• KIEAE Journal
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• v.11 no.4
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• pp.95-101
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• 2011

Earth has been used as a building material not only our country but also many foreign countries in the world. In foreign countries, we can often find the high-storied earthen houses which have been maintained for over several hundred years, which means the fact that earth differs in durability according to the methods of utilizing earth. So, the purpose of this study is to progress the fundamental research for utilizing earth as a wall material. Also, the another purpose of this study is to utilize the optimum micro-filler effect which adjusts the grain size of earth and the lime composite which promotes chemical combining power, and so examine whether earth material ensures its high compressive strength. This study applied both of rammed earth method and pour earth method among earth architecture methods. This study investigated compressive strength, slump, and air content according to unit binder weight. On the basis of such experimental results, this study derived the following conclusions. 1) Optimum micro-filler mixtures reduce a lot of fine particles contained in earth. If optimum micro-filler mixtures are used as aggregates, they develop lower W/B and relatively higher strength than general earth. 2) In this study, which uses optimum micro-filler earth mixtures and lime composite, rammed earth method develops 29MPa and pour earth method develops 28MPa in 28 days compressive strength. Such strengths can be utilized in building walls.

• KIEAE Journal
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• v.13 no.2
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• pp.33-38
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• 2013

Limited resources for construction material in the Mae-Hae region, a remote Northern Thailand, acted as an impetus to introduce a new way for constructing their dwellings. The new construction material brought new construction methodology, namely, using earth and bamboo which are indigenous materials, readily available for them to use. Using indigenous material at Mae-Hae region was most ecological and logical method for establishing sustainable dwellings both in terms of monetary and ecological reasons. Prior to the construction at Mae-Hae, Thailand, series of experimental tests on the strength of rammed earth were performed off site at our university and also brought soil samples from the actual job site at Mae-Hae for detailed soil analysis. Through the tests, integrity of the earth and characteristics of the soil were established to build a small senior citizen center as an example. This appropriate technology is expected to contribute to the sustainable construction at Mae-Hae.

• KIEAE Journal
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• v.10 no.5
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• pp.115-121
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• 2010

Lime was the solidifier mostly used at the fields of construction and civil works in the past. however, the development of Portland cement remarkably reduced the use of it. Recently as the concernment on circumstances gets higher, lime wined attention again as an eco-friendly material and was used at earth-using construction. This study examined the physical and chemical capacity of lime complexes with lime capacity improved, and performed fundamental study on the way to concretize by mixing it with earth. As a result, lime complex pressure strength was lower than cement pressure strength but it showed the possibility that its strength was improved by W/B control. The measurement of XRD after paste formation confirmed a compound generated by the reaction of Ca2+ion and Si, Al, and Fe from pozzolan reaction. A earth wall experiment by using lime complexes and earth showed that the higher, WB or the lower the quantity of unit combined materials, the lower the pressure strength was. The maximum pressure strength was maximum 11MPa when the quantity of unit combined materials was 450. It is because the composed earth particles had a high content of micro powder less than silt, so a lot of combination are demanded to secure fluidity. As a result of peptization experiment, after hardening, the material was not dissolved, which informed of the possibility of use as an outer subsidiary material. If the material is hardened by mold formation method, natural hardening crack appears. Cast expresses smart surface quality and enables to design for multiple purpose. The result shows the possibility of construction of low-story structures by using earth wall made of lime complexes and earth.

• Journal of the Korean earth science society
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• v.32 no.1
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• pp.140-151
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• 2011

This study is to search the problems of schoolyard teaching material developed by pre-service earth science teachers and the critical factors affecting material making. The 258 schoolyard teaching materials was collected from 54 pre-service earth science teachers (male: 18, female: 36) major in Earth Science Education in Jeonju, Korea. The schoolyard teaching materials was greatly influenced by making process type of it and the prior knowledge of pre-service earth science teachers. As schoolyard preference exploratory type rely on their prior knowledge to develop the schoolyard teaching materials, they made use of the limited concepts like fault in material making. But the concept preference exploratory type made use of concepts not accessible to majority of pre-service earth science teachers because they selected a concept from the earth science textbook first of all. The pre-service earth science teachers having wrong prior knowledge selected inappropriate resources, as well as fell into the error of concept connecting. The pre-service earth science teachers having right prior knowledge partly considered only shape of resources, but had a disregard for formation process of it in material making. Accordingly, we need to reflect richly Geological Field Trip and Solid Earth Science to curriculum for earth science teacher education. And we have to educate pre-service earth science teachers to create holistic concept on the geological subject matter knowledge, field based teaching and learning strategy, material making process.

• Journal of the Korean Solar Energy Society
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• v.26 no.4
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• pp.83-91
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• 2006

As a demand for sustainable development rises, the preference for earth house (earth construction) increases gradually. However, there are few data for predicting and evaluating the thermal environment and indoor air quality of earth house. Thus, this study aims to measure thermal properties(thermal conductivity, density and specific heat) and pollutants emission intensities(formaldehyde and volatile organic compounds) of current main earth construction materials and make a comparison between earth and cement construction materials. As results, quantitative thermal properties and pollutants emission intensities of current main earth construction materials are shown.

