• 한국세라믹학회지
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• 제45권8호
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• pp.443-452
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• 2008

Shrinkage crack is a major concern for cement materials, especially for flat structures such as Korean On-Dol floor system, flooring for garages, and wall. One of the methods to reduce the adverse effects of shrinkage cracking is to reinforce cement materials with shot randomly distributed fibers. The efficiency of inorganic fibrous material to arresting cracks in cementitious composites was studied. Cement materials reinforced with five different qualities of inorganic fibrous material were tested. Contents of inorganic fibrous material were 1.0 kg, 1.5 kg, 2.0 kg, 2.5 kg, 3.0 kg by weight of cement mortar and C : S types of cement mortar were 1:3 and 1:4. W/C were 60% and 80%. Cement mortar of inorganic fibrous material reinforcement showed an ability to reduce the crack width and crack length significantly as compared to unreinforced cement mortar. $40%{\sim}60%$ drop in shrinkage crack of 1:4 cement mortar with 1.5 kg over was observed.

• 한국구조물진단유지관리공학회 논문집
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• 제4권1호
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• pp.131-138
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• 2000

In this study, physical and engineering properties of ordinary portland cement and microcement were investigated to verify reinforcing effect of underpinning of open caisson foundation by using microcement grouting. Laboratory injection tests such as infiltration and injection in case of seepage for the stream bed soil at ${\bigcirc}{\bigcirc}$ Great Bridge in Seoul were carried out. Field injection tests to reinforce open caisson foundation at ${\bigcirc}{\bigcirc}$ Great Bridge were performed and the ability of application by microcement grouting was evaluated. From the test results, physical and engineering properties of microcement are better than those of ordinary portland cement. Also, the ability of infiltration and solidity in case of seepage is better than that of ordinary portland cement. Therefore, it is concluded that microcement is an excellent material to reinforce open caisson foundation of the existing bridge structure under the water and can be used as underpinning material of general foundations.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.81-84
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• 2002

An approach for predicting the effective thermal conductivities of fiber-reinforce composite has been developed based on a thermal-electrical analogy. The unit cell of the composite laminate is divided into regular volume elements and the material properties have been given to each element. By constructing the series-parallel thermal resistance network, the thermal conductivities of composite both in-plane and out-of-plane direction have been predicted. Graphite/Epoxy composite is used for a balanced plain-weave composite laminate. By comparing the predicted results and the previous works, good agreement has been found.

• Advanced Composite Materials
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• 제16권4호
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• pp.349-360
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• 2007

Recently, natural fiber reinforced composite is attracting attention and considered as an environmentally friendly material. Usually cellulosic fibers are used to reinforce the composites, but some protein fibers such as silk and wool serve the same purpose. In this paper, we proposed a method of producing artistic composite from artistic fabric by using silk fiber reinforced biodegradable plastic, which is designated as 'silk composite', for reinforcement. In order to expand applications of the silk composite, we performed the compression molding of decorative laminates with woody material, which was selected as a core material, and examined the properties of molded decorative laminates with various content of the silk composite. Since plywood and medium-density fiberboard (MDF) are widely used for decorative laminates, we selected them as core materials. As a result, flexible decorative laminates with high flexural strength were obtained by compounding the silk composite with wood materials.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.249-250
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• 2018

To control the floor noise generated in the apartment building, a method of reinforcing the floor at the floor is applied. However, since existing buildings are difficult to reinforce upper generations, the ceilings of lower generations should be reinforced. The purpose of this study is to analyze the reduction effect by measuring the impact noise after reinforcing the floor soundproofing material on the ceiling of the existing building. In order to ensure the economical efficiency and flame retardancy of the products used as building interior materials, the existing polyurethane foam was impregnated with mineral to prepare test specimens and attached to the concrete slab surface. As a result, it was shown that heavy impact sound can reduce 2dB~5dB and light impact sound can reduce 4~8dB.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.475-478
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• 1999

A numerical tool for predicting the behavior of reinforced concrete structures under uniaxial loads is proposed. Concrete is considered as quasi-brittle material, and for a reinforcing bar, an elastic-perfectly plastic constitutive relationship is adopted. In this study, the behavior of reinforced concrete according to the interface properties between the concrete and steel is analyzed. Comparisons between the numerical predictions and the experimental results show good agreements in the load-deflection behaviors and ultimate loads of reinforced concrete structures.

