• Title/Summary/Keyword: blended cement concrete

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Application of Mass Concrete Exposed to Marine Environment (염해환경에 노출된 매스콘크리트의 시공)

  • Kim Dong Seok;Park Sang Joon;Shin Hong Chol;Yoo Jae Kang
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.487-490
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    • 2005
  • This study was performed to investigate the effect of ternary blended cement concrete mixed with slag cement and fly ash on the compressive strength, the resistance to chloride ion penetration and reduction of hydration heat. Each performance of ternary blended cement concrete compared with binary blended cement concrete and ordinary portland cement concrete. As a result, it was concluded that ternary blended cement concrete is suitable to mass concrete under marine environment.

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Influence of supplementary cementitious materials on strength and durability characteristics of concrete

  • Praveen Kumar, V.V.;Ravi Prasad, D.
    • Advances in concrete construction
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    • v.7 no.2
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    • pp.75-85
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    • 2019
  • The present study is focused on the mechanical and durability properties of ternary blended cement concrete mix of different grades 30 MPa, 50 MPa and 70 MPa. Three mineral admixtures (fly ash, silica fume and lime sludge) were used as a partial replacement of cement in the preparation of blended concrete mix. The durability of ternary blended cement concrete mix was studied by exposing it to acids HCl and $H_2SO_4$ at 5% concentration. Acid mass loss factors (AMLF), acid strength loss factor (ASLF) and acid durability factor (ADF) were determined, and the results were compared with the control mix. Chloride ions penetration was investigated by conducting rapid chlorination penetration test and accelerated corrosion penetration test on control mix and ternary blended cement concrete. From the results, it was evident that the usage of these mineral admixtures is having a beneficiary role on the strength as well as durability properties. The results inferred that the utilization of these materials as a partial replacement of cement have significantly enhanced the compressive strength of blended concrete mix in 30 MPa, 50 MPa and 70 MPa by 42.95%, 32.48% and 22.79%. The blended concrete mix shown greater resistance to acid attack compared to control mix concrete. Chloride ion ingress of the blended cement concrete mix was low compared to control mix implying the beneficiary role of mineral admixtures.

Sulfate and Freeze-thaw Resistance Characteristic of Multi-component Cement Concrete Considering Marine Environment (해양환경을 고려한 다성분계 시멘트 콘크리트의 황산염 및 동결융해 저항 특성)

  • Kim, Myung-Sik;Beak, Dong-Il;Kang, Jun-Ho
    • Journal of Ocean Engineering and Technology
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    • v.26 no.3
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    • pp.26-32
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    • 2012
  • Recently, concrete using multicomponent blended cement has been required to increase the freeze-thaw and sulfate resistances of concrete structures exposed to a marine environment. Thus, the purpose of this study was to propose the use of concrete containing multicomponent blended cement as one of the alternatives for concrete structures exposed to a marine environment. For this purpose, batches of concrete containing ordinary portland cement (OPC), binary blended cement (OPC-G, G: ground granulated blast slag), ternary blended cement (OPC-GF, F: fly ash), and quaternary blended cement (OPC-GFM, M: mata-kaolin) were made using a water-binder ratio of 50%. Then, the durability levels, including thesulfate and freeze-thaw resistances, were estimated for concrete samples containing OPC, OPC-G, OPC-GF, and OPC-GFM. It was observed from the tests that the durability levels of the concrete samples containing OPC-G and OPC-GF were found to be much better than that of the concrete containing OPC. The optimum mixing proportions were a40% replacement ratio of ground granulated blast slag for the binary blended cement and a30% replacement ratio of ground granulated blast slag and 10% fly ash for the ternary blended cement.

Prediction of compressive strength of slag concrete using a blended cement hydration model

  • Wang, Xiao-Yong;Lee, Han-Seung
    • Computers and Concrete
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    • v.14 no.3
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    • pp.247-262
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    • 2014
  • Partial replacement of Portland cement by slag can reduce the energy consumption and $CO_2$ emission therefore is beneficial to circular economy and sustainable development. Compressive strength is the most important engineering property of concrete. This paper presents a numerical procedure to predict the development of compressive strength of slag blended concrete. This numerical procedure starts with a kinetic hydration model for cement-slag blends by considering the production of calcium hydroxide in cement hydration and its consumption in slag reactions. Reaction degrees of cement slag are obtained as accompanied results from the hydration model. Gel-space ratio of hardening slag blended concrete is determined using reaction degrees of cement and slag, mixing proportions of concrete, and volume stoichiometries of cement hydration and slag reaction. Furthermore, the development of compressive strength is evaluated through Powers' gel-space ratio theory considering the contributions of cement hydration and slag reaction. The proposed model is verified through experimental data on concrete with different water-to-binder ratios and slag substitution ratios.

An Experimental Study on the Non-Structural Lean Concrete's Dry Shrinkage with industrial by-product (산업부산물을 활용한 비구조용 콘크리트의 건조수축 특성에 관한 실험적 연구)

  • Hwang, Moo Yeon;Yang, Wan Hee;Park, Dong Cheol;Kim, Woo Jea
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.216-217
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    • 2017
  • Slag cement or ternary blended cement is mainly used for non-structural lean concrete for the purpose of foundation work or protection of the waterproof layer on the roof of buildings. However, such non-structural lean concrete has a lot of drying shrinkage cracks, which makes it difficult to maintain the quality of the structure. Therefore, in this study, the compressive strength and the drying shrinkage of ternary blended cement(blended of portland cement, blast furnace slag, fly ash from combined heat and power Plant) for non-structural lean concrete were examined. As a result, it was confirmed that this non-structural lean concrete reduced drying shrinkage compared to the conventional ternary blended cement using fly ash from power plant.

