• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.232-235
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• 2004

This study aims to manufacture non-sintering cement(NSC) by adding phosphogypsum(PG) and waste lime(WL) to granulated blast furnace slag(GBFS) as sulfate and alkali activators. This study also investigates the basic physical properties and hydration reaction of NSC, and evaluates its reusing possibility as construction material. Results obtained from this study have shown that GBFS was affected by $So_4^{2-}$ in waste PG and stimuli under wet condition, left slag components, created Ettringite and CSH gels, and eventually started being hydrated. These hydrated creations formed dense structures like CSH based on Ettringite and contributed in allowing the mortar to reveal high strength.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.607-610
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• 2005

If cement can be manufactured with industrial byproducts such as granulated blast furnace slag(GBFS), phosphogypsum(PG), and waste lime(WL) instead of clinker as its counterproposal, there would be many advantages, including maximum use of these industrial byproducts for high value-added resources, conservation of natural resources and energy by omitting the use of clinker, minimized environmental pollution problems caused by $CO_2$ discharge, and reduction of the production cost. This research investigates the chemical resistance of NSC mortar added PG and WL to GBFS as sulfate and alkali activators. The result of experiment of chemical resistance, showed that NSC is very excellent in acid resistance and seawater resistanc. Such a reasons are that the hydrate like CSH gel and ettringite formed dense pore structure of NSC matrix.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.453-456
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• 2006

If cement can be manufactured with industrial byproducts such as granulated blast furnace slag(GBFS), phosphogypsum(PG), and waste lime(WL) instead of clinker as its counterproposal, there would be many advantages, including maximum use of these industrial byproducts for high value-added resources, conservation of natural resources and energy by omitting the use of clinker, minimized environmental pollution problems caused by CO2 discharge, and reduction of the production cost. This research investigates the chloride ion permeability of NSC concrete added PG and WL to GBFS as sulfate and alkali activators. The result of experiment of chloride ion permeability, showed that NSC is very excellent in seawater resistance. Such a reasons are that the hydrate like CSH gel and ettringite formed dense pore structure of NSC matrix.

• Geomechanics and Engineering
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• 제10권2호
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• pp.247-256
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• 2016

In this paper, based on understanding the design theories on soil stabilization, a series of soil stabilizers were prepared with different kinds of industrial wastes such as calcined coal gangue (CCG), blast furnace slag (SS), steel slag (SL), carbide slag (CS), waste alkali liquor (JY), and phosphogypsum (PG). The results indicated that when the Portland cement (PC) proportion was lower than 20% in the stabilizer, for the soil sample selected from Wuhan (WT) and Beijing (BT), the unconfined compress strength (UCS) of the stabilized soil specimens could increase 4.8 times and 5.4 times respectively than that of the specimens stabilized only by PC; compared with the UCS of the specimen stabilized only by PC, the UCS of the specimen which was made from soil sample WT and stabilized by the stabilizer composed only by CCG, CS, and PG increased 1.5 times, and UCS of the specimen which was made from soil sample BT and stabilized by the stabilizer composed only by SS, JY, and PG increased 4.5 times.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.101-104
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• 2005

The world's cement demand is anticipated to increase about 2.558$\%$ every year until the first half of the 21st century. To be closed the increase of cenment damand and simultaneously comply with the Kyoto Protocal, cement that gives less carbon dioxide(Co2) discharge should be urgently developed. If cement can be manufactured with industrial byproducts such as granulated blast furnace slag(GBFS), phosphogypsum(PG), and waste lime(WL) instead of clinker as its counterproposal, there would be many advantages including maximum use of these industrial byproducts for high value-added resources, conservation of natural resources and energy by omitting the use of clinker, minimized environmental pollution problems caused by Co2 discharge and reduction of the cost. So this study aims to solve the problems by manufacturing non-sintered cement.

• 한국건축시공학회지
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• 제18권3호
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• pp.305-312
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• 2018

This study is about the development of a non-sintered binder (NSB) which does not require a sintering process by using the industrial by-products Phosphogypsum (PG), Waste Lime (WL) and Granulated Blast Furnace Slag (GBFS). In this report, through SEM analysis of the NSB paste hardening body, micropore analysis of paste using the mercury press-in method and microstructure observation were executed to consider the influence of the formation of the pore structure and the distribution of pore volume on strength, and the following conclusions were reached. 1) Pore structure of NSB paste of early age is influenced by hydrate generation amount by GBFS and activator. 2) Through observing the internal microstructure of NSB binder paste, it was found that the strength expression at early age due to hydration reaction was achieved with a large amount of ettringite serving as the frame with C-S-H gel generated at the same time. It was confirmed that C-S-H gel wrapped around ettringite, and as time passed, the amount generated continually increased, and C-S-H gel tightly filled the pores of hardened paste, forming a dense network-type web structure. 3) For NSB-type cement, the degree of formation of gel pores below $10{\mu}m$ had a greater influence on strength improvement than simple pore reduction by charging capillary pores, and the pore size that had the greatest effect on strength was micropores with diameter below $10{\mu}m$.

