• Title/Summary/Keyword: 천연모래

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A Study on the Treatment of Petroleum-Contaminated Soils Using Hydrogen Peroxide (석유로 오염된 토양의 과수를 이용한 처리에 관한 연구)

  • 최진호;김재호;공성호
    • Journal of Korea Soil Environment Society
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    • v.2 no.3
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    • pp.49-57
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    • 1997
  • Naturally-occurring iron minerals, goethite and magnetite, were used to catalyze hydrogen peroxide and initiate Fenton-like oxidation of silica sand contaminated with diesel, kerosene in batch systems. Reaction conditions were investigated by varying H$_2$0$_2$concentration(0%, 1%, 15%), initial contaminant concentration(0.2, 0.5, 1.0g diesel and kerosene/kg soil), and iron minerals(1, 5wt% magnetite or goethite). Contaminant degradations in silica sand-iron mineral-$H_2O$$_2$ systems were identified by determining total petroleum hydrocarbon(TPH) concentration. In case of silica sand contaminated with diesel(1g contaminan/kg soil with 5wt% magnetite) addition of 0%, 1%, 15% of $H_2O$$_2$showed 0%, 25%, and 60% of TPH reduction in 8 days, respectively When the mineral contents were varied from 1 to 5wt%, removal of contaminants increased by 16% for magnetite and 13.1% for goethite. The results from system contaminated by kerosene were similar to those of the diesel. Reaction of magnetite system was more aggressive than that of goethite system due to dissolution of iron and presence of iron(II) and iron(III); however, dissolved iron precipitated on the surface of iron mineral and seemed to cause reducing electron transfer activity on the surface and quenching $H_2$$O_2$. The system used goethite has better treatment efficiency due to less $H_2$$O_2$ consumption. Results of this study showed possible application of catalyzed $H_2$$O_2$ system to petroleum contaminated site without addition of iron source since natural soils generally contain iron minerals such as magnetite and goethite.

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The Effect of KOB-Soil as a Soil Amendment on Turfgrass Growth (종합 토양개량재 KOB-Soil이 잔디 생육에 미치는 영향)

  • 이상재
    • Asian Journal of Turfgrass Science
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    • v.17 no.1
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    • pp.13-17
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    • 2003
  • This study was conducted to figure out the effect of KOB Soil on creeping bentgrass‘Cobra’, Kentucky bluegrass (KB)‘Midnight’75% + Perennial ryegrass (PR)‘Palmer III’25%. This experiment was conducted from September 1, 2001 to August 31, 2002 at Hwajoulryong in Jeongsun County, Gwangwon-do. Treatments were Sand 80% + Peatmoss 20%, Sand 80% +KOB-Soil (No. 1) 20%, and Sand 80% +KOB-Soil (No. 2) 20%. Treatments with KOB Soils was superior to control fer the leaf length, number of leaf, turf quality and root length in Creeping bengrass and Kentucky bluegrass + Perennial ryegrass.

GIS-based Network Analysis for the Understanding of Aggregate Resources Supply-demand and Distribution in 2018 (GIS 네트워크 분석을 이용한 2018년 골재의 수요-공급과 유통 해석)

  • Lee, Jin-Young;Hong, Sei Sun
    • Economic and Environmental Geology
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    • v.54 no.5
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    • pp.515-533
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    • 2021
  • Based on the supply location, demand location, and transportation network, aggregate supply-demand characteristics and aggregate distribution status were analyzed from the results of the closest distance, service areas, and location-allocation scenarios using GIS network analysis. As a result, it was found that the average transport distance of aggregates from the supplier was 6 km on average, the average range of 7 km for sand, and 10 km for gravel was found to reach the destination. In particular, the simulated service area covers about 92% in Seoul-Gyeonggi Province, 85% in Busan-Ulsan-Gyeongnam Province, and more than 90% in Daejeon-Sejong-Chungnam Province. These results have a significant implication in quantitatively interpreting primary data on aggregate supply-demand. Furthermore, these results suggest the possibility of a wide-area quantitative analysis of aggregate supply regions necessary for establishing a basic aggregate plan. The results also evaluated by the site-allocation scenario show that aggregate supply may be possible through companies less than 200 with large-amounts quarries, which is the 700 companies currently supplying small amounts of aggregates on the country. Therefore, in terms of distribution of aggregates, a policy approach is needed to form an appropriate market for regions with high and low density of aggregate supply services, and the necessity of regional distribution and re-evaluation is suggested through an aggregate supply analysis demand across the country. Furthermore, in analyzing the supply-demand network for the aggregate market, additional research is needed to establish long-term policies for the aggregate industry and related industries.

