• The Journal of Engineering Geology
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• v.30 no.2
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• pp.185-198
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• 2020

High-density rapid expansion material is a method that increases the solid volume of injection materials due to hydration and foam reactions at the same time as spraying. It is an effective method for securing ground stability, restoring subsidence, and loading during construction of structures. In this regard, through the mechanical experiments of injection materials, the stability of the foundation ground of the structure and the effect of increasing the endurance using site construction were analyzed. The results of the experiment showed that the unit weight of soil decreased by 10.5% after injection of the filling material, and the allowable support for the structure was deemed safe, and the subsidence by each section after ground improvement was determined to be safe at 2.28, 1.55 and 0.46 cm, respectively, with an acceptable subsidence of less than 5 cm. After the field test, five inclinometers were installed on the top floor of the target building to measure the displacement of the X and Y axes. As a result of the measurement, no displacement related to the phenomenon of inequality or subsidence cracks of the structure was measured for about 16 months (509 days) after construction. This can be judged to be a sufficient increase in the stability of the ground after the injection of rapid expansion.

• Journal of Conservation Science
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• v.31 no.4
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• pp.351-360
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• 2015

This is the result of the study on the temporary fortifier using sublimation type Consolidate is Cyclododecane to prepare plan for reinforcement of the surface part that can be damaged during the dismantling of stone cultural heritages. To supplement the disadvantages of the existing reinforcement methods using intumescent urethane foam, Cyclododecane was diluted in solvent to reinforce the surface and inside desquamation, and after dismantling the framework, it sublimated by imposing heat of about $60^{\circ}C$. Such method can guarantee the strength needed for reinforcement of the damaged surface with outstanding reversibility of Cyclododecane being entirely sublimated. But, it shows big difference of effect according to the solvent, so it shall be diluted in petroleum ether or heated in a double boiler. Therefore, considering the working conditions at the site, it seems the most appropriate to use petroleum ether double boiler heating method for injection and filling of the desquamation part and temporary reinforcement processing with Cyclododecane diluted in petroleum ether for surface spraying.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.4
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• pp.90-100
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• 2003

본 연구는 기존 건축물 옥상녹화에 이용 가능한 저토심 옥상녹화 시스템 을 연구하고 개발하고자 수행되었다. 연구목적을 달성하기위해서 시스템의 개념적 모델이 선행 연구로부터 유추되었고 개념적 모델로부터 실험을 위한 시스템들이 제안되었다. 건축물 옥상 위에 설치된 이 시스템들에서 기린초의 생육에 대하여 인공배지 종류, 토심, 그리고 배수 형태의 효과들이 2002년 4월 3일부터 10월 18일까지 연구되었다. 인공배지 종류는 단용과 혼용이고, 토심은 5cm, l0cm,그리고 15cm이며, 배수 형태는 저수$.$배수형과 배수형으로 하였다. 여기서, 인공배지 단용은 폐유리 미분 100에 발포제를 1∼2정도 첨가하고, 착색제를 1정도 첨가한 후, 6∼8$^{\circ}C$/min로 승온하여 750∼85$0^{\circ}C$의 온도에서 발포시킨 다공질 유리를 수냉식으로 급랭하고, 분쇄기로 이송하여 l0mm이하로 분쇄하고 입도를 조절하여 얻어진 다공질 유리 파쇄물과 수피를 부피 비 6:4로 혼합하여 조성된 것이며 인공배지 혼용은 인공배 지 단용에 양토(모래 46%, 미사 40%, 점토 14%)를 부피비 5:5로 혼합하여 조성된 것이다. 피복면적, 지상부와 지하부의 생체중과 건물중, 그리고 시각적 질을 조사하였다. 각 변수들은 던칸의 다중범위 검정으로 통계처리 하였으며 처리들간의 유의수준은 5%였다. 그리고 기존 건축물 옥상에 대한 과부하의 위험을 피하기 위해서 각 시스템의 중량이 평가되었다. 그 결과를 요약하면 다음과 같다. 실험기간 중에 피복면적에 대한 배수 형태의 효과는 유의성 있는 차이를 나타내지 않았다. 인공배지 혼용의 피복면적은 인공배지 단용의 것보다 통계적으로 유의성 있게 높았다. 토심 5cm처리의 피복면적은 나머지 처리들의 피복면적보다 통계적으로 유의성 있게 낮았다. 토심 l0cm처리와 토심 15cm처리는 통계적으로 유의성이 없는 것으로 나타났다. 지상부와 뿌리의 생체중 및 건물중과 시각적 질에 대한 처리들의 효과는 피복면적에 대한 것과 유사하거나 동일하였다. 결과적으로, 기린초의 생육은 인공배지 단용보다 인공배지 혼용에서 더 높았고, 토심 10∼15cm에서 더 높았으며, 배수 형태에서는 뚜렷한 차이를 나타내지 않았다. 이 결과를 토대로, 기존 건축물 옥상에 적용 가능한 시스템의 허용하중과 기린초의 생육을 동시에 고려해볼 때, 저토심 옥상녹화 시스템 은 인공배지 종류에서는 혼용이, 토심은 10cm, 그리고 배수형태는 배수형이 적합하다고 보았다. 제안된 조건으로 조성된 시스템은 인공배지가 포장용수량상태일 때 그 중량이 약 115kg/$m^2$정도로 나타났다.

