• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.124-127
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• 2003

Sewage sludge and clay used as raw materials in the study. Green aggregates contain different contents by dried weight of the sewage sludge, up to 80 percent is manufactured and burning conditions of soak temperature, soak time and rate of temperature increase. influence of burning condition and mixing ratio on specific gravity of burned aggregate are discussed. The appropriate burning condition to all aggregates is evaluated. Aggregates result form the thermal treatment get specific gravity under 0.8, water absorption fewer than 7.5 percent, and aggregate crushing value from 28 to 53. As the result, aggregates can be available as the lightweight aggregate for non-structural concrete.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.2
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• pp.161-168
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• 2018

This paper presents the design procedure of the suction bucket used to support a subsea manifold. The soil-suction bucket interaction numerical analysis technique was verified by comparing the present results with a reference data. In order to simulate the soil-bucket interaction analyses of a subsea manifold structure, various material data such as undrained shear strength, elastic modulus, and poisson ratio of soft clay in Gulf of Mexico were collected from reference survey. We proposed vertical and horizontal design loads based on system weights and current-induced drag forces. Under the assumption that diameter of the suction bucket was 3.0 m considering real dimension of the subsea manifold frame structures, aspect ratio was decided to be 3.0 based on reference survey. The ultimate bearing load components were determined using tangent intersection method. It was proved that the two design load components were less than ultimate bearing loads.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.170-180
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• 2000

The surface-drainage system, which consists of bio-swale and detention-infiltration Basins and carries out the function of temporary detention-infiltration of runoff, is defined as the "natural drainage system". It is an environmentally sound and economically beneficial practice to reduce run-off by retaining it in swales as much as possible and letting run-off infiltrate into the ground. In order to estimate appropriate capacity of swales, it is necessary to know how long will it take for certain depths of water to infiltrate. The ponding times, or infiltration times, of various depths and of various soil textures, could be estimated with the Green-Ampt Infiltration Model. Included soil textures are loamy sand, sandy loam, loam, silty loam, sandy clay loam and clay loam. Ponding depths are from 10cm to 100cm intervals. Newton-Raphson method is used for the solution of the Green-Ampt equation by a computer program. The computer program was written with the FORTRAN Developer 4.0 v.. Selected ponding depth is acceptable when the sum of the ponding time and the breeding time of mosquitoes is less than the tolerance period of innundation of grasses and trees.and trees.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.5
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• pp.107-115
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• 2002

This study was carried out to compare artificial soil formulated by blending calcined clay and coconut peat with perlite, then to evaluate this soil as a perlite substitute for use as an artificial planting medium. To achieve this, a determination of the physico-chemical properties and it's effect on plant growth were conducted by comparing those with large perlite grains and small grains. The results are summarized as follows: 1) The bulk density was 0.41g/㎤. This density was lower than that of field soil, but higher than that of large perlite grain(0.23g/㎤) and small grain(0.25g/㎤). The porosity, field capacity, and saturated hydraulic conductivity were 71.3%, 49.2%, and 3.8$\times$10-2cm/s, respectively. The air-permeability, water holding capacity, and drainage were better than or equal to that both large and small perlite grain. 2) It was near-neutral in reaction(pH=6.6). It had a high organic carbon content(65.8g/kg) and a low available phosphoric acid content(84.7mg/kg). It was similar to crop soil in cation exchange capacity(11.4cmol/kg). It had a low exchangeable calcium content(0.71cmol/kg), a low exchangeable magnesium content(0.68cmol/kg), a high exchangeable potassium content(2.54cmol/kg), and a high exchangeable sodium content(1.12cmol/kg). Except for the exchangeable potassium and sodium content, the chemical properties were better than or equal to both large and small grain perlite. The excessive exchangeable potassium or sodium content will inhibit plant growth. 3) In Experiment 1, the plant growth tended to be higher compared to that of large and small perlite gains. But in Experiment 2, it tended to be lower. This might be linked to the excessive exchangeable potassium or sodium content. 4) It could be considered as a renewable perlite substitute for greening of artificial soil. But, it would be necessary to leach the excessive exchangeable potassium or sodium to avoid the risk of inhibiting plant growth.

• Journal of the Korea Institute of Building Construction
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• v.19 no.5
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• pp.401-409
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• 2019

This paper aims to recycle red mud from a byproduct in the alumina industry as an alternative raw material for depleted natural resources. In order to apply red mud as a ceramic material, red mud ceramics were prepared according to mixing and temperature in a laboratory environment. Compared with KS L 4201 in terms of compression ratios and absorptions, it is found that two kinds of conditions for one type and three conditions for two types meet the standard. When red mud is used as a clay brick raw material, the substitution ratio of red mud is 10% or less, and the firing temperature is considered to be appropriate at $1200^{\circ}C$. In order to apply red mud to clay brick raw material in actual field, various samples and firing temperature should be considered in the future.

