• 제목/요약/키워드: cement production

검색결과 390건 처리시간 0.026초

미립자 시멘트를 이용한 조강 콘크리트의 내구성 검토 (Durability of High Early Strength Concrete Using Fine Particles Cement)

  • 김용직;박상준;김경민
    • 콘크리트학회논문집
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    • 제23권6호
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    • pp.757-763
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    • 2011
  • 콘크리트의 효율적인 조기강도 확보를 위해 시멘트의 성능 향상에 주안점을 두고 연구를 진행하였다. 이 연구는 선행 연구인 시멘트 생산 공정 중 부수적으로 발생되는 크기가 작은 시멘트(이하 미립자 시멘트, FC라 함)를 이용하는 콘크리트의 조기강도 발현 특성 연구에 대한 후속 연구로서 내구성 검토를 실시하였다. 실험 결과 굳지 않은 콘크리트에서는 각 배합별 목표 범위를 모두 만족하는 것으로 나타났고, 미립자 시멘트를 혼입하였을 때 응결시간은 촉진되었고 압축강도는 증진되었으며 수화열은 유사한 수준인 것으로 평가되었다. 특히, 내구성 측면에서는 미립자 시멘트 혼입 유 에 따라 모든 실험 항목에서 유사한 수준인 것으로 평가되었다.

High-velocity impact of large caliber tungsten projectiles on ordinary Portland and calcium aluminate cement based HPSFRC and SIFCON slabs -Part I: experimental investigations

  • Korucu, H.;Gulkan, P.
    • Structural Engineering and Mechanics
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    • 제40권5호
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    • pp.595-616
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    • 2011
  • Impact experiments have been carried out on concrete slabs. The first group was traditionally manufactured, densely reinforced concrete targets, and the next were ordinary Portland and calcium aluminate cement based HPSFRC (High performance steel fiber reinforced concrete) and SIFCON (Slurry infiltrated concrete) targets. All specimens were hit by anti-armor tungsten projectiles at a muzzle velocity of over 4 Mach causing destructive perforation. In Part I of this article, production and experimental procedures are described. The first group of specimens were ordinary CEM I 42.5 R cement based targets including only dense reinforcement. In the second and third groups, specimens were produced using CEM I 42.5 R cement and Calcium Aluminate Cement (CAC40) with ordinary reinforcement and steel fibers 2 percent in volume. In the fourth group, SIFCON specimens including 12 percent of steel fibers without reinforcement were tested. A high-speed camera was used to capture impact and residual velocities of the projectile. Sample tests were performed to obtain mechanical properties of the materials. In the companion Part II of this study, numerical investigations and simulations performed will be presented. Few studies exist that examine high-velocity impact effects on CAC40 based HPSFRC targets, so this investigation gives an insight for comparison of their behavior with Portland cement based and SIFCON specimens.

A review on pavement porous concrete using recycled waste materials

  • Toghroli, Ali;Shariati, Mahdi;Sajedi, Fathollah;Ibrahim, Zainah;Koting, Suhana;Mohamad, Edy Tonnizam;Khorami, Majid
    • Smart Structures and Systems
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    • 제22권4호
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    • pp.433-440
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    • 2018
  • Pavements porous concrete is a noble structure design in the urban management development generally enabling water to be permeated within its structure. It has also capable in the same time to cater dynamic loading. During the technology development, the quality and quantity of waste materials have led to a waste disposal crisis. Using recycled materials (secondary) instead of virgin ones (primary) have reduced landfill pressure and extraction demanding. This study has reviewed the waste materials (Recycled crushed glass (RCG), Steel slag, Steel fiber, Tires, Plastics, Recycled asphalt) used in the pavement porous concretes and report their respective mechanical, durability and permeability functions. Waste material usage in the partial cement replacement will cause the concrete production cost to be reduced; also, the concretes' mechanical features have slightly affected to eliminate the disposal waste materials defects and to use cement in Portland cement (PC) production. While the cement has been replaced by different industrial wastes, the compressive strength, flexural strength, split tensile strength and different PC permeability mixes have depended on the waste materials' type applied in PC production.

Strength and durability characteristics of bricks made using coal bottom and coal fly ash

  • Ashish, Deepankar Kumar;Verma, Surender Kumar;Singh, Joginder;Sharma, Namesh
    • Advances in concrete construction
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    • 제6권4호
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    • pp.407-422
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    • 2018
  • The study evaluates properties of brick having coal ash and explores the possibility of utilization of coal bottom ash and coal fly ash as an alternative raw material in the production of coal ash bricks. Lower cement content was used in the investigations to attain appropriate strength and prohibit high carbon content that is cause of environmental pollution. The samples use up to 7% of cement whereas sand was replaced with bottom ash. Bricks were tested for compressive strength, modulus of rupture, ultrasonic pulse velocity (UPV), water absorption and durability. The results showed mix proportions of bottom ash, fly ash and cement as 1:1:0.15 i.e., M-15 achieved optimum values. The coal ash bricks were well bonded with mortar and could be feasible alternative to conventional bricks thus can contribute towards sustainable development.

