• Geomechanics and Engineering
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• v.15 no.6
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• pp.1143-1151
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• 2018

Loess often causes problems when used as a filling material in the construction of foundations. Therefore, the compaction technique, shear behavior, and bearing capacity of a filled foundation should be carefully considered. A series of tests was performed in this study to obtain effective compaction techniques and construction parameters. The results indicated that loess is strongly sensitive to water. Thus, the soil moisture content should be kept within 12%-14% when it is used as a filling material. The vibrating-dynamic combination compaction technique is effective and has fewer limitations than other methods. In addition, the shear strength of the compacted loess was found to increase linearly with the degree of compaction, and the soil's compressibility decreased rapidly with an increase in the degree of compaction when the degree of compaction was less than 95%. Finally, the characteristic value of the bearing capacity increased with an increase in the degree of compaction in a ladder-type way when the degree of compaction was within 92%-95%. Based on the test data, this paper could be used as a reference in the selection of construction designs in similar engineering projects.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.4
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• pp.491-497
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• 2009

The purpose of this study is to propose a method of controlling redtide microbes which grow abundantly and form harmful algal bloom in eutrophic waterbody with yellow loess and hydrogen peroxide. In the laboratory test, hydrogen peroxide was applied to single species of C. polykrikoides and multispecies of redtide microbes. The seawater was evaluated by the pre-test analysis including chlorophyll-a, luminance and transmittance. The test results showed that both single and mixed species of redtide microbes could be controlled with the dose of 30mg $H_2O_2/L$. Residual hydrogen peroxide was completely decomposed with the addition of powdered yellow loess at 2g/L~10g/L. However, the decomposition rate of residual hydrogen peroxide for sintered granular yellow loess was relatively low compared to the use of powdered one. With the addition of dissolved oxygen concentration was increased at a rate of 0.013 mg DO/mg $H_2O_2$, which is a little lower than the one predicted theoretically. No evidence for any detrimental effects on Artemia, a type of brine shrimps, was shown up to the concentration of 100mg $H_2O_2/L$.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.4
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• pp.318-327
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• 2000

Sludge production from water treatment plants is increasing each year because water resources deterioration is proceeding and water supply facilities are growing due to water demand increase. Water treatment plant sludges can be modified to soil cover in sanitary landfilling site through the lime treatment and other alternatives. The compression strength of $1.0kg/cm^2$ is necessary for the dozer operation on soft son cover material at municipal landfilling site. Modified sludge was experimentally produced in this study with lime, bentonite, loess, and activated loess dosing. X-ray diffraction patterns of the limed water treatment plant sludge confirmed the presence of calcium carbonate and ettringite. Unconfined compression strength properties of modified sludges showed material property improvement applicable for soil cover alternatives. When adding 20-30% activated loess to water treatment plant sludges. the modified sludges could reach the compression strength for cover soil after 7 days solidification reaction, but decrease of compression strength was intentioned in 28 days reaction period. Solidification effect of the modified sludge with activated loess was observed through the scanning electron microscope.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.44-51
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• 2012

In this study, hardened loess bodies, which did not compose of cement or any chemical binder, were made and tested to evaluate the physical properties such as slump, air content, and compressive strength. Addition of a natural binding material to mixture of loess and lime showed better performance in physical properties. However a lime among natural binding materials is considered as a superior binder to improve the properties of the hardened bodies. According to the experimental results, mixing proportion with 45% of W/B ratio, $285kg/m^3$ of water content, and 60% lime substitution ratio was recommended to acquire the good performance of physical properties for the hardened loess bodies.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.3
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• pp.57-63
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• 2004

This study was performed to evaluate the engineering properties of cement mortar brick with loess and fly ash. The unit weight was in the range of $2,068{\sim}2,137\;kgf/m^{3}$ and $1,899{\sim}2,045\;kgf/m^{3}$ in water and dry curing, respectively It was decreased with increasing the loess content. The absorption ratio was in the range of $5.2{\sim}13.1%$ and $8.5{\sim}13.2%$ in water and dry curing, respectively. The compressive strength was decreased with increasing the loess content. The compressive strength of the 193 $kgf/m^{2}$ in water and 188 $kgf/m^{2}$ in dry curing at the curing age 28 days of the binder volume ratio 35% was exceeded in 163 $kgf/m^{2}$ of standard compressive strength about cement bricks. The carbonation depth was in the range of $0.9{\sim}1.4$ mm, $1.2{\sim}3.6$ mm, $1.4{\sim}6.7$ mm and $2.4{\sim}12.5$ mm in dry curing of curing age 14days, 28days, 90days and 360days, respectively.

• Geomechanics and Engineering
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• v.11 no.1
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• pp.161-175
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• 2016

A series of experimental studies are conducted on the deformation and shear strength property of compacted loess. The results reveal that the relationships of both the initial moisture content (w) and the initial degree of compaction (K) of compacted loess with cohesion (w) and the angle of internal friction (${\varphi}$) are linear. The relationship between the secant modulus ($E_{soi}$) and K is also linear. The relationship between $E_{soi}$ and w can be fitted well by a second-order polynomial. Further, when the influences of w and K are ignored, the relationship between the confined compression strain (${\varepsilon}$) and vertical pressure (p) can be expressed by a formula. A correction formula for the deformation of compacted loess caused by a change in w and K is derived on the basis of the study results.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.941-944
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• 2006

Construction industry is one of the fastest growing sectors in the world. Rapid construction activity and growing demand of houses have led traditional building materials. In order to satisfy that purpose, the researchers need to vary new and innovative building materials. This paper describes the experiment carried out to investigate the elastic coefficient of loess due to compressive strength.

• Korean Journal of Human Ecology
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• v.8 no.1
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• pp.19-24
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• 2005

This paper is to know the possibility of coloration of synthetic fibers with loess. Fabrics woven with polyester, nylon, and acrylic fibers were dyed by a dip-pad operation with a laboratory mangle. Drying, curing at 180$^{\circ}C$ for 10 minutes and washing were followed. Effect of curing after drying were investigated in terms of K/S values and SEM microphotographes. Reddish-yellow(a:75.13, B:15.14, ${\Delta}$E:45.31) colored fabric ascertain possibility of coloration of synthetic fibers with loess. Acrylic fiber shows highest dye uptake of the three kinds of fibers and fastness increases by curing after drying.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.285-286
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• 2010

The purpose of this study aimed to evaluate properties of fluidity, compressive strength and bending strength of Loess mortar using non-cement binder to solve indentation due to reduction of compressive strength on exiting Loess bicycle load.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.287-288
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• 2010

The purpose of this study aimed to evaluate properties of water resistance, disease of freezing and thawing and XRF of Loess mortar using non-cement binder to solve reduction of durability by freezing and thawing on exiting Loess bicycle load.