• 가족자원경영과 정책
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• 제15권3호
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• pp.23-42
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• 2011

This study proposes a plan for the residents to have a capacity to build a family-friendly community on their own. As there is not a family-friendly community related program developed for "Resident's Capacity Reinforcement", three programs closely related with family-friendly community program were analyzed instead. Analysis showed that first, the community spirit must be emphasized to maintain the characteristics of family care with social support. Second, educational contents must reflect resident's capacity elements that are necessary for participating in the family friendly community building stages. Third, there is a necessity for systematization of education courses into beginner, intermediate, and specialty course given education is continued. Fourth, there is a necessity for the curriculum that may be used for the family friendly community building to foster human and material resource management ability. Therefore, framework for the educational contents suggests X-axis and Y-axis presented by person-business and morphogenic-morphostatic as referred to Ulrich(1997),s human resource model. However, this study has limitations because educational program of 'livable community building' are analyzed for the plan to reinforce capacity to build family-friendly community. There is a necessity for continuing to improve the program by in depth interview or social survey with residents and leader in community.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.352-361
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• 2006

The grouting method is widely used in construction to reduce permeability and reinforce the ground. If the cement and grout material are not mixed well in the injection tip equipment, an opposite flow and Interception state of the chemical grouting can occur. McG method installs a special grouting device to allow better mixing of the grouting material and prevent backward flow. The block of nozzle also diversify powder rate of cement. YSS that lowers $Na_2O$ and thereby increases durability is developed by gel-forming reaction material. In this study, the seepage state and unconfined compressive strength of the injection material using the special injection tip equipment is tested. The results of laboratory and field tests clearly demonstrate that the strength increases and permeability decreases using the McG method.

• 한국지반신소재학회논문집
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• 제8권2호
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• pp.11-20
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• 2009

본 연구는 국내의 초연약지반에 적용 가능한 표층보강재를 이용한 연약지반 표층처리공법을 정립시키기 위한 기초적 연구로서 표층처리공법 지지력 산정방법을 제안하는 것을 목적으로 하고 있다. 이를 위하여 직포, 지오그리드, 강봉(대나무 대채재료)을 이용한 보강재의 단부 구속조건을 완전구속, 부분구속(3종류)으로 한 21 종류의 실내모형실험을 수행하였다. 또한 실험결과를 이용해 보강재의 강성도가 지지력효과에 미치는 영향을 고려한 지지력 산정방법을 제안하였다.

• Journal of the Korean Wood Science and Technology
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• 제11권3호
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• pp.31-38
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• 1983

파티클보드의 단점중(短點中) 하나인 저(低)휨강도(彈度)를 개선(改善)하고 건축재료(建築材料)로서 개발(開發)하기 위한 목적(目的)으로, 본(本) 실험(實驗)에서는 톱밥보드를 프라스틱 강(網)과 철강(鐵網)으로 보강(補强)시켜 보드의 물리적(物理的), 기계적(機械的) 성질(性質)을 개선(改善)하고자 하였다. 실험결과(實驗結果), 밀도(密度)에서는 철강(鐵網)을 3장 구성(構成)시킨 보드가 가장 높은 값을 나타내었고, 휨 강도에서도 밀도(密度)가 가장 높았던, 철망을 3장 구성(構成)시킨 보드가 가장 높은 값을 보였다. 고지(古紙)를 섞어서 만든 보드도 다른 보드와 비슷한 강도(强度)를 보여 고지혼용(古紙混用)보도의 가능성(可能性)을 나타냈다. 철강(鐵網)을 구성(構成)시킨 보드는 정하중(靜荷重)에 의(依)해 영구변형(永久變型)이 발생(發生)되어도 쉽게 파괴되지 않는 현상(現象)을 보였다. 보강(補强)된 보드와 합판(合板)과의 강도적(强度的) 성질(性質)을 비교(比較)해 본 결과(結果), 보강(補强)된 보드보다 합판(合板)이 훨씬 높은 수준(水準)을 보였다.