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The Mechanical Properties of Concrete Using Blended Super Low Heat Cement (혼합형 초저발열 시멘트를 사용한 콘크리트의 물성-현수교 앵커리지 콘크리트 대상-)

  • 송용순;강석화;손명수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.341-344
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    • 1999
  • In the case of the offshore concrete structures like the anchorage block of a suspension bridge of Kwangan Grand Road, there is a need of the concrete which has low heat of hydration and good resistance for sea-water attack. In this study, the blended super low heat cement which satisfies that requirement was developed and several tests were carried out. The concrete using the blended super low heat cement showed lower adiabatic temperature rise than 3$0^{\circ}C$ and good early strength. Also, its passed charge(coulomb) to resist chloride ion penetration was very low.

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A Study on the Resistance to Sea Water and High Flowing Properties of Concrete Using Blended Low Heat Cement (혼합형 저발열 시멘트를 사용한 콘크리트의 초유동성 및 내해수성에 관한 연구)

  • 송용순;노재호;강석화
    • Magazine of the Korea Concrete Institute
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    • v.10 no.6
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    • pp.281-289
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    • 1998
  • This study has been performed to test the flowability and filling ability of high flowing concrete as well as distribution of aggregate and pore of core specimen, heat of hydration, compressive strength and core strength of concrete. In addition, the resistance to chloride ion penetration and chemical solutionof concrete was tested in order to evaluate the resistance to sea water of concrete and its application of high flowing concrete using blended low heat cement in the field of Seohae Grand Bridge. The properties of high flowing concrete with blended low heat cement were compared with ordinary 25-240-15 concrete using Type V cement. As the results of this study, the flowability and filling ability of high flowing concrete with blended low heat cement is satisfied without vibration. Though the cement content of high flowing concrete with blended low heat cement was 400kg/m$^2$, the rising temperature of it was relatively lower than that of the ordinary 25-240-15 concrete with Type V cement. Also, the compressive of high flowing concrete with blended low heat cement is similar to that of the ordinary 25-240-15 concrete with Type V cement.

Microstructural properties of hardened cement paste blended with coal fly ash, sugar mill lime sludge and rice hull ash

  • Opiso, Einstine M.;Sato, Tsutomu;Otake, Tsubasa
    • Advances in concrete construction
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    • v.5 no.3
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    • pp.289-301
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    • 2017
  • The synergistic interactions of supplementary cementitious materials (SCMs) with ordinary portland cement (OPC) in multi-blended systems could enhance the mechanical and durability properties of concrete and increase the amount of cement that can be replaced. In this study, the characteristics of the hydration products as well as paste microstructure of blended cement containing 20% coal fly ash, 10% rice hull ash and 10% sugar mill lime sludge in quaternary blended system was investigated. Portlandite content, hydration products, compressive strength, pore size distribution and microstructural architecture of hydrated blended cement pastes were examined. The quaternary blended cement paste showed lower compressive strength, reduced amount of Portlandite phases, and higher porosity compared to plain hardened cement paste. The interaction of SCMs with OPC influenced the hydration products, resulting to the formation of ettringite and monocarboaluminate phases. The blended cement paste also showed extensive calcium silicate hydrates and calcium aluminate silicate hydrates but unrefined compared to plain cement paste. In overall, the expected synergistic reaction was significantly hindered due to the low quality of supplementary cementitious materials used. Hence, pre-treatments of SCMs must be considered to enhance their reactivity as good quality SCMs can become limited in the future.

A Study on the Durability of Concrete made with Various Cements Containing Additive (시멘트 혼합재 첨가에 따른 콘크리트 내구 특성)

  • 김창범;조계흥;최재웅;김동석;박춘근
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04b
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    • pp.687-692
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    • 1998
  • This paper covers concrete durability made with portland cement type I and V, and granulated blast furnace slag blended cements 40 and 60%. Typical properties of cements and compressive strength development, drying shrinkage, carbonation, freezing and thawing properties of concretes were investigated. In addition, effects of CI penetration on various concretes with/without a freezing and thawing treatment were also studied. Portland cement type I and V were superior to the blended cement in the properties of compressive strength development, drying shrinkage, carbonation and freezing and thawing durability. In the respect of resistant of CI Blended cement showed better than the portland cement due to high permeability. But the blended cement with a freezing and thawing treatment presented a much decreased resistance of CI penetration.

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The Evaluation of Adiabatic Temperature rise in Concrete by Using Blended Cement Hydration Model (혼합시멘트 수화모델을 이용한 콘크리트의 단열온도상승 예측에 관한 연구)

  • Wang, Xiaoyong;Cho, Hyeong-Kyu;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.31-32
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    • 2011
  • Granulated slag from metal industries and fly ash from the combustion of coal are industrial by-products that have been widely used as mineral admixtures in normal and high strength concrete. Due to the reaction between calcium hydroxide and fly ash or slag, the hydration of concrete containing fly ash or slag is much more complex compared with that of Portland cement. In this paper, the production of calcium hydroxide in cement hydration and its consumption in the reaction of mineral admixtures is considered in order to develop a numerical model that simulates the hydration of concrete containing fly ash or slag. The heat evolution rates of fly ash- or slag-blended concrete is determined by the contribution of both cement hydration and the reaction of the mineral admixtures. Furthermore, the temperature distribution and temperature history in hardening blended concrete are evaluated based on the degree of hydration of the cement and the mineral admixtures. The proposed model is verified through experimental data on concrete with different water-to-cement ratios and mineral admixture substitution ratios.

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