• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.24-31
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• 2004

A cold mix asphalt (CMA) treatment process was proposed as a tool to recycle soils contaminated with petroleum hydrocarbons. Experimental studies were conducted to characterize performances of the CMA process in treating soils contaminated with diesel or diesel compounds. From the screening experiments, it was found that performances of five types of asphalt emulsions that contained a cationic or an anionic or a nonionic surfactant were not substantially different. In consideration of higher affinity for soils and higher sorption coefficients obtained, an emulsion containing Lauryl Dimethyl Benzyl Ammonium Chloride (LDBAC) was selected as a promising asphalt emulsion for treating diesel-contaminated soils. When the asphalt emulsion LDBAC was applied to treat three compounds that originated from diesel, the removal efficiencies obtained in the order of decreasing efficiencies were as follows: docosane > pentadecane > undecane. Leaching experiments on the specimen formulated by the emulsion LDBAC found that the selected treatment method could treat soils with diesel concentrations as high as 10,000 mg/kg. Leaching of the diesel from the specimen was controlled by diffusion for the first four days and then leaching rate diminished substantially. The latter behavior was characterized as depletion, which represents that the contaminant released amounts to more than $50\%$ of the total amount of the contaminant that can be leached. The amounts of three diesel compounds leached from the specimen in the order of decreasing amount were undecane, pentadecane, and docosane. The curing of the soil contaminated with pentadecane was relatively slow.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.29-40
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• 2011

Warm-Mix Asphalt(WMA) technologies have been developed since 15 years ago, which are internationally and domestically concerned with energy-saving and environmental-friendly technologies in public and private sectors of highway engineering. The performance of asphalt mass is traditionally evaluated by the penetration, viscosity, or Superpave tests. This research, however, is focused more on the properties depending on asphalt film thicknesses instead of evaluating asphalt mass behaviors by those tests. For this approach, a new testing protocol and analysis method are described by the bonding properties on each film thickness. This testing method and analysis tool are borrowed from those of DSR Moisture Damage test and applied by using ARES. The analysis results indicate that there is a limit film thickness between $200{\mu}m$ and $400{\mu}m$, which causes significant changes of the properties. In addition, the results show that the property changes of Hot-Mix Asphalt(HMA) and WMA on the limit film thickness are also different. Therefore, it is suggested that the properties on thin film thicknesses between $200{\mu}m$ and $400{\mu}m$ should be considered in order to evaluate WMA properly.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.227-232
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• 1994

Recently, TBM (Tunnel Boring Machince) method for a tunnel construction in domestic is very promisible due to shorten a constrution period. It is very important to increase the efficiency of the shotcrete for the TBM. The major factors influencing the efficienty of shotcrete are materials, mix disign, constrution conditions and skill of nozzle-man. In this paper, first, optimum synthesize conditions for the shotcrete accelerators was explored and early stiffenting mechanisms also studied. Second, TBM method was applied for a real job site using the optimum conditions obtained from a lab scale experiment.

• IE interfaces
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• v.1 no.1
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• pp.1-7
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• 1988

This paper discusses the applicability of the decomposition principle to an LP (Linear Programming) problem. Through a case study on product mix problems in a chemical process of Korean Steel Chemical Co., Ltd., the decomposition algorithm, LP Simplex method and a modified method are compared and evaluated in computation time and number of iterations.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.135-143
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• 2006

This study evaluated the fatigue resistance characteristics of hot-mix recycled asphalt mixtures which were prepared by a new blending method. Since the binder of RAP shows higher viscosity without being rejuvenated in the ordinary recycled mixture, this new(modified) blending method was developed for obtaining more uniform level of binder viscosity in the recycled mixture. Cold-planned RAP was collected and mix design was performed using 15% RAP content for two virgin aggregate, gneiss and granite. Penetration grade of 60-80 asphalt was used in mixing recycled mixture together with a polymer modifier, LDPE. Indirect tensile fatigue tests were carried out to evaluate characteristics of fatigue resistance of performance of recycled asphalt mixtures. The recycled mixtures with LDPE 6% showed higher repeated loading fatigue life. Fatigue life ratio of new(N) mixing method mixtures was approximately 0.6-0.7 before aging and 0.8-1.0 after aging treatment of ordinary(O) mixing method mixture. This means the N mixture becomes stronger with aging process increase. If further aging is treated, N mixture may be showing stronger resistance than O mixture.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.290-302
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• 2023

