• Title/Summary/Keyword: Cement Replacement

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Rheological Properties of Ordinary Portland Cement - Blast Furnace Slag - Fly Ash Blends Containing Ground Fly Ash (분쇄된 플라이애시를 혼합한 3성분계 시멘트의 유동특성)

  • Park, Hyo-Sang;Yoo, Dong-Woo;Byun, Seung-Ho;Song, Jong-Taek
    • Journal of the Korean Ceramic Society
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    • v.46 no.1
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    • pp.58-68
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    • 2009
  • In this study, rheological properties of ternary system cement containing ground fly ash(F3, Blaine specific surface area $8,100\;cm^2/g$) were investigated using mini slump, coaxial cylinder viscometer and conduction calorimeter. In the results, the segregation resistance was observed at high W/B and PC area while the replacement ratio of F3 was increasing. The 2:5:3 system was shown in higher fluidity and lower hydration heat than 3:4:3 system. The segregation range of cement pastes occurred over 175 mm in average diameter by mini slump and below $10\;dynesec/cm^2$ of the plastic viscosity or below 50 cP of the yield stress by coaxial cylinder viscometer. It was observed that even if BFS and FA blended together admixture properties would remaine as they were separately. The properties of admixture would not be changed. On the above results, the decreased replacement ratio of OPC and increased replacement ratio of admixtures would be possible.

Properties of Blast Furnace Slag Cement Modified with Electric Arc Furnace Slag (전기로 슬래그를 치환한 고로 슬래그 시멘트의 특성)

  • Lee, Seung-Heun;Hwang, Hae-Jeong;Kwon, Sung-Ku
    • Journal of the Korean Ceramic Society
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    • v.43 no.7 s.290
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    • pp.408-414
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    • 2006
  • Properties of slag cement that contained 50 wt% of blast furnace slag were studied when replaced blast furnace slag powder with electric arc furnace slag powder. Electric arc furnace slag was aged for about 2 months in the air by being crushed to be 1-3 mm in size. As a result of the experiment, it was proven that the water content for obtaining the same consistency became decreased as slag is replaced with electric arc furnace slag instead of blast furnace slag. Also, the workability of mortar increased about 30% at the same ratio of water to binder when blast furnace slag was completely replaced with electric arc furnace slag. The compressive strength of mortar on the 28 days increased when a slag replacement rate became 10 wt%, however, it rather decreased when the slag replacement rate exceeded 10 wt%. The heat of hydration became higher for the first 14 h in case of the replacement of slag cement by electric arc furnace slag. Yet, it decreased when 14 h had passed. Therefore, when all blast furnace slag was replaced with electric arc furnace slag, about 15 cal/g heat of hydration decreased when it passed about 72 h.

Enhancement in the quality of mortar which uses uses 3-type blast-furnace slag cement and circulated fine aggregate, according to replacement ratio changes of waste refractories and desulfurized plaster (폐내화물 및 탈황석고의 치환율 변화에 따른 3종 고로슬래그 시멘트와 순환잔골재를 사용하는 모르타르의 품질향상)

  • Lee, Jae-Jin;Lee, Jea-Hyeon;Baek, Cheol;Kim, Min-Sang;Yoon, Won-Geun;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.56-57
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    • 2016
  • Recently amongst Korea's construction companies there has been heightened interest in environment load reduction and resource recycling. As a result, the construction industry is examining recycled materials alternative to cement and blast-furnace slag (BS henceforth) cement, such as waste refractories and desulfurized plaster. This study analyzes the liquidity and intensity characteristics of mortar according to changes in replacement ratios of waste refractories and desulfurized plaster, used as industry by-products in mortar environments that use BS 3-type cements and circulated fine aggregate. As a result, the greater the increase in replacement ratios of desulfurized plaster, the greater the increase in liquidity and air quantity, as well as compression strength.

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Effect of the Replacement of Fine Particle Cement on Mechanical Properties of the Concrete (미분 시멘트의 치환율 변화가 콘크리트의 역학적 특성에 미치는 영향)

  • Choi, Sung-Yong;No, Dong-Hyun;Kim, Kyung-Min;Park, Sang-Joon;Kwan, O-Bong;Han, Min-Cheol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.11a
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    • pp.133-136
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    • 2007
  • This study investigates mechanical properties of the concrete using fine particle cement which is manufactured by the pulverizing process. The variable factors are 3 types of W/C such as 40, 50, and 60%, 3 types of curing temperature such as 5, 20, and $35^{\circ}C$, and 5types of the replacement of the fine particle cement such as 0, 25, 50, 75, and 100%. The unit water content, S/a and amount of the SP and AE agents to secure the slump and air content is gradually increased in accordance with amount of replacement. It can be confirmed that the delay of the setting time depending on FC content is decreased corresponding to FC content, so the effect of the acceleration to the setting time is expected. The compressive strength corresponding to FC content is proportionally increased, and the growth is confirmed about $30{\sim}40%$ at a day in 50% of FC contents. However, the increase of the strength is gradually decreased in accordance with increasing age.

