• 방사성폐기물학회지
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• 제18권4호
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• pp.465-479
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• 2020

Two waste forms, namely cement and geopolymer, were investigated and tested in this study to solidify the corrosive sludge generated from the surface and precipitates of the tubes of steam generators in nuclear power plants. The compressive strength of the cement waste form cured for 28 days was inversely proportional to waste loading (24.4 MPa for 0wt% to 2.7 MPa for 60wt%). The corrosive sludge absorbed the free water in the hydration reaction to decrease the cementation reaction. When the corrosive sludge waste loading increased to 60wt%, the cement waste form showed decreased compressive strength (2.7 MPa), which did not satisfy the acceptance criteria of the repository (3.45 MPa). Meanwhile, the compressive strength of the geopolymer waste form cured for 7 days was proportional to waste loading (23.6 MPa for 0wt% to 31.9 MPa for 40wt%). The corrosive sludge absorbed the free water in the geopolymer when the water content decreased, such that a compact geopolymer structure could be obtained. Consequently, the geopolymer waste forms generally showed higher compressive strengths than cement waste forms.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.217-222
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• 1994

Generally speaking, grouting on the base stabilizes the ground as the aspects of mechanic and engineering properties, with drilling hole at any depth of the earth, and pressuring the cement milk or special chemical grouting material in it. The purpose of grouting on the base is waterproofness and solidification of the ground by earth concreting that the cement milk pass through paticles of soil or crack of rock. This report shows the fundamental properties of microcement compared with those of ordinary portland cement in a point of grouting. It also describes that experimental applications on the treatment of the weathered rock at the constructior of Taegu subway and Boryong earth filled dam site, south of chungchung province, resulted in success.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.321-322
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• 2009

산화마그네숨을 주성분으로 하고 있어 시멘트 고화로 문제가 되는 육가 크롬을 포함하지 않을 뿐만 아니라 시멘트, 석회류와 마찬가지로 내구성이 있는 경화물이 생성되기 때문에 불용화 처리 효과의 장기 안정성이 우수하며 인산염 시멘트의 압축강도는 $21^\sim$28MPa로서 포틀랜드 시멘트와 비교할만하다. 본 연구에서는 이러한 인산염 마그네시아의 특성을 이용하여 중금속인 Cr과 Pb의 고용화 적용 가능성을 실험하였으며, 중금속 이온과 마그네시아 시멘트에 의한 고용체의 생성 및 고정화 된 고용체에 서의 중금속 이온의 용출특성을 검토 하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.453-458
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• 2001

This study was performed to reuse the dyeing wastewater sludge treated by Fenton process through the solidification/stabilization technique. To solidify the dyeing sludge the industrial by-products such as blast furnace slag, fly ash and waste sand with cement were used. The laboratory scale and pilot scale test were conducted at room temperature to make construction brick which has high compressive strength and low leaching of heavy metals. The experimental results showed that blast furnace slag and fly ash could be used instead of cement and the products satisfied the regulation of Korean Standards. The blast furnace slag increased the compressive strength and the optimum ratio of slag/dyeing sludge on dry basis was found 0.4. The solidifying agent of SB series could increase rapidly the compressive strength and the optimum ratio of solidifying agent/sludge on dry basis was 0.26 at which the strength was two times compared with non-added condition. The portion of waste and industrial by-products in matrix was over 80%. From the pilot test the optimum pressure in molding was 100kg/$\textrm{cm}^2$ at which the compressive strength was over 100kg/$\textrm{cm}^2$. And the strength increased continuously to 160kg/$\textrm{cm}^2$ until 120 days curing time due to pozzolanic reaction. When SB-20 as a solidifying agent was used, the unconfined compressive strength of dyeing sludge could be obtained 110kg/$\textrm{cm}^2$ which satisfied the regulation of cement brick in Korea Standard(KS).

• 환경위생공학
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• 제17권3호
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• pp.21-30
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• 2002

This study was Performed to evaluate the effective solidification of Cd sludge using cement and power plant fly ash as cement admixture, to identify the leaching characteristics of the heavy metal Cd sludge solidified, and to develope proper KLT(Korean Leaching Test) of hazardous waste. KLT was compared with EPT(Extraction Procedure Toxicity) and TCLP(Toxicity Characteristics Leaching Procedure). Fly ash contents ranged from 0% to 30% of cement weight. The experimental results showed that the optimum amount of fly ash replaced was 10% to 15% and KLT was less appropriate than EPA and TCLP. Also the purpose of the study was to suggest the modification factors on the leaching test currently used, based on the above mentioned aspects. The effects of pH, leaching time, leaching for agitating intensity, and leaching solvent were investigated. As the result of test, the leaching potential was relatively high when the pH and agitation intensity of leaching solution were 5 and 150rpm, respectively. Leaching time of six hours was found to be sufficient and the use of acetic acid as a leaching solvent is more useful in landfill site particularly.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.906-909
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• 2005

The purpose of this paper is to study on the construction of roadbed with environmental friendly soil amendment agent and reinforced fiber. The special amendment agent and fiber used in this study has a function of soil-cement-agent solidification and reinforcement. A series of laboratory experiments including unconfined compressive strength, tensile strength, compaction test were carried out to investigate the physical and mechanical characteristics of roadbed treated by solidifying agent and fiber. The results of this research showed that the roadbed using poor soil could be efficiently constructed by treatment of this amendment agent and fiber.