• KIEAE Journal
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• v.9 no.1
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• pp.77-83
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• 2009

In this experiment, we used different addition ratio of the pigment and straw, to improve the decorative effect of the finishing touch while finding the kinds of clay colors taking on many sophisticated images, through the comparison between the various colors and textures of the surface. (1) To test the plaster material, added were the pigment of Red, Yellow, Black, and Green by the percentages of 0.5, 1, 1.5, 2, and 2.5, respectively, followed by the analysis of the color changes of the plaster material using the Photoshop (RGB). The results showed the bigger the addition ratio of the red color is, the higher the numeral values of RGB after it dried. However the brightness after drying didn't showed a big difference depending on the addition ratio. With the addition of the yellow pigment, the color difference between after and before drying was bigger in the order of Blue, Green and Red; the brightness increasingly rose while the saturation changed little. (2) When we scratched the plaster surface with U and V shape carving knives, the U knife didn't make a clean shape digging around the clay plaster material but with smooth textures, while the V knife made a clean cut, which represents its readily use in terms of the decorative function of the clay plaster. (3) In an experiment the surface texture was tested with different lengths and additions ratio of the straw, addition of 2cm straw by 1, 2, and 3% presented the most appropriate surface of the plaster.

• Geomechanics and Engineering
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• v.7 no.2
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• pp.213-231
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• 2014

An elastoplastic model for structured clays, which is formulated based on the fact that the difference in mechanical behavior of structured and reconstituted clays is caused by the change of fabric in the post-yield deformation range, is present in this paper. This model is developed from an elastoplastic model for overconsolidated reconstituted clays, by considering that the variation in the yield surface of structured clays is similar to that of overconsolidated reconstituted clays. However, in order to describe the mechanical behavior of structured clays with precision, the model takes the bonding and parabolic strength envelope into consideration. Compared with the Cam-clay model, only two new parameters are required in the model for structured clays, which can be determined from isotropic compression and triaxial shear tests at different confining pressures. The comparison of model predictions and results of drained and undrained triaxial shear tests on four different marine clays shows that the model can capture reasonable well the strength and deformation characteristics of structured clays, including negative and positive dilatancy, strain-hardening and softening during shearing.

• Journal of Environmental Science International
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• v.30 no.1
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• pp.87-96
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• 2021

Herb has been categorized as a special plants from the beginning of human history and used in different medical systems in different cultures. This research has classified soil into 6 kinds that have diverse elements to see to which various kinds of savory(satureja hortensis) adapt well, experimenting from sowing to flowering for around 13 weeks, and also divided indoor conditions to get the result below. In conclusion, growth status of savory depending on the kinds of soil suggest that in indoor conditions the savory if planted in ⑤ bed soil compounded with saprolite and poultry manure grew better than any other condition. On the other hand, the growth status was bad in ① masato, ② clay, ④ bed soil mixed with saprolite, and ⑥ bed soil mixed with clay conditions. Though you can see the immediate effect of soil on the growth of savory, I'd like to reveal the details of how elements of savory operate in which kind of soil and outdoor conditions the goal of this research, in the next research.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.4
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• pp.720-738
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• 2015

This study examined the dynamic response of a subsea pipeline under an impact load to determine the effect of the seabed soil. A laboratory-scale soil-based pipeline impact test was carried out to investigate the pipeline deformation/strain as well as the interaction with the soil-pipeline. In addition, an impact test was simulated using the finite element technique, and the calculated strain was compared with the experimental results. During the simulation, the pipeline was described based on an elasto-plastic analysis, and the soil was modeled using the Mohr-Coulomb failure criterion. The results obtained were compared with ASME D31.8, and the differences between the analysis results and the rules were specifically investigated. Modified ASME formulae were proposed to calculate the precise structural behavior of a subsea pipeline under an impact load when considering sand- and clay-based seabed soils.

• Journal of the Korean Institute of Rural Architecture
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• v.11 no.3
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• pp.19-28
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• 2009

This research aimed at showing an improvement direction in the future by analyzing the tendency to select a rural landscape housing and the characteristics centering around the data of the landscape-authenticated housing executed in Chuncheon City from 2005 to 2008. For 4 years, 25 houses in all were authenticated by Chuncheon City after being selected as landscape housing. As the result of analyzing the authenticated 25 housing, lots of landscape houses were located in natural green areas, and small-scale houses of $99m^2$ or less in the house size were preferred. The structures introducing the nature-friendly materials such as wood, yellow earth and clay continued to increase in the house structure. And in the selection of the authenticated houses, the landscape architecture and the harmony with the surrounding environment had a big effect on the selection.