• 한국지반공학회논문집
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• 제27권3호
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• pp.19-26
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• 2011

본 연구에서는 유기물이 혼합된 사질토와 점성토의 다짐특성을 파악하기 위하여, 사질토로는 풍화토를, 점성토로는 카오리나이트를, 유기물로는 석탄을 사용하여 혼합토를 만들고 다짐시험을 실시하였다. 또한 다짐시험시 계면활성제의 일종인 비눗물을 물 대신에 사용하여 다짐특성의 차이를 검토하였다. 유기질 풍화토에서 비눗물을 사용해 다짐시험을 하는 경우 물을 사용하여 다짐시험을 하는 경우와 마찬가지로 유기물함량이 클수록 최적함수비는 증가하고 최대건조단위중량은 감소하였다. 유기질 풍화토에서 작은 다짐에너지를 사용하는 경우에는 물 대신에 비눗물을 사용하면 다짐효과가 다소 증진하는 것으로 나타났다. 유기질 점성토에서는 비눗물을 사용해 다짐시험을 하는 경우 물을 사용하여 다짐시험을 하는 경우와 마찬가지로 유기물함량이 클수록 최적함수비는 감소하고 최대건조단위중량은 증가하였다. 유기질 점성토에서는 다짐에너지의 크기에 관계없이 물 대신에 비눗물을 사용하면 다짐효과가 다소 증진하는 것으로 나타났다.

• 한국환경복원기술학회지
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• 제5권6호
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• pp.37-42
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• 2002

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with polypropylene fiber, and to confirm the reinforcing effects with admixture such as polypropylene fiber. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and polypropylene fiber reinforced soil. In order to determine proper moisture contents and mixing ratio, pilot test was carried out for natural soil and PFRS(polypropylene fiber reinforced soil). And the mixing ratio of mono-filament fiber and fibrillated polypropylene fiber admixture was 0.1%, 0.3%, 0.5% and 1.0% by the weight of dry soil. From the experimental results, it was found that the optimum moisture contents(OMC) increased with the mixing ratio of fiber, but the maximum dry unit weight and the volume change was decreased with the mixing ratio. It means that the improvement of the workability and the reduction of the weight of embankment was done by the addition of the polypropylene fiber. And, from the compression test results, it was found that the addition of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil was more effective than the mono-filament polypropylene fiber reinforced soil.

• 한국지반환경공학회 논문집
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• 제16권8호
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• pp.13-20
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• 2015

인구가 증가하고 자원이 고갈되면서 새로운 자원개발을 위한 대안으로 극한지 개발이 떠오르고 있다. 전 세계 육지 면적 중 14%가 극한지 지역에 해당되며, 이 지역들의 개발을 위한 해외극지 건설시장이 많이 확대되었다. 이미 선진국들은 극한지 연구의 필요성을 인식하고 기술 개발에 많은 투자를 하고 있는 반면, 우리나라의 경우 극한지 개발을 위한 기술이 선진국에 비해 매우 낮으며 관련 연구 또한 미약한 실정이다. 국내의 동절기 시공의 경우 지반동결에 의한 강도 및 변형특성에 대한 명확한 기준이 마련되어있지 않으며 현장에서의 간단한 지침을 통해서만 관리되고 있다. 따라서 본 연구에서는 상온($18^{\circ}C$), $-3^{\circ}C$, $-8^{\circ}C$에서 세립분 함량을 0%, 5%, 10%, 15%로 변화하면서 D 다짐 시험을 실시하여 영하온도에서의 다짐특성에 대해 살펴보았으며, 기존의 문헌연구와 비교를 통해 영하온도에서의 다짐에너지에 따른 다짐 효과에 대해 평가하였다. 시험 결과 영하온도에서 다짐에너지가 클수록 최대건조단위중량은 증가하는 것으로 나타났으며, $-3^{\circ}C$에서의 D다짐 시험결과는 상온의 결과와 크게 다르지 않으나 $-8^{\circ}C$ 이하에서의 다짐시공 시 다짐성능의 저하가 상당한 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.631-636
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• 2002