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Behaviors of Soil-cement Piles in Soft Ground (연약지반에 설치된 소일시멘트말뚝의 거동)

  • Kim, Young-Uk;Kim, Byoung-Il;Xiaohong Bai
    • Journal of the Korean Geotechnical Society
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    • v.19 no.3
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    • pp.45-51
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    • 2003
  • This study was undertaken to investigate behavior characteristics of soil-cement piles in composite foundations through computer analysis. The soil-cement piles with cushion subjected to the vertical central loading only were analyzed using the program - “ABAQUS”. The investigation was conducted for various conditions including soil property, pile dimension, replacement ratio, pile/soil modular ratio, and load intensity. The results of analysis provided not only the load transfer and settlement behaviors but also the effective pile length and load distribution between a pile and soil. It was concluded that in the design of composite foundations, the modular ratio and replacement ratio are two design parameters.

An Analysis on Concrete Properties with the Fineness of Waste Limestone (폐석회석의 분말도 변화에 따른 콘크리트의 특성분석)

  • Ryu, Hyun-Gi;Woo, Jong-Kwon
    • Journal of the Korea Institute of Building Construction
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    • v.7 no.1 s.23
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    • pp.85-90
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    • 2007
  • According as industry develops rapidly, problem of resources exhaustion and environmental pollution is appearing. Way to use construction waste that is development of new compound material and Industry product is required. Limestone powder that is Industry product is $CaCO_3$. and vicosity is promotion effect because there is no damage to hydration of cement and powder is very thin and water tightness increases. This research purposed to analyze concrete property changing limestone fineness. According as the limestone powdered replacement ratio increases, slump and unit capacity mass increased, and the air content decreased according as the replacement ratio increases. Compressive strength and tensile strength decreased according as the limestone powder replacement ratio increases.

Fundamental Properties of Zero-Cement Mortar with Variation Replacement Ratio of Incineration Waste Ash and Gypsum (무수석고와 소각장애시의 치환율 변화에 따른 고로슬래그 미분말 활용 무 시멘트 모르타르의 기초적특성)

  • Lu, Liang Liang;Kim, Jun Ho;Baek, Byung Hoon;Han, Cheon Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.242-243
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    • 2014
  • In this study, industrial by-products including blast furnace slag, incineration ash and waste gypsum were used with recycled fine aggregates to manufacture the zero-cement mortar. The replacement ratio of anhydrite gypsum was fixed as 0, 10%, 20% the replacement ratio fo WA1 was fixed as 0.5% and 1.0%, respectively. It could be identified that when the replacement of gypsum was 20% and WA1 of 1.0%, the strength could be in the range of normal strength.

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Engineering Properties of Zero-Cement Mortar with Variation Replacement Ratio of Incineration Waste Ash and Gypsum (석고종류 및 소각장애시 치환율 변화에 따른 고로슬래그 미분말 활용 무시멘트 모르타르의 공학적 특성)

  • Park, Jun Hui;Huang, Jin Guang;Kim, Jun Ho;Jo, Man Ki;Han, Min cheol;Han, Cheon Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.222-223
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    • 2014
  • In this study, industrial by-products including blast furnace slag, incineration ash and waste gypsum were used with recycled fine aggregates to manufacture the zero-cement mortar.The replacement ratio of dihydrate gypsum and anhydrite gypsum was fixed as 0 and 10%, the replacement ratio fo WA1 was fixed as 0.5% and 1.0%, respectively. It could be identified that when the replacement of gypsum was 10% and WA1 of 1.0%, the strength could be in the range of normal strength.

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Properties of Polymer Modified Mortars Substitution Re-dispersible Polymer Powders (재유화형 폴리머를 첨가한 폴리머시멘트 모르타르의 특성)

  • Jang, Kun-Young;Ryu, Dong-Woo;Jeon, Chan-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.19-20
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    • 2018
  • For this study, a test was conducted on the basic polymer property depending on the replacement amount of polymer. The result showed that the flow of slump was increased with the increase of polymer replacement amount and an amount of air entraining. In addition, with a decrease of unit W/B, an amount of bleeding was reduced, and the first and final time for 6% replacement amount was found to be the fastest. This implies that replacement of more than 6% may affect the hydration of cement.

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An Experimental Study on the Physical Properties of Ternary Concrete according to Replacement Ratio of Pozzolanic Admixtures (포졸란재 혼입율에 따른 3성분계 콘크리트의 물리적 특성에 관한 실험적 연구)

  • Kwon, Hae-Won;Lee, Jin-Woo;Bae, Yeoun-Ki;Lee, Jae-Sam
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.773-776
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    • 2006
  • This experimental study is the fundamental report to use the ternary concrete. This study performed to know physical properties of ternary concrete according to replacement ratio of pozzolanic admixtures and curing temperature conjugation. To investigate Strength development properties of according to replacement ratio of pozzolanic admixtures, both fly ash replaced on portland cement in 5, 10 and 15% weight ratios and blast furnace slag replaced on the portland cement in 5, 15, 20, 30 and 40% weigt ratios was used. Also this is studied fresh and hardened concrete properties in condition of curing temperature $10^{\circ}C\;and\;20^{\circ}C$. The followings are the summary of which concluded in this study. Considering the concrete cured over 28 days compressive strength, most replacement ratios of pozzolanic admixtures were higher than plain concrete that. Compressive strength development properties of ternary concrete according to curing temperature conjugation were similar except for early age.

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