• Environmental Engineering Research
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• 제11권1호
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• pp.54-61
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• 2006

An electron probe microanalysis (EPMA) investigation can provide quantitative and qualitative insight into the nature of the surface and bulk chemistry on solidified waste forms(SWF). The proportion of Pb in grain areas is below 0.3 wt. %, and the proportion near the border of the grain slightly increases to 0.98 wt. % but in the inter-particle areas farther from the grain, the concentration of Pb markedly increases. It is apparent that very little Pb diffuses into the tricalcium silicate($C_3S$) particles and most of the Pb exists as precipitates of sulfate, hydroxide, and carbonate in the cavity areas between $C_3S$ grains. Calcite additions on Pb-doped SWF are also observed to induce deeper incorporation of lead into the cement grains with EPMA line-analysis of cross-sections of cement grains. The line-analysis reveals the presence of $0.2{\sim}5$ weight % Pb over $5\;{\mu}m$ from cement grain boundaries. In the inter-particle areas, the ratio of Ca, Si, Al and S to Pb is relatively similar even at some distance from the grain border and the Pb (wt. %) ratio is reasonably constant throughout the whole inter-particles area. It is apparent that the enhanced development of C-S-H on addition of calcite can increasingly absorbs lead species within the silica matrix.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.537-540
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• 2004

Recently, for industrial development period, concrete structures in domestics have been increased. They were deteriorated by attack of carbonation, freeze-thaw and corrosion etc. In hence they were demolished and reconstructed, resulted in waste concrete particles. In this paper, waste concrete particles (WCP) by product from different crushing and selecting process were used in soil cement-based pavement in the various recycling. For using WCP in soil cement-based pavement, the Qualities, physical and chemical properties, of WCP should be researched. In the first step, the specified compressive strength of mortar for two types of clay sand soil and clay soil respectively was experimented to be 15 Mpa and then optimum mixing ratio of chemical solidification agent were decided in the range of $1.5\~3.0\%$ in the replacement with cement weight content. In the second step, based on the prior experimental results, recycling possibility of WCP in soil cement-based pavement was studied. In the result of experiment the mixing ratio of WCP were 5, 10, 15 and $20\%$ in the replacement with soil weight and the compressive strength of mortar was somewhat decreased according to the increase of the mixing ratio of WCP.

• 한국환경과학회지
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• 제26권11호
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• pp.1267-1274
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• 2017

A Controlled Low-Strength Materials (CLSM) is suitable for mine backfilling because it does not require compaction owing to it high fluidity and can be installed quickly. Therefore, a CLSM utilizing $CO_2$-solidified Circulating Fluidzed Bed Combustion (CFBC) coal ash was developed and it's properties were investigated, since. $CO_2$-solidification of CFBC coal ash can inhibit exudation of heavy metals. The chemical composition and specific surface area of Pulverized coal Combustion fly ash and CFBC fly ash were analyzed. The water ratio, compressive strength and length change ratio of CLSM were confirmed. The water ratios differed with the specific surface area of the CLSM. It was confirmed that the porosity of CLSM affected its compressive strength and length change ratio.

• 한국구조물진단유지관리공학회 논문집
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• 제8권4호
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• pp.87-96
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• 2004

소일시멘트는 자연 상태의 흙을 주원료로 시멘트, 혼합수를 배합하여 일반포장용 콘크리트에 준하는 강도를 발휘하는 특수콘크리트로서 최근 도로포장뿐만 아니라 연악지반 개량 동 여러 분야에 활용되고 있다. 본 연구에서는 화강토 및 붕적토에 고화제를 첨가하여 일축압축강도의 특성 및 시간의존 거동을 규명하고자 하였다 연구 결과 일축압축강도는 시멘트 함량의 증가와 양생기간의 증가에 따라 뚜렷한 강도 증가를 타나내었으며 미 세립분이 많을 수 록 강도가 감소하였으며 X-선 회절 분석 결과 소일시멘트에서 반응생성물인 Vermiculite가 발견되었다 동적반복재하크리프 시험 결과 히스테리시스 곡선으로부터 재료의 동적특성인 복합전단컴플라이언스, 복합전단계수, 위상각을 구하였으며 재료의 동적특성으로부터 크리프 거동의 예측이 가능 하였다