This study shows basic data for using as the structural lightweight aggregate. This will be the procedural method of recycling environmental close waste PET bottle lightweight aggregate(PBLA) that is rapidly increased the amount of production of waste PET bottle recently, the quality of developed PBLA and the fundamental properties by analyzing of mortar containing with PBLA. After experiment, the result shows the PBLA quality that have oven dry specific gravity of 1.39, unit volume weight of 844 kg/m$^3$ and absorption rate of 0% is satisfied with qualify regulation of lightweight aggregate. The flowability of mortar containing PBLA is increased maximum 16% with increasing mixing ratio of PBLA, however the compressive strength of mortar is decreased maximum 35% with increasing mixing ratio of PBLA.

• 한국농공학회지
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• 제41권5호
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• pp.93-98
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• 1999

The results of an experimental investigation on the characteristics of compaction and compressive strength of polypropylene fiber reinforced soil are presented in this paper. This study has been performed to obtain the physical properties of PFRS(polypropylene fiber reinforced soil) such as strain-stress relationships, OMC(optimum moisture contents) and ${\gamma}$dmax (maximum dry unit weight), with four different contents (i.e., 0.1%, 0.3%, 0.5% and 1.0% weights ) of mono-filament and fibrillated polypropylene fibers. From the compaction test results, it is found that OMC increased with the contents ratio of fiber, but ${\gamma}$dmax decreased. It means that the improvement of the workability and the reduction of the weight of embankment structures by the asddtion of the polypropylene fiber. And, from the compression test results, it is found that the additon of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil is more effective than the mono-filament polypropylene fiber reinforced soil.

• 지질공학
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• 제14권2호
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• pp.199-210
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• 2004

본 연구는 전라남도 화순군에 분포하는 셰일 풍화토를 대상으로 실험실에서 물성 및 역학 시험을 실시하여 풍화토의 물리적ㆍ역학적 특성을 파악하였다. 연구지역 셰일 풍화토의 물리적 특성인 비중, 액성한계, 소성한계 및 소성지수는 각각 2.66~2.68, 36.39~36.92(%), 18.53~19.48(%), 17.44~17.86 이며, 흙의 분류는 CL에 해당된다. 다짐시험결과 최적함수비는 22.5~23% 최대 건조단위중량은 $1.58~1.61t/\textrm{m}^3$으로 나타났다. 전단시험 결과 포화 및 불포화시료의 경우 건조단위중량이 커질수록 점착력은 증가하는 경향이 나타났고, 불포화 상태의 점착력이 포화 상태의 점착력의 약 2배 정도 크게 나타났다. 마찰각의 경우, 불포화 상태일 때는 건조단위중량이 증가할수록 증가하는 경향이 나타나지만, 포화 상태의 경우는 건조단위중량이 증가할수록 감소하다가 다시 증가하는 경향을 보였다. 대구지역 셰일 풍화토(김 등, 1995)의 공학적 특성과 비교할 때, 비중은 유사하지만 액성한계 및 소성한계는 약간 높은 것으로 나타났다.

• 한국환경과학회지
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• 제22권2호
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• pp.187-193
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• 2013