플라이애시 및 실리카흄을 사용한 고강도유동화콘크리트의 공학적 특성에 관한 실험적 연구 (제1보, 아직 굳지않은 콘크리트의 시공성 검토) (An Experimental Study on the Engineering Properties of High Strength Flowing Concrete Using Flyash and Silicafume (Part I. Workability of Fresh Concrete))

  • 김진만;이상수;김규용;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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    • pp.161-166
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    • 1994
  • Production of high strength concrete requires a low water-cement ratio and this leads to the high cement content. Mineral admixture like fly ash(FA) is often cheaper than ordinary portland cement(OPC) and this factor in combination with possible improvement in workability and moderation of the heat evolution of the cement-rich mixes tends to encourage its use. The other mineral admixture that its use has been widly advocated is silica fume that increases compressive strength due to its pozzolanic reaction. The objective of this study is to assess the contribution of mineral admixtures(FA, SF) to the workability and the strength of concrete with low water-binder ratios. In this experimental study that investigates and analyzes the properties of fresh concrete, it is presented that using admixtures like flysh and silica fume as binding material increases properties of high strength flowing concrete having very low water cementitious ratios of 0.25 and 0.30.

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플라이애시 및 실리카흄을 사용한 고강도유동화 콘크리트의 공학적 특성에 관한 실 험적 연구 (제 2보. 경화콘크리트의 공학적 특성 검토) (An Experimental Study on the Engineering Properties of High Strength Flowing Concrete Using Flyash and Silicafume (Part 2. Engineering Properties of Hardened concrete))

  • 김진만;이상수;김규용;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.84-87
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    • 1995
  • Production of high strength concrete requires a low water-cement ratio and this leads to the high cement content. Mineral admixture like fly ash(FA) is often cheaper than ordinary portland cement(OPC) and this factor in combination with possible improvement in workability and moderation of the heat evolution of the cement-rich mixes tends to encourage its use. The other mineral admisture that its use has been widly advocated is silica fume that increases compressive strength due to its pozzolanic reaction. The objective of this study is to assess the contribution of mineral admixtures(FA, SF) to the workability and the strength of concrete with low water-binder ratios. In this experimental study that investigates and analyzes the properties of fresh concrete. it is presented that using admixtures like flyash and silica fume as binding material increases properties of high strength flowing concrete having very low water cementitious ratios of 0.25 and 0.30.

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골재의 입도 및 입형이 제품용 시멘트 모르타르의 강도 및 흡수율에 미치는 영향 (Influences of Grading and Grade Shape in Aggregates on the Strength and Absorption of Cement Mortar Products)

  • 한천구;신병철;김기철;이상태
    • 콘크리트학회논문집
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    • 제12권1호
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    • pp.45-52
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    • 2000
  • The quality of cement mortar products largely depends on various work conditions, specially on the grading and grade shape of aggregates. However, the effect of grading and grade shape on the quality is not considered by both KS codes and production processes, resulting in the increase of the possibility of quality degradation. The objective of this study was to investigate the effect of grading and grade shape on the strength and absorption characteristics of cement mortar products. Flexural and compressive strength increased with the increase of fineness modulus and W/C. The strength increase was measured larger with river sand than with crushed sand. Absorption tended to decrease with the increase of fineness modulus and W/C, but did not affected by the source of sand.

Lightweight aggregates coated with colemanite

  • Bideci, Alper;Bideci, Ozlem Salli;Oymael, Sabit;Gultekin, Ali Haydar;Yildirim, Hasan
    • Computers and Concrete
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    • 제19권5호
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    • pp.451-455
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    • 2017
  • Technological advancements in the field of building materials are achieved day by day. In this study, a new lightweight concrete aggregate is produced by mixing certain rates of colemanite (0%, 7.5%, 12.5%, 17.5%), cement and coating the surface of pumice aggregate with this mixture. Thin aggregate sections are analyzed with specific gravity, unit weight, water absorption, impact, and crushing experiments. In this way, the production of cement and cement+colemanite coated lightweight concrete aggregates is investigated and an opinion on the likely behavior of these concrete types is provided.

Development of Soil-cement in Earth-block Materials

  • Wiwattanachang, N;Maneein, N;Parwong, T;Nummeesri, K
    • International Journal of Advanced Culture Technology
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    • 제3권1호
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    • pp.78-85
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    • 2015
  • In Thailand, the electricity consumption is very high with the intention of reduce high temperature in the building. Since 2000, a lot of people paying attention to Green-Building concept. A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally. Therefore, the Earth-Block (EAB) product is appropriated approach to reduce energy consumption in the buildings. The EAB is produced with environmentally friendly process, which does not release harmful pollution and effective cost. The main significant character is durable materials for building construction. This study aims to develop the new thermal insulation by using soil-cement with vetiver grass fibre. Additionally, it describes the innovative systems used in production of EAB materials by mixing the soil-cement with vetiver grass fibre. This paper reveals lowest costs, space configurations changing and greater design flexibility for constructing the building.

3성분계 무기결합재 패널크기에 따른 건조수축 특성 (Dry Shrinkage Characteristic according to the Ternary System Inorganic Binder Panel Size)

  • 이진우;이상수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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    • pp.144-145
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    • 2014
  • In the cement,that is the main materials of the panel, as to the cofired process, more than 1,300 enormous energies is consumed, in addition the greenhouse gas generated in the process of producing the cement occupies 6.3% of the country whole emission quantity. And the carbon dioxide of about 0.8 ton is the cement ejected in 1 production. Accordingly, the panel utilizing the industrial byproduct is developed. Accordingly, this research is the experiment which makes the individual size into the environment-friendly inorganic binder panel and by using the blast furnace slag, which is the industrial byproduct with the cement substitute material red mud, silica fume, and etc. looks at the dry shrinkage. The length variation in which the panel which is 450 with the dry shrinkage result of measurement, thickness 12mm, and size 450mm is the smallest was shown.

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