Thermal Conductivity of Sand-Tire Rubber Mixtures According to Degree of Saturation: Effect of Hydrophobic Particles (포화도에 따른 모래-타이어칩 혼합토의 열전도도 변화: 입자의 소수성 영향)

  • Oh, Jiseok;Choo, Hyunwook
    • Journal of the Korean Geotechnical Society
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    • v.40 no.4
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    • pp.7-18
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    • 2024
  • Because of their mineral composition, tire chips have very low thermal conductivity compared with natural geomaterials, leading to the use of sand-tire rubber mixtures in thermally insulating applications. However, systematic studies evaluating factors affecting the thermal conductivity of sand-tire rubber mixtures have been very limited. Thus, this study investigated the thermal conductivity of sand-tire rubber mixtures with varying size ratios and tire chip fractions according to the degree of saturation (S). Specimens were prepared in insulated cells, and thermal needle probe tests were performed. In addition, the contact angle and solid surface free energy of sand-tire rubber mixtures were investigated. The results of this study revealed that the thermal conductivity decreased with increasing tire chip fraction but increased with increasing water content (or S). However, the trend of increasing thermal conductivity with S varied with the tire chip fraction, and the specimens with tire chip fraction > 0.4 clearly showed a delayed increase in thermal conductivity with increasing S. This reflected that hydrophobic particles (tire chip) affected the dependency of thermal conductivity on S because of the delayed formation of capillary water bridges, which served as additional thermal conduction paths with increased moisture content.

Properties of Non Sintered Cement Mortar using Ferro Nickel Slag (페로니켈 슬래그를 사용한 비소성 시멘트 모르타르의 특성)

  • Youn, Min-Sik;Na, Hyeong-Won;Hyung, Won-Gil
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.6
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    • pp.641-649
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    • 2022
  • This study aims to completely develop a non sintered cement mortar using industrial by-products. To replace Portland cement, blast furnace slag, circulating fluidized bed fly ash, and pulverized coal fly ash were used, and natural aggregates were substituted with ferronickel slag. To understand the characteristics of the non sintered cement mortar to which ferronickel slag is applied, an experiment was conducted by classifying the particle size. Fluidity and workability were confirmed through the flow test, and bending and compressive strength tests were conducted at 3, 7, and 28 days of age. In addition, durability was identified through a chloride ion penetration test. Through the study, it is judged that the binder, which completely replaced cement and aggregate, has high potential of being used as a construction material. Notably, it was confirmed to be advantageous for strength and durability.

Effect of Ferro-nickel Slag on Contamination of Soil and Water (페로니켈슬래그(FNS)가 토질 및 수질오염에 미치는 영향)

  • Park, Kyungho;Kim, Daehyeon;Kim, Byungho;Go, Youngjin
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.4
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    • pp.21-33
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    • 2013
  • The purpose of the study is to evaluate engineering properties of Ferro Nickel Slag (FNS) and to investigate the effects of FNS on potential contamination of surrounding soil and water through small and large chamber tests. Soil conditions in the chamber tests were made as closely as possibile to the field conditions. In order to simulate different types of water, we used fresh water, acidic water and seawater. Sand soils were made with relative densities of 40% and 60%, and clay with the degree of compaction of 90%. After flushing water through the FNS in the chambers was completed, the PH test was performed for the water flowing out of the chambers and the soil samples were collected for soil pollution analysis. Based on the results of the chamber tests, although the pollution level was slightly higher in the silt than in the sand, the environmental effect that FNS causes the surrounding soil was found to be very minimal. This indicates that FNS can be used as construction material in place of natural aggregates.

