• Journal of the Korean GEO-environmental Society
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• v.11 no.4
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• pp.5-12
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• 2010

Soil mixture using bentonite as a cutoff material is used a lot for various structures such as landfills, banks and dams as cutoff materials. But seepage water is expected to seep since shear failure of filter layer occurs due to external load, embankment load when constructed. Generally, only coefficient of permeability of Soil Mixture is considered irrespective of the changes of intensity on amount of additives. This research is to study on how the changes of amount of bentonite affects permeability and strength of soil mixture. So successive experiments for measuring permeability and strength were conducted as the amount of bentonite changes from 0 to 4%, mixing with the bed material and then making specimens. Around construction site of B dam. As a result, 2.085E-07 cm/sec was shown when the amount of Soil Mixture was 4%. It is proved that unconfined compressive strength and tensile strength increase as the amount of bentonite increases, but saturation shear strength of bentonite soil mixture from the CD experiment is hardly influenced by the amount of bentonite.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.17-23
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• 2004

Strength and deformation characteristics of oyster shell-sand mixtures were investigated to utilize waste oyster shell being treated as a waste material. Standard penetration test (SPT) is a common method to obtain in-situ strength in sand. However, in case of oyster shell-sand mixtures, there was no information between SPT N-value and internal friction angle of mixture soils. In this paper SPT experiments from several large scaled model chamber tests and large scaled direct shear tests were carried out with varying unit weight of oyster shell-sand mixtures. Appropriate correlations were in tile study observed among N-value, unit weight and internal friction angle, which make it possible to estimate in-situ strength from SPT and the coefficient of volume compressibility from the confined compression tests to compute the settlement of oyster shell-sand mixtures.

• Journal of the Korean GEO-environmental Society
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• v.20 no.5
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• pp.47-55
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• 2019

This study aims to provide basic data for soil packaging differing in accordance with the strength characteristics of mixed soil, using E.S.B. (Eco Soil Binder), an eco-friendly hardening agent, based on the type of soil. The soil used in this study is weathered granite soil readily collected in and around Korea, and is classified into SW, SP and SC according to soil classification systems. The test piece for the unconfined compressive strength test has dimensions of 50 mm in diameter and 100 mm in height, with the mix ratio of E.S.B. proportional to the weight of mixed soil changed from 5% to 10%, 15%, 20%, 25%, and 30%, where compactness of 90% and 100% were applied according to each condition to analyze the unconfined compressive strength characteristics at material ages of 3, 7, and 28 days. Also, the ratio of soil packaging standard strength and unconfined compressive strength was calculated to determine the optimal E.S.B. mix ratio, whereby the field applicability of the unconfined compressive strength using the estimation equation of ACI209R was evaluated.

• Journal of the Korean Geotechnical Society
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• v.26 no.4
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• pp.15-26
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• 2010

To determine the frost heave suppressing mechanism of soil mixed with tire powder, we conducted three kinds of laboratory experiments: measurement of unfrozen water, evaluation of thermal conductivity, and a frost heave. In this research, we focused on changes in the coefficient of permeability of the mixed soil, and first found that of the unsaturated soil. Next, in the case of the presence of ice, we took the ice-impeding factor into consideration to derive the coefficient of permeability of the frozen fringe from the area ratio of the soil and tire powder in mixed soil. The results show a positive correlation between the water intake rate and the coefficient of permeability. Moreover, we found that the frost heave decreased thanks to a reduction in the permeability and a fall in the unfrozen water content of the soil mixed with tire powder. We also calculated the weight of the water content of the soil and tire powder void quantitatively using the result of the volumetric ratio of mixed soil.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.708-711
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• 2010

본 연구에서는 경량혼합토 배합설계변수인 원료토의 중량, 함수비 및 기포재와 첨가할 물의 양, 그리고 강도를 발현하기 위하여 필요한 고화재로서 시멘트첨가량에 대한 최적의 배합설계에 대한 분석을 하였다. 분석을 위해 폐타이어가루와 왕겨를 각각 혼합한 경량혼합토의 압축강도를 비교 분석하였다. 왕겨혼합토는 함유량 3%에서 최대강도가 발현되는 반면 폐타이어혼합토의 경우 함유량 6%에서 최대강도를 보여주었다. 현장에서 설계기준을 만족하기 위한 시멘트비와 폐성분을 적절히 혼합하면 합리적이고 경제적인 배합비를 산출할 수 있다.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.51-60
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• 2001