The aim of this study was to examine the changes in the initial tree growth characteristics of Q. variabilis planted in forest fire-damaged areas treated with soil moisturizers such as biochar and to identify the factors that affect tree growth. To evaluate the effectiveness of soil moisture treatment in the area planted with QV, an experimental plot was created according to the treatment method (spread and mix) and treatment ratio (0, 4, and 40 t/ha). The survival rate of QV was 20% higher in the treatment plot than in the control plot. The height and root collar diameter (RCD)growths of QV were high on the northern slope with spread treatment and on the southern slope with mix treatment. The relative growth rate (RGR) according to the soil moisturizer treatment method was higher in the mix treatment, showing a significant difference in RCD. The northern slope had a higher RGR and significant growth rate. This suggests that the growth improvement effect may depend on the soil moisturizer treatment method. The aspect or treatment method affectsthe drying conditions of the soil, which in turn affects its moisture content or nutrient dynamics. The present research results can be used to establish soil moisturizer treatment standards that are suitable for growth purposes. In addition, this study demonstrates that biochar treatment can be considered as an effective alternative to boost biomass and facilitate early restoration of forest fire-damaged areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6534-6541
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• 2013

The aim of this study was to develop a fiber-reinforced asphalt mixture that was designed to do the following: 1) address fatigue cracks, which is a major source of damage; and 2) increase the rutting resistance. This study reports the effects of the aggregate mixture design that incorporates a dumbbell-shaped fiber. An experiment was carried out to measure the unit weights and unit weight ratios between the mixture that was compacted and the one that was not. A method to substitute a specific aggregate mixture with the dumbbell-shaped fiber was confirmed using the volume concept according to the Bailey method. The results showed that the weight of the PCS aggregate mixture that need to be replaced was 11.88g when a 0.3% reinforcing fiber was added to the 1950g mixture.

• KIEAE Journal
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• v.11 no.5
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• pp.69-77
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• 2011

In order to solve social exclusion and segregation phenomenon and to realize social integration, the necessity of social combination and consensus has been presented and existing conception about the public lease apartment confronts a turning point due to the diversification of apartment supply system. With this social background, Eunpyeong New Town Project implemented by Seoul Metropolitan Government is the first example that supplied diverse apartments for social integration. Survey was made upon the residents aged 20 and over and living in combination apartments, lease apartments and common apartments for private ownership in the Enpyeong New Town Apartment Complex in section 1 area, and the survey sheets filled up by the respondents were collected by personal visits or by using specified gathering spots. Summary of study results is as follows: Firstly, regarding the combination method, respondents preferred the irregular combination of lease apartment units and common apartment units in the same apartment building at the top, analyzing by survey groups marked that residents of common apartment with initial ownership responded not to choose combination apartment complex or combination apartment in future. Secondly, the living consciousness with neighbors revealed that respondents were generally satisfied without difference between the residents of lease apartment and common apartment. As the demand and policies for diverse lease apartments are increasing recently, Eunpyeong New Town Project aimed for positive social integration and consensus will be evaluated as model case for social combination apartment in future. And it is necessary to introduce the policies that consider the differences in consciousness and interest of the residents among the lease apartments and common apartments.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.62-70
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• 2006

As buildings are changing variously from the side of use, efficiency and size, the construction qualities are more importantly recognized. Supervision system was enacted in the Residential Building Law in 1990 and responsibility supervision system in the Construction Engineering Management Law in 1994, respectively. However, recently revised supervision system in 2003 has some limitations: the present problems of appointing supervisor, disposing the supervisors, supervisor's works. Therefore, the aim of this study is to improve the present supervision system for mix-use residential building. By implementing the proposed revised supervision system, it will be able to expect quality improvement, confidence of the owner and the user, development of construction technology, and increase international competitiveness of supervision company.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.5
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• pp.640-650
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• 1999

As an optimal quality of the restorations, there should be a least amount of seating discrepancy between the casting and abutment teeth. However, high viscosity of the cementing medium and its resulting thickness may prevent complete seating of the restoration. The use of die spacing material provides adequate internal relief for the cementing medium. The purpose of this study is to compare the thickness of three commonly used die spacing materials. Materials and Methods: Stone plates were fabricated and divided into 12 sections to be painted with die spacers. Tru-Fit, Whip-Mix and Belle do St. Claire die spacer which are commonly used in dental practice were tested in this study. Each die spacers were painted layer by layer according to the manufacturer's recommendation. The average thickness of each die spacers were measured with light microscope(${\times}100$) and compared between them. Results and Conclusions. A silver-colored Tru-Fit die spacer has the lowest value of thickness without statistical significance comparing with a gold-colored Tru-Fit die spacer and a gray layer of Whip-Mix die spacer has the highest value of thickness without any statistical significance comparing with Belle de St. Claire die spacer. Three and four layers of Tru-Fit die spacer and two layers of Whip-Mix and Belle de St. Claire die spacers seem to be in the acceptable range of thickness of 25 to $45{\mu}m$ for optimal seating of the restorations. The standard experimental design and method should be fur thor evaluated for more consistent and objective results.