cement ratios. And they were generated mainly in mortar ranging from the surface to the inside about 2.5 or 3mm deep.

  • PDF

폭로환경하에서 규산질미분말혼합 시멘트계 도포방수재가 바탕모르터의 투수성과 세공구조에 미치는 영향 (Properties of Water Permeability and Porosity of Cement Mortar Substrate Coated with Siliceous Slurry Coating under Exposure Enviorment)

  • 김형무;오상근
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 1996년도 가을 학술발표회 논문집
    • /
    • pp.175-182
    • /
    • 1996
  • This paper deals with the properties of water permeability and porosity of cement mortar substrate coated with siliceous slurry coating under the exposure environment. Conditions of exposure enviornment are four kinds of in constant temperature water and humidity box, in indoor and outdoor exposure. Coated mortar substrate was expected continually increase in water and humidity condition, but was not in dry condition. Watertightness effect of siliceous coating was better in the condition of humidity then the dry condition, and the pore volume was decreased in that condition.

  • PDF

석영미분말의 입자크기가 UHPC의 유동성 및 강도에 미치는 영향 (Effect of siliceous powder's particle size on the workability and strength of UHPC)

  • 강수태;박정준;류금성;고경택;김성욱;이장화
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
    • /
    • pp.441-444
    • /
    • 2008
  • 본 연구에서의 초고성능 콘크리트(Ultra High Performance Concrete, UHPC)는 모래, 시멘트, 실리카퓸, 석영미분말, 강섬유 및 고성능감수제 등으로 구성되며, 평균입경 약 0.5mm이하의 아주 작은 입자들로 구성된다. 일반적으로 석영미분말는 일정크기 이상의 공극을 메움으로써 물리적 성능개선의 효과가 있으며 또한 높은 $SiO_2$함량을 가지므로 고온 또는 고압의 양생조건에서 시멘트 수화물과의 화학반응을 통해서도 성능 향상효과가 있는 것으로 알려져 있다. 본 연구에서는 상압, $90^{\circ}C$ 증기양생 조건에서 석영미분말의 입자크기가 초고성능 콘크리트의 역학적 특성에 어떠한 영향을 미치는지에 대해 알아보고자 하였으며, 평가항목으로는 굳지 않은 상태에서의 유동성과 굳은 상태에서의 압축강도, 극한변형률, 탄성계수 및 휨강도를 평가하였다. 석영미분말의 입경크기의 영향은 약 $2{\mu}m$에서 $26{\mu}m$까지의 범위에서 고려하였으며, 입경 크기가 작을수록 유동성 및 강도특성이 모두 향상되는 것으로 나타났다.

  • PDF

규산질계 분말형 도포방수재의 내투수성 성능평가 연구 (Hydrostatic Pressure Resistance Performance Testing of Cement Mixed Siliceous Powder Waterproofing Coationgs)

  • 박소영;권시원;김수연;김병일;오상근
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2018년도 추계 학술논문 발표대회
    • /
    • pp.31-32
    • /
    • 2018
  • Lately, cement mixed siliceous powder waterproofing coating has been used as a waterproofing material in the wet environment condition of an underground concrete structure. Underground is exposed to environmental influences such as pressure of ground water, pressure of soil. However, the quality standard for pressure (water pressure, earth pressure) is not specified in the specification of the cement mixed siliceous powder waterproofing coating. Therefore, in this study, the permeability test was carried out based on the assumption that the durability should be verified in consideration of the environmental aspects of the material in actual field. As a result of the test, the permeability was generated from the inorganic single type material, but it was caused by the sealing failure and the test error, and the permeability was not generated in most of the materials. The results of this study will be analyzed by reviewing the physical properties of the material, and the research direction will be resumed.

  • PDF

Determination of fracture toughness in concretes containing siliceous fly ash during mode III loading

  • Golewski, Grzegorz Ludwik
    • Structural Engineering and Mechanics
    • /
    • 제62권1호
    • /
    • pp.1-9
    • /
    • 2017
  • This paper describes laboratory tests carried out to evaluate the influence of class F fly ash (FA) on fracture toughness of plain concretes, specified at the third model fracture. Composites with the additives of: 0%, 20% and 30% siliceous FA were analysed. Fracture toughness tests were performed on axial torsional machine MTS 809 Axial/Torsional Test System, using the cylindrical specimens with dimensions of 150/300 mm, having an initial circumferential notch made in the half-height of cylinders. The studies examined effect of FA additive on the critical stress intensity factor $K_{IIIc}$. In order to determine the fracture toughness $K_{IIIc}$ a special device was manufactured.The analysis of the results revealed that a 20% FA additive causes increase in $K_{IIIc}$, while a 30% FA additive causes decrease in fracture toughness. Furthermore, it was observed that the results obtained during fracture toughness tests are convergent with the values of the compression strength tests.

규산질미분말혼합시멘트계도포방수재료가 습윤환경하의 콘크리트의 미세조직에 미치는 영향 (Effect of Siliceous Slury Coating on Microstructure of Concrete under Damp Environment)

  • 오상근
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 1992년도 가을 학술발표회 논문집
    • /
    • pp.1-4
    • /
    • 1992
  • This paper deals with the effect of siliceous slurry coating on concrete microstructure under damp environment. This material is mixed inorganic powder consisted of silica, cement and fine sand and water. Water pressure was given on the coated surface of concrete. for estimation on effect of siliceous slurry coating, microstructure of coated concrete was observed through SEM, and chemical components of crystals were analyzed with X-ray diffraction and EDX. A number of needle and fibrous crystals were produced in microstructure. And based on X-ray diffraction and EDX, needle crystal mainly consist of Al, Si, and Ca, and it is concluded to be ettringite. Fibrous crystals consist of Ca and Si, and it to be calcium silicate hydrate.

  • PDF

콘크리트 표층부 내구성 증진 및 성능개선을 위한 규산질계 액상형 도포 방수재의 성능 평가 연구 (A Study on the Concrete Surface of Durability Advancement and Performance Improvement for the Siliceous Liguid Type of Spread Waterproofing Material)

  • 김진성;송제영;박진상;오상근
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
    • /
    • pp.29-32
    • /
    • 2005
  • It is recognised that a permeability waterproof agent have been extensively used for concrete, in these days. In present paper shows effective practical scheme of a permeability waterproof agent in construction market that is to develope durability of concrete structure as apply to job site through the examination physical and chemical property of a permeability waterproof agent. It is indentified that can be maintain waterproofing performance, moreover it makes satisfactory result of permeation resistance as applying siliceous waterproof agent.

  • PDF

산화물 고체전해질의 입계전도 (Grain-Boundary Conduction in Solid Oxide Electrolyte)

  • 이종흔
    • 한국세라믹학회지
    • /
    • 제44권12호
    • /
    • pp.683-689
    • /
    • 2007
  • Grain-boundary conduction in the fluorite-structure solid oxide electrolytes such as acceptor-doped zirconia and ceria were reviewed. The siliceous impurity, even several hundreds ppm, affects the ionic conduction across grain boundary to a great extent. Various approaches to improve grain-boundary conduction in fluorite-structure oxide electrolytes have been investigated, which include (1) the scavenging of siliceous phase by the reaction with second phase, (2) the gathering of intergranular siliceous phase into a discrete configuration and (3) the dewetting of intergranular liquid phase by post-sintering heat treatment.