• KIEAE Journal
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• v.7 no.4
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• pp.3-8
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• 2007

This study is aimed to apply basic data to planning earth building through analyzing characteristics of earth building. For doing it, we investigated a research paper in advanced countries(New zealand, Australia, etc.) that has been used for earth building standards for a long time, and then we corrected inadequate standards that would apply our earth building environment. As a result, we can devide earth characteristics into three parts that are materials, plan, and maintenance and repair. First, as material selection is very important factor, a general plan is possible to change in accordance with what material is selected. These methods that made mud brick, pressed earth block, rammed earth, cob have been well used during the current 30 years in earth building. Second, the plan is composed of site select and architecture plan. In architecture plan, we should consider from foundation to eaves protection, and in site selection, consider sides of the environment and the social. Third, we should always check a periodical inspection through watchful observation because earth buildings need more time and efforts in maintaining and repairing than others.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.952-957
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• 2004

Cut and Cover Method is generally used in shallow tunnels and tunnel entrances with thin soil cover. In this type of cons0truction, backfilling is considered to be the most important process. In this process even though the backfill material is thoroughly compacted, compaction and self-weight due to vehicular vibration and pressure exerted by the soil cause the backfill material to undergo self-compression which leads to settlement. The settlement of the backfill material subjects the tunnel lining under excessive earth pressure which cause cracking and deformation. In the model test performed installation of geotextile on the sides and top of the tunnel was able to reduce the earth pressure acting on the tunnel lining.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.2
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• pp.63-73
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• 1986

The model was developed by applying the principles of Bacot and Vidal to measure the behavior of deformation of the reinforced earth wall, and various tasts were performed by using the plastic fabric filter and the galvanized steel plate as a strip. The results obtained are as follows; 1. When the reinforced earth wall is deformed by the load, the strip is completely reinforced by the backfill materials and changed to the rigid block state, under the state of failure which permits sliding only, the next theoretical equation is formed. (H/L) . tan$\theta$ [cosO-sinOtanO] =2sinO[tan($\theta$ +0) +tanO] 2.The degree of the mutual reinforcement of the backfill material and the strip depend on the physical characteristics of the each material especially the angle of shearing resistance of the backfill material is desirable over 20$^{\circ}$ and, if it is over 400, its function could be a maximum. 3.The distribution of the maximum tensile strain of the reinforcement is changing with the height of reinforced earth wall, and when the height from bottom of the reinforced earth wall is 1.85 to 3. 35m, the maximum tensile strain appears at 2m from the skin element. The maximum tensile strain is increased by the depth of the reinforced earth wall from surface, and increased with the lapse of time after construction. 4.The failure surface of the reinforced earth wall by the concrete skin was about 60$^{\circ}$and the failure behavior of the reinforced earth wall in which the fabric filter was buried was slow, and so the pore pressure could be decreased. 5.It is possible to construct the fabric retained earth wall by the plastic fabric filter only. And the reinforcing effect between the steel plate and the plastic fabric filter is not largely different. however, in the aspect of the economic durability, the plastic fabric filter is more advantageous. 6.The reinforcing action mainly depends on the width and the length of the reinforcing materials, if possible, the full width is advantageous to enlarge the contact area with backfill. but considering the economic aspect, it is neccessary to develop the method controlling the space of the strip.

• Journal of the Korean Society of Earth Science Education
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• v.9 no.3
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• pp.323-340
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• 2016

The purpose of this study is to investigate the effect of observing material on the phase change of moon considering the orbits of earth and moon for elementary school students. For this study, the material which shows the orbit of moon tilted at $5^{\circ}$ with the orbit of earth is developed. 110 6th grade students in an elementary school are sampled. They are divided into the experimental group and the control group. The lessons using the material developed in this study are implemented to the experimental group, and the lessons using the material proposed in ordinary textbook are implemented to the control group. The pre, post, delayed concept tests on the phase change of moon are administered to the students of the experimental group and the control group, and semi-structured interviews are conducted for each concept level. According to students' responses, the concept levels are divided into 'Phase recognition', 'Space viewpoint', 'Earth viewpoint', and 'No recognition'. The experimental group and the control group are homogeneous in the pre-test. The result of this study shows that the experimental group gains significantly more scores than the control group in the post and delayed tests. Also, in the post and delayed tests, more students of the experimental group are in the highest level 'Phase recognition' than the control group. Finally, students of the experimental group who were in the 'Phase recognition' and 'Space viewpoint' explain more scientifically than the students of the control group. Therefore the results of this study show that the observing material on the phase change of moon considering the orbits of earth and moon is effective.

• KIEAE Journal
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• v.10 no.2
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• pp.3-8
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• 2010

Many countermeasures are presented to make excessive earth circumstance pollution better in the earth. A lot of researches are in progress to lessen $CO_2$ among the industries exhausting it. The industries manufacturing cement are making many countermeasures. Many concernments on ECO-friendly materials, rather than cement, are increased, and researches are in progress to develop them. Lime, material mostly used before Portland cement appeared, attracts the Occident as well as the Orient. In the Occident, lime mortar was used in common, for maintaining and repairing cultural properties, too. This study is aimed at offering basic materials for the modern use of lime, ECO-friendly material. This study measured the change of intensity and weight with lime, sand, and earth, basic materials of Samhoimool. As a result, at the beginning, hydrated lime displayed its density late, but as time was gone, density was promoted continuously. In addition, density was promoted, when it was given heat at the beginning. If heat-generation reaction of quicklime and water was used, density was promoted at the beginning, but liquidity showed a drop.