• Design & Manufacturing
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• v.9 no.3
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• pp.24-28
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• 2015

Speaking in general terms the form injection process can be described as a new process-variant of already known structural foam molding technology which roots go back to the early sixties. The most limiting factors of already know foaming processes are large cell size and the lack of uniformity of these cells as well and the inability to foam all kinds of plastic materials. In this paper, Process Study on weight change in injection rate during foaming. Experimental conditions were set as the injection speed 50,150,300 and 450 mm/s. The experiments PA, PA+GF, PP, was confirmed that the weight increase to PP+TA.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.22-23
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• 2016

This study analyzes the properties of foam according to the concentration of vegetable foaming agent that is used in traditional and mixed foaming agent of developing stage, and confirms how the foams influence foamed concrete by searching for properties of foamed concrete according to replacing ratio of vegetable foaming agent and mixed foaming agent. This is for the purpose of providing basic data for the use of foamed concrete through improvement on the problem such as unstability, falling in fluidity and the strength of existed foaming agent.

• The Korean Journal of Rheology
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• v.7 no.3
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• pp.237-249
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• 1995

폴리우레탄 미세포 포움의 가공에 대한 연구를 수행하였으며 기체 과포화 수지 내 의 핵생성율을 증진시키기 위하여 폴리올과 이소시아네이트의 혼합물에 초음파 가진을 적용 하였다. 미세포 구조는 고압에서 질소 가스로 폴리올을 과포화ㅣ키고 폴리우레탄의 두 성분 을 충돌혼합시킨 직후 초음파에 의해 기포를 생성시켜 이루어진다. 낮은 포화 압력에서 질 소에 의해 포화된수지의 핵생성율을 증가시키기위하여 초음파 가진을 적용하였다. 확산에 의해 기포의 성장이 조절된다고 가정하고 금형이 충전되는 동안에 금형 내부에서의 기포성 장기구를 이해하기 위하여 수치적인 방법으로 이론적 연구를 수행하였다. 경화 시간과 확산 경계를 고려하여 최종적인 기포의 크기를 계산하였으며 반응속도론을 고려하여 중합반응 동 안의 폴리우레탄의 점도의 변화를 예측하고 경화 시간을 결정하였다. 이론적 및 실험적으로 결정된 기포의 수를 기준으로 하여 확산 경계를 예측하였다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.58-59
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• 2018

In this study, firing experiments were carried out to confirm the foamability of the expansive shale collected from the local area. When expansive shales are subjected to high temperature heat, gas is generated inside and voids are formed. Due to this phenomenon, shale is used as a raw material for lightweight aggregate. Experiments were carried out with different plastic temperature and residence time to find the appropriate plastic temperature for this expansive shale. As a result, the higher the plastic temperature, the more the surface viscosity increased and the gas generated inside were retained. Resulting in a number of internal voids. However, even if the plastic temperature or the medium temperature is high, it is confirmed that sufficient gas is not generated when the residence time is shortened.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.21-22
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• 2018

Foamed concrete is a porous concrete that is cured by mixing bubbles into cement slurry. It is lighter than ordinary concrete and is characterized by higher insulation. Lightweight foamed concerte is mainly used as a sandwich panel in Korea, and is also used as a refractory filler in fireproof safes. Studies on lightwight foamed concrete have been carried out on strength,density and thermal conductivity. However, it is confirmed that the research on the fire resistance performance is very limited. Based on this study, fire resistance of lightweight foamed concrete using expanded polystyrene beads is investigated.

• Composites Research
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• v.27 no.6
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• pp.248-253
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• 2014

In this study, tapered double cantilever beam specimens are designed with the variable of angle to investigate the fracture property at the bonded surface of adjoint structure. These specimens are made with four kinds of models as the length of 200 mm and the slanted angles of bonded surfaces on specimens of $6^{\circ}$, $8^{\circ}$, $10^{\circ}$ and $12^{\circ}$. By investigating experiment and analysis result of these specimens, the maximum loads are happened at 120 N, 137 N, 154 N and 171 N respectively in cases of the specimens with slanted angles of $6^{\circ}$, $8^{\circ}$, $10^{\circ}$ and $12^{\circ}$. As the analysis result approach the experimental value, it is confirmed to have no much difference with the values of experiment and analysis. It is thought that the material property can be investigated effectively on shear behavior of the material composed of aluminum foam bonded with adhesive through simulation instead of experiment by applying this study method.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.166-171
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• 2014

This experimental study considers manufacturing method of the non-portland cement matrix for the light-weight building materials using blast furnace slag, paper ash, fly ash and polysilicon sludge the industrial by-product. For the experiment, we used paper ash by means of the foaming agent and alkali activator to make non-portland cement light-weight matrix. Various specimens were prepared with different types and addition ratios of the alkali activator. Then, the properties of these specimens were investigated by compressive strength test, bulk specific gravity. As a results, it was judged that experiment results of non-portland cement matrix with specific waste resources and alkali activators were useful as basic data for mixtures design and evaluation properties of lightweight non-portland cement building material.