• Advances in concrete construction
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• 제9권3호
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• pp.279-287
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• 2020

This paper focuses on the engineering properties of Bentonite-Cement-Sodium silicate (BCS) grout, which was prepared by partially replacing the ordinary Portland cement in Cement-Sodium silicate grout with lithium bentonite (Li-bent) and sodium bentonite (Na-bent), respectively. The effect of different Water-to-Solid ratio (W/S) and various replacement percentages of bentonite on the apparent viscosity, bleeding, setting time, and early compressive strength of BCS grout were investigated. The XRD method was used to detect its hydration products. The results showed that both bentonites played a positive role in the stability of BCS grout, increased its apparent viscosity. Na-bent prolonged the setting time of BCS, while 5% of Li-bent shortened the setting time of BCS. The XRD analysis indicated that the hydration products between the mixture containing Na-bent and Li-bent did not differ much. Using bentonite as supplementary cementitious material (SCM) to replace partial cement is a promising way to cut down on carbon dioxide emissions and to produce low-cost, eco-friendly, non-toxic, and water-resistant grout. In addition, Li-bent was superior to Na-bent in improving the strength and the thickening of BCS grouts.

• Geomechanics and Engineering
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• 제10권1호
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• pp.77-94
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• 2016

Cyclic triaxial and resonant column tests were conducted to understand the beneficial effects of various grouted sands on liquefaction resistance and dynamic properties. The test procedures were performed on a variety of grouted sands, such as silicate-grouted sand, silicate-cement grouted sand and cement-grouted sand. For each type of grout, sand specimen was mixed with a 3.5% and 5% grout by volume. The specimens were tested at a curing age of 3, 7, 28 and 91 days, and the results of the cyclic stress ratio, the maximum shear modulus and the damping ratio were obtained during the testing program. The influence of important parameters, including the type of grout, grout content, shear strain, confining pressure, and curing age, were investigated. Results indicated that sodium silicate grout does not improve the liquefaction resistance and shear modulus; however, silicate-cement and cement grout remarkably increased the liquefaction resistance and shear modulus. Shear modulus decreased and damping ratio increased with an increase in the amplitude of shear strain. The effect of confining pressure on clean sand and sodium silicate grouted sand was found to be insignificant. Furthermore, a nonlinear regression analysis was used to prove the agreement of the shear modulus-shear strain relation presented by the hyperbolic law for different grouted sands, and the coefficients of determination, $R^2$, were nearly greater than 0.984.

• 한국지반환경공학회 논문집
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• 제7권4호
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• pp.25-34
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• 2006

차수 및 지반보강용 주입재의 주류를 이루고 있는 보통포틀랜드시멘트와 규산나트륨(3호)는 겔화 반응 후에 규산나트륨(3호)에 포함 되어있는 산화나트륨이 시멘트수화 경화물과 반응하지 않은 미반응 규산과 함께 수중에 용탈되며, 내구성이 결여되는 주입재로 인식되고 있다. 본 연구에서는 시멘트 수화 지연제가 규산나트륨-시멘트 겔의 일축압축강도에 미치는 영향을 파악하기 위하여 전자현미경촬영, X-선회절분석, 핵자기공명스펙트럼, 일축압축강도시험 등을 실시하였다. 시멘트 수화지연제인 소디움트리포리포스페이트가 포함된 규산나트륨(3호)-시멘트 그라우트의 초기강도가 고강도임을 확인하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.529-534
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• 2009

This study had propose that a characteristic of recently developed Silicasol to make a close in this study, grouting material usually used portland cement and a characteristic is compared between Silicasol and sodium silicate in this study, examined strength and environmentally friendly for compare characteristics of sodium silicate and Silicasol through unconfined compressive strength, SEM analysis, Permeability test, Chemical Resistance test, leaching test etc. In the test, I gained that unconfined compressive strength of Silicasol three times promoted than sodium silicate Within 72 hours and I gined through analysis of SEM that Silicasol is more compactivetive than sodium silicate. In the result of test, it was found to be a environmentally friendly material as the toatal amount of eluviated elementary had small quantity.

• 한국지반공학회논문집
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• 제19권1호
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• pp.163-172
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• 2003

본 연구는 최근 개발된 합성실리카 그라우트재의 공학적 특성을 규명한 것으로서 연구에 사용된 그라우트재는 보통포틀랜드시멘트를 주로 사용하였으며, 응결재인 합성실리카, 실리카졸, 규산나트륨 3호에 대한 특성을 분석하였다. 공학적 특성을 파악하기 위하여 육안관측, SEM촬영, 일축압축강도시험과 현장적용성 시험 등을 실시하였다. 이상과 같은 일련의 시험들에 의한 결과, 일반적인 규산나트륨 3호의 겔보다 합성실리카의 겔이 단시간(6～24시간)내에 일축압축강도가 3～6배정도의 고강도로 나타났다. 특히 JS-CGM Grouting에 의한 현장적용성 평가에 있어서 합성실리카 그라우트재는 차수공법용 주입재로써 상당한 투수계수 저감효과가 있음을 확인하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.453-460
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• 2005