연안역 굴양식장에서 발생하여 폐기물로 분류되어 불법으로 버려지는 굴패각을 파쇄하여 혼합한 모르타르 혼합토의 특성을 규명하고자 압축강도 시험을 포함한 다양한 실내시험을 수행하였다. 압축강도시험을 위하여 준비한 모르타르 공시체는 시멘트, 물, 모래 및 굴패각을 다양한 배합비로 혼합하여 제작하였다. 강도시험결과에 따르면 분쇄한 굴패각의 비율이 최대 모래중량의 40%까지 혼합한 경우에도 굴패각을 섞지 않은 일반 모르타르 혼합토에 비하여 압축강도가 크게 감소하지 않았다. 본 연구에서 수행한 압축강도실험을 분석한 결과, 다양한 크기로 파쇄한 굴패각을 적절한 혼합비의 모래 및 시멘트와 배합하여 사용한다면 건설재료로서의 재활용 가능성이 충분한 것으로 판단되었다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.229-235
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• 2018

In this study, recycled aggregate and natural aggregate were mixed in advance using an aggregate mixing facility that was developed to improve the quality of recycled aggregate concrete. Then the mixed aggregate was applied and concrete characteristics before and after a mix were considered. Based on the findings extracted, this study aimed to suggest a new direction for quality stabilization and application activation of recycled aggregate. The test results of change rates of mortars and coarse aggregates in fresh concrete mixed by a concrete mixer, before and after mixing aggregates showed that the variations of the mortars and coarse aggregates in the concrete mixed with the aggregates beforehand were decreased than those in the concrete before mixing them. The variation of compressive strength and the mean compressive strength at the ages of 3 and 7 days showed similar results before and after the aggregates were mixed, and the strength at the age of 28 days before and after mixing them showed larger deviation than that at the ages of 3 and 7 days. The use of the mixed aggregates after mixing aggregates beforehand reduced the variation in strength and is believed that it is advantageous for long-age strength development. The above results show that the variations of coarse aggregates and compressive strength in the concrete using the mixed aggregates produced by mixing recycled aggregates and natural aggregates beforehand are reduced so it will be possible to produce the homogeneous concrete by mixing aggregates beforehand.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.258-261
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• 2001

The paper industry produces about 6,000 ton of paper ashes yearly with by-products in Yuhan-Kimberly Ltd. The paper ashes was analyzed and evaluated for their potential as the soil acidity amendment materials. This study was conducted to investigate a reasonable amount of paper ashes for soil acidity amendment effect to be applied onto raising seedling of Calendula officinalis L. The mixed proportion of applied ashes, which was compared with agricultural lime, was treated to 0, 5, 10 and 15% (v/v) in mixed soil (pH 6.0) and the peat moss (pH 3.8) respectively. Consequently paper ashe was found to be more effective than agricultural lime at germination percentage, growth condition and in sharp initial increase of soil pH. The appropriate proportion of applied paper ash was 10% (v/v) at the soil-mix, and 15% (v/v) at the peat-moss. Soil application of paper ashes may provide supplemental quantities of K, Ca, Mg and other plant nutrients. But heavy metal concentrations in paper ash was low and should not limit application rates.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.5-11
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• 2006

The purpose of this study was to examine the proper mixing ratio of ordinary portland cement and Bottom Ash to recycle the Bottom Ash, which is an industrial waste. After the evaluation, the compressive strength and durability were assessed using the mixture of completely weathered soil (Hwangto), weathered granite soil, and Bentonite. Then environmental friendliness of this mixed material was examined through heavy metal leaching method. It was found out that proper mixing ratio is 6:4, and that the 6% mixture quantity of completely weathered soil (Hwangto), weathered granite soil, and Bentonite is the most effective for compressive strength and durability It was also found out through heavy metal leaching method that the Bottom Ash could be below the standard of the Clean Water Law.

• The Korean Journal of Ecology
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• v.20 no.5
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• pp.385-391
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• 1997

To investigate the degrees of toxification in the serpentine areas, serpentinites and adjacent metamorphic rocks and soils from the serpentinite, metamorphic area and transitional area(mixed soil) between serpentinite and metamorphic rocks are collected from the Hongseong-Gun, Chungnam. A plant, Geochemically, the serpentinites are high in the nickel, chromium and cobalt content whereas the metamorphic rocks show high zinc, scandium, molybdenum and iron contents. The serpentine soils are high in the nickel, chromium and cobalt contents whereas the non-serpentine soils show high zinc and iron contents. Heavy metal contents in the G. oldhamiana are high in the serpentine soil relative to the mixed soil. Ratio of the iron to nickel contents for the G. oldhamiana are low in the serpentine soil(49) relative to the mixed soil(216). Of the G. oldhamiana, most of the heavy metal contents except zinc and molybdenum are high in the root relative to the aboveground vegetation. Comparing with rocks, the G. oldhamiana is low in the all of heavy metal contents relative to the serpentinite. Uptake of zinc by the G. oldhamiana is high in the serpentinites and metamorphic rocks whereas uptake of scandium and iron by the G. oldhamiana is very high in the serpentinite area.