Dry matter allocation characteristics of Calystegia soldanella, grown in pots, was analysed to assess its plasticity in response to water-stressed conditions. As water was withheld leaf water potential between the two watering treatments was similar during the first 6 days, followed by a rapid decrease in water-stressed plants. The minimum leaf water potential was -1.50 MPa on day 15 and the maximum leaf water potential was about -0.5 MPa on day 0 in water-stressed plants. In well-watered plants leaf water potential was maintained almost consistently throughout the experiment. There was no significant difference in plant dry weight between the two watering treatments for 9 days after the start of experiment and that was remarkably increased thereafter, compared with that remained without any increase in water-stressed plants. In dry mass partitioning, however, the water-stressed plants showed a great plasticity, showing that there were 1.81, 1.35 and 0.81 times increase in root, stem and leaf, respectively. Dry mass partitioning in well-watered plants varied from 2% to 5%. The difference of dry mass partitioning between the two watering treatments was reflected in leaf mass per unit area (LMA) and root/shoot (R/S) ratio. LMA in water-stressed plants was lower than that in well-watered plants, while R/S ratio in water-stressed plants was higher in well-watered plants. This means that the water-stressed plants reduced its leaf area and increased dry mass partitioning into root and stem during the progress of soil drying. These results indicate that Calystegia soldanella inhabiting in sand dune cope with water stress with high plasticity which can adjust its dry mass partitioning according to soil water conditions.

• Geomechanics and Engineering
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• 제18권2호
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• pp.179-188
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• 2019

This paper presents an experimental study to evaluate the effect of palm oil on the selected basic physical-chemical and geotechnical properties of kaolin. The experimental findings are further compared with literature outcomes investigating similar properties of fine grained soils subjected to contamination by different types of oils. To this end, palm oil was mixed with oven dried kaolin samples-aiding oil's interaction (coating) with dry particles first, in anticipation to emphasize the effect of oil on the properties of kaolin, which would be difficult to achieve otherwise. Oil content was limited to 40% by dry weight of kaolin, supplemented at intervals of 10% from clean kaolin samples. Observations highlight physical particle-to-particle bonding resulting in the formation of pseudo-silt sized clusters due to palm oil's interaction as evinced in the particle size distribution and SEM micrographs. These clusters, aided by water repellency property of the oil coating the kaolin particles, was analyzed to show notable variations in kaolin's consistency-measured as liquid and plastic limits. Furthermore, results from compaction tests indicates contribution of oil's viscosity on the compaction behavior of kaolin - showing decrease in the maximum dry unit weight (${\gamma}_{d,max}$) and optimum moisture content ($w_{opt}$) values with increasing oil contents, while their decrease rates were directly and inversely proportional in ${\gamma}_{d,max}$ and $w_{opt}$ values with oil contents respectively. Comparative study in similar terms, also validates this lower and higher decrease rates in ${\gamma}_{d,max}$ and $w_{opt}$ values of the fine grained soils respectively, when subjected to contamination by oil with higher viscosity.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.444-448
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• 1998

This paper presents the results of an experimental investigation on the compaction and compressive strength of polypropylene fiber reinforced soils. This study has been performed to obtain the physical properties of PFRS(polypropylene fiber reinforced soil) such as strain-stress relationships, OMC(optimum moisture contents) and ${\gamma}$$_{dmax}$ (maximum dry unit weight), with four different concentrations(i.e., 0.1%, 0.3%, 0.5% and 1.0% weights) of mono-filament and fibrillated polypropylene fibers. The test results indicate an appreciable increase in strength due to addition of fibers. OMC is increased with the concentration ratio of fiber, but ${\gamma}$$_{dmax}$ is decreased. From the viewpoint of strength, the fibrillated polypropylene fiber soil is more effective than the mono-filament polypropylene fiber soil.oil.

• 한국안전학회지
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• 제14권4호
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• pp.135-141
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• 1999

This study is an experimental study to investigate the possibility of the utilization of paper ash as the cover, liner in waste disposal landfill and other construction materials. The sample used in these tests was obtained from Daehan paper mill. A series of tests were peformed to evaluate basic properties, compaction, permeability, compressive strength, consolidation, leaching, and CBR of paper ash. In order to investigate the soil engineering properties of paper ash, the test results were compared with those obtained of fly ash. The results of unconfined compression tests show that paper ash had a larger strength than the fly ash. Also, the maximum dry unit weight of paper ash was approximately 59～76.9% less than that of the fly ash. It was found from the results of leaching test that paper ash is classified as non-detrimental general wastes according to the waste management law.