Sodium silicate - the usual portland cement which accomplishes a cement pouring reconsideration main stream and sodium silicate(No.3) after reacting sodium silicate(No.3) with the reaction sodium silicate where oxidation natrium which is included does not react with the cement receiving stiffening water it will burn together on underwater and to become the durability lacks pouring it is recognized. From the hazard which improves an advantage it used the additive which relates in congealing and stiffening of the portland cement and sodium tripolyphosphate(STPP) addition hour initial material age(72 hours at once) which does to be revealed the at high-in-tensity is discovered while accomplishing. The effect of additives on the reactions of sodium silicate solution and cement suspesion was investigated by various physical and chemical tests, such as Si-NMR, XRD, SEM uniaxial compression test. The additives were STPP(sodium tripolyphosphate), EDTA, SUGAR. The compressive strength of sodium silicate(No.3) - cement grout with additives was about $1.5{\sim}10$ times higher than that without additive in early age(72 hours).

• Geomechanics and Engineering
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• 제21권4호
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• pp.337-348
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• 2020

Tropical organic soils having more than 65% of organic matters are named "peat". This soil type is extremely soft, unconsolidated, and possesses low shear strength and stiffness. Different conventional and industrial binders (e.g., lime or Portland cement) are used widely for stabilisation of organic soils. However, due to many factors affecting the behaviour of these soils (e.g., high moisture content, fewer mineral particles, and acidic media), the efficiency of the conventional binders is low and/or cost-intensive. This research investigates the impact of different constituents of cement-sodium silicate grout system on the compressibility behaviour of organic soil, including settlement and void ratio. A microstructure analysis is also carried out on treated organic soil using Scanning Electron Micrographs (SEM), Energy Dispersive X-ray spectrometer (EDX), and X-ray Diffraction (XRD). The results indicate that the settlement and void ratio of treated organic soils decrease gradually with the increase of cement and kaolinite contents, as well as sodium silicate until an optimum value of 2.5% of the wet soil weight. The microstructure analysis also demonstrates that with the increase of cement, kaolinite and sodium silicate, the void ratio and porosity of treated soil particles decrease, leading to an increase in the soil density by the hydration, pozzolanic, and polymerisation processes. This research contributes an extra useful knowledge to the stabilisation of organic soils and upgrading such problematic soils closer to the non-problematic soils for geotechnical applications such as deep mixing.

• 한국지반환경공학회 논문집
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• 제2권1호
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• pp.67-79
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• 2001

본 연구는 최근 개발된 마이크로 복합실리카 그라우트재의 공학적 특성을 규명한 것으로서 연구에 사용된 그라우트재는 MSG-N(완결형)을 주로 사용하였으며, 화학성분, 입도분포, 광물특성을 분석하고 응결재인 특수규산과 보통시멘트에 대한 특성도 비교 분석하였다. 공학적 특성을 파악하기 위하여 블리딩시험, 전도시험, 응결시험, 육안관측, SEM촬영, 일축압축강도시험과 매립지에 대한 현장적용성 시험 등을 심사하였다. 이상과 같은 일련의 시험들에 의한 결과 일반적인 소디움 실리케이트 그라우트보다 마이크로 복합실리카 그라우트 공법(MSG공법)이 강도적인 측면에서는 2배정도 우수하고, 알카리 용출량이 현저하게 저하되었다. 특히 MSG공법에 의한 현장적용성 평가에 있어서 매립장 침출수 차단공법으로써 침투성이 우수하고 충분한 약액의 주입에 의해 상당한 투수계수 저감효과가 있음을 알 수 있었다.

• 한국지반환경공학회 논문집
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• 제11권12호
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• pp.13-18
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• 2010

본 연구는 최근 개발된 실리카졸 그라우팅재의 환경영향성 및 내구성을 규명한 것으로써 연구에 사용된 그라우트재는 3차원 겔 형성재인 실리카졸 그라우팅제와 규산나트륨 그라우팅제에 대한 공학적 특성을 비교하기 위하여 전자현미경 촬영, 내화학성시험, 용탈시험, 투수시험 등을 통해 친환경성과 내구성을 규명하고자 하였다. 전자현미경 촬영 결과 실리카졸 그라우팅제의 표면 및 내부조직이 규산나트륨보다 치밀함을 확인할 수 있었다. 용탈시험 결과 용탈되는 원소의 총량도 극히 작아 친환경적인 재료임을 입증되어 지반주입재로써 적용성을 확인하였다. 투수시험 결과 실리카졸이 차수성면에서 현장에 적용하는데 무리가 없다고 판단되어 차수성을 요구하는 현장에 적용이 가능하다고 판단된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1195-1203
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• 2006

Water that is treated by passing through a magnetic field of certain strength is called Magnetic Field Treated Water(MFTW). Previous research indicate that use of MFTW can save 5% of cement dosage, decrease bleeding of concrete, and improve resistance to freezing. The reason why MFTW can improve characteristics of concrete can be explained by the molecular structure of water. Magnetic force can break apart water clusters into single molecules or smaller ones, therefore, the activity of water is improved. While hydration of cement particles is in progress, the MFTW can penetrate the core region of cement particles more easily. Hence, hydration takes place more efficiently which in turn improves concrete compressive strength. Test results demonstrate that the compressive strength of the sodium silicate cement grout homogel increases by approximately 20 - 50% by using the MFTW.