• 한국환경복원기술학회지
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• 제7권3호
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• pp.56-63
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• 2004

This study was carried out to find out the effect of by-product gypsum(phosphogypsum, PG) application on enhancement of turf quality. For the first experiment, 10 ton $ha^{-1}$ PG was applied to 1m${\times}$10m (width${\times}$length) Plots with 4 replicates on a sloping area of fairway where turf(Zoysia japonica L.) was grown. Both top- and sub-soil samples were collected before and after treatment and were analyzed for pH, EC(e1ectrica1 conductivity), Ca and Mg contents. At the same time when soil samples were collected, specific color difference sensor value(SCDSV) that represented chlorophyll contents, fresh and dry weight of the turf were determined to find out the effect of PG treatment on turf growth. SCDSV of turf from PG treated plots measured at 98 and 147 days after treatment were significantly higher than those from control. Considering higher fresh and dry weight of leaf per unit area from PG treated plots than that from control, it was concluded that the elevated Ca and S level of the PG treated plots resulted in vigorous leaf growth of turf. For the second experiment 2, 5 and 10 ton $ha^{-1}$ PG were applied to 1m${\times}$10m(width${\times}$length) Plots with 3 replicates at a closer location as was used for the first experiment to find out the appropriate PG application rate. Before and after treatment soil and plant samples were collected and were analyzed by the same way as the first experiment. The pH of all the soil samples collected from PG treated plots at 38 days after treatment was lower than that from control. This trend changed as time passed. However, the pH of the soil from 10 ton $ha^{-1}$ PG treated plot was lower than that from control during the whole period of the second experiment. SCDSV, fresh and dry weight of leaf from PG treated plots at all 3 rates were higher than those from control for the second experiment. PG application to turf will be beneficial for both mass consumption of by-product gypsum and enhancement of turf quality.

• 콘크리트학회논문집
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• 제18권2호
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• pp.267-274
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• 2006

시멘트 산업은 석회석, 점토, 석탄 및 전기를 다량 소모할 뿐만 아니라 지구 온난화 및 산성비의 주요 원인인 $CO_2,\;SO_3$, and NOX 등의 온실가스를 다량 배출하는 산업이기 때문에 향후 온실가스 감축은 시멘트 업계의 가장 큰 현안으로 등장할 것으로 예견된다. 교토의정서의 준수와 시멘트 수요의 증가를 동시에 충족시키기 위해서는 이산화탄소의 배출이 적거나 거의 없는 시멘트의 개발이 필요하다. 본 연구는 고로슬래그미분말에 폐인산석고 및 폐석회를 황산염 및 알칼리 자극제로 이용하여 비소성 시멘트를 제조하고 X선 회절분석, 전자현미경 분석, 열분석 및 pH분석을 통해 비소성 시멘트의 수화반응을 조사하였다. 실험 결과 비소성 시멘트의 주요 생성광물은 고로슬래그 미분말의 유리질 피막이 파괴되면서 알칼리 자극 및 황산염 자극을 받아 고로슬래그 내부에서 용출되는 이온이 인산석고와 반응하여 ettingite를 생성시키고 고로슬래그 중의 남은 성분은 서서히 C-S-H(I)계의 겔상 수화물을 형성함으로서 강도를 발현하며 이때 인산석고는 단순 자극작용 뿐만 아니라 GBFS와 반응하는 결합재 역할도 동시에 수행한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.329-332
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• 2004

This study aims to manufacture non-sintering cement(NSC) by adding phosphogypsum(PG) and waste lime(WL) to granulated blast furnace slag(GBFS) as sulfate and alkali activators. This study also investigates the pore structure of NSC Matrix. The result of experiment of pore structure properties, showed no considerable difference for total pore volume by cement mixing ratio but shows a large distinction in distribution of pore diameter. On the whole, pore-diameter of paste of NSC show that occupation ratio of pore diameter below 10mm is larger and is smaller than OPC and BFSC at pore diameter of over 10nm. Such a reason is that the hydrate like CSH gel and ettringite formed dense pore structure of NSC matrix.