An Experimental Study for Substitutability of Sand Mat with Precious Slag Ball (풍쇄 슬래그의 샌드매트 대체 가능성에 대한 실험적 연구)

  • Shin, Eun-Chul;Lee, Woon-Hyun;Kang, Jeong-Ku
    • Journal of the Korean Geosynthetics Society
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    • v.9 no.2
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    • pp.1-9
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    • 2010
  • At present, the sand mat method is actively used for improvement of soft ground. But, there are some problems related with sand mat which has been used as a way to accelerate consolidation settlement. First of all, insufficiency of sand due to imbalances in market supply and demand is the one of the biggest problems, which makes price high of sand and delays a term of total construction work. Moreover, it is necessary to preserve integrity of environment from natural disruption caused by indiscreet quarrying and dredging operation to supply sand for soil improvement construction site. This paper presents the feasibility study to use of Precious Slag Ball instead of sand mat as the replacing material through the basic soil property tests, the medium of discharge capacity test and analysis of settlement property. It is also evaluates the performance of Precious Slag Ball as a sand mat in terms of discharge capacity, ground settlement by the K-Embank program based on field experimental work.

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Discharge Capacity of Environmentally Friendly Drains (친환경배수재의 통수능 특성 평가)

  • Cho, Sam-Deok;Kim, Ju-Hyong;Jung, Seung-Yong
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.1
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    • pp.27-36
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    • 2005
  • Discharge capacity of the fiber mat and the fiber drain made with natural fibers abstracted from plant source was evaluated by permeability test for fiber mat and Delft type test and composite discharge capacity test using disturbed clayey soils for fiber drain. The permeability test results for environmentally friendly coconut fiber mat prove that fiber mat has outstanding permeability in substituting permeable sand. However, discharge capacity of fiber drain evaluated by conventional Delft type discharge capacity test was relatively lower than that of plastic drain board. Nevertheless, settlement and pore pressure dissipation behaviors of fiber drain and plastic drain board installed clay soil during the composite discharge capacity test were almost similar to that of plastic drain board. It is found that the natural fiber drain satisfies requiring minimum discharge capacity in substituting the conventional plastic drain board.

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Proposals for Revision of Lightweight Aggregate Concrete Specifications Based on In-situ Quality Control on Concrete (현장 품질관리를 고려한 경량골재 콘크리트의 시방서 개정안에 대한 고찰)

  • Lee, Kyung-Ho;Yang, Keun-Hyeok
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.3
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    • pp.211-218
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    • 2018
  • This study examined the reliability and revision necessity of concrete standard specifications based on the comparisons with test data obtained by using domestic artificial lightweight aggregates and the contents specified in different foreign specifications including ACI 211.2, ACI 213, ACI 301, JASS 5 and CEB-FIP. To achieve the continuous particle distribution of domestic fine lightweight aggregates, the partial addition of natural sand with the maximum size of 2.5mm was required. To control the segregation and excessive bleeding in the fresh lightweight concrete, the current limitations on the water-to-binder ratio and unit water content need to be modified using lower values. In particular, a rational mixture proportion approach of lightweight concrete needs to be established for the targeted requirements of initial slump, 28-day compressive strength, air content and dry unit weight. Ultimately, significant revision of the concrete standard specifications is required considering the characteristics of domestic artificial lightweight aggregates.

A Study on the Development Lightweight Aggregate using Recycled-Paint for Reduction in Freezing Ground (단열골재 개발을 통한 동토방지 기술개발에 관한 연구)

  • Moon, Jong-Wook;Back, Min-Ho
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.4
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    • pp.47-54
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    • 2010
  • This study is progressed function ratio, it's trued taste by an experiment to present data for human work light weight aggregate development that use clink ash progressed liquid limit, small success limit, wear loss in quantity, sand equivalent, sieve cutting examination. 80:20's match of function rain examination is 1.4, and that use rubble aggregate as recyeled-panit lightweight aggregate's capacity ratio increases by 1.0 increase of function rain many. Also, examination multiplied delicate flavor gradually according to increase of the mixing rate, and absorption coefficient increased. This is judged by phenomenon that appear by special quality upper recycled-panit of polystyrene bid and porosity's increase between lightweight aggregate. It is case that use aggregate of wear loss in quantity is 13.5 in sand equivalent and a wear loss in quantity experiment and although case that mix 20% increases by 14.4, this phenomenon by weak tissue of lightweight aggergate be judged. When it's as a these experiment, the statue prevention floor of a street improvement specifications is prescribing so that satisfy by sand equivalent 20, CBR 10. This is showed result that this satisfies in quality standard all in match experiment ago that see.