• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.154-154
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• 2011

최근 세계 각지에서 발생하는 대규모 터널 화재사고는 많은 사상자를 동반하고 이에 따른 경제적, 사회적 손실 또한 방대하게 진행되는 실정이다. 터널 구조물의 화재 특성상 외부에 쉽게 노출되지 않기 때문에 화재 발생 시 화재에 노출된 표층이 박리되거나 비산해서 단면결손이 생기는 폭렬 현상(explosive spalling)이 발생하게 된다. 이러한 폭렬 현상은 붕괴와 같은 대형 참사로 이어질 가능성이 크다. 따라서 본 연구에서는 터널 내 화재 발생 시 콘크리트 구조물의 폭렬에 의한 붕괴를 예방하기 위하여 이액형 상온경화 실리콘 고무와 인체에 무해한 친환경 첨가제인 펄라이트를 일정한 혼합비(5wt%, 10wt%, 15wt%, 20wt%)로 혼합하여 고성능 난연 복합체를 제조하고, 열적 특성과 난연 특성을 연구를 진행하였다. 열적 특성에 관한 시험으로 TGA를 측정하였으며, 난연 특성에 관한 시험으로는 화염 시험, 내화로 시험, 탄화로 시험을 진행하였다. 우선 TGA 시험은 $20^{\circ}C/min$ 승온 속도로 $800^{\circ}C$까지 실험을 하였고, 화염 시험은 제작한 시편과 gas torch($1200^{\circ}C$)의 화염 거리를 약 10cm로 하여 약 1시간 동안 시험을 하였다. 내화로 시험은 내화로 장치를 이용하여 RABT curve(5분만에 $1200^{\circ}C$도달 후 한 시간 동안 유지 후 냉각, 총 시험 시간 180분) 조건을 만족하는 환경에서 제작한 시편을 콘크리트에 부착하여 콘크리트의 내부온도를 측정하였다. 탄화로 시험은 탄화로 장치를 이용하여 $2^{\circ}C/min$ 승온속도로 $900^{\circ}C$까지 실험을 하여 외부 형태 변화를 관찰하였다. 각각의 시험 결과 TGA 열분해 결과 순수한 실리콘 고무보다 난연제인 펄라이트를 첨가했을 때 더 높은 온도에서 초기 분해 거동을 보였으며, 최종 잔류량은 80%를 보였고, 5 wt%의 펄라이트가 혼합된 시편의 최종 잔류량이 높은 것으로 보아 열분해에 가장 강한 조성임을 알 수 있었다. 화염 시험 결과 펄라이트가 혼합된 모든 시편에서 $300^{\circ}C$가 넘지 않은 결과를 보였다. 이는 제조된 복합체가 화염에 직접적으로 장시간 노출이 되어도 안전하다는 것을 알 수 있다. 내화로 및 탄화로 시험 결과 펄라이트가 15wt%와 20wt%가 첨가된 시편들보다 5wt%와 10wt% 첨가된 시편들이 고온에서 안정하다는 것을 보였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2A
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• pp.129-136
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• 2011

Recently studies on functional concrete with a photocatalytic material such as $TiO_2$ have actively been carried out in order to remove air pollutants. The absorbtion of $TiO_2$ from those studies is applied by it being directly mixed into concrete or by suspension coated on the surface. When it comes to the effectiveness, the former process is less than that of the latter compared with the $TiO_2$ use. As a result, the direct coating of $TiO_2$ on materials' surface is more used for effectiveness. The Surface spread of it needs to have a more than $400^{\circ}C$ heat treat done to stimulate the activation and adhesion of photocatalysis. Heat treat consequently leads hydration products in concrete to be dehydrated and shrunk and is the cause of cracking. The study produces $TiO_2$ used Sol-gel method which enables it to be coated with a low temperature treat, applies it to pearlite using Lightweight Aggregate Concrete fixed with a low temperature treat and evaluates the spread performance of it. In addition to this, the size of pearlite is divided into two types: One is 2.5 mm to 5.0 mm and the other is more than 5.0 mm for the benefit of finding out the removal characteristics of $CH_3CHO$ whether they are affected by pearlite size, mixing method and ratio with $TiO_2$ and elapsed time. The result of this experiment shows that although $TiO_2$ produced by Sol-gel method is treated with 120 temperature, it maintains a high spread rate on the XRF(X ray Florescence) quantitative analysis which ranks $TiO_2$ 38 percent, $SiO_2$ 29 percent and CaO 18 percent. In the size of perlite from 2.5 mm to 5.0 mm, the removal characteristic of $CH_3CHO$ from a low temperature heated Lightweight concrete appears 20 percent higher when $TiO_2$ with Sol-gel method is spreaded on the 7 percent of surface. In other words, the removal rate is 94 percent compared with the 72 percent where $TiO_2$ is mixed in 10 percent surface. In more than 5.0 mm sized perlite, the removal rate of $CH_3CHO$, when $TiO_2$ is mixed with 10 percent, is 69 percent, which is similar with that of the previous case. It suggests that the size of pearlite has little effects on the removal rate of $CH_3CHO$. In terms of Elapsed time, the removal characteristic seems apparent at the early stage, where the average removal rate for the first 10 hours takes up 84 percent compared with that of 20 hours.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.59-70
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• 2010

More than 10 different cases of airline overrun accidents happened annually home and abroad in recent years. So the government put the guidelines to protect that kinds of accidents, which is named 'Runway End Safety Area'. However, the great part of airports are far from the standards, because most of the airports have been built before the guidelines. Moreover, in many cases natural obstacles, ambiance, and local area developments obstruct the extension of the runway to meet the criteria. For these reasons, the Federal Aviation Administration (FAA) recommends that the aviation fields construct 'Aircraft Rapid Arresting System(ARAS)' at the end of the runway. Many airdromes have been constructing the system and some airports have already completed the construction. In this research, our team performed a basic study about low strength perlite concrete to provide the proper material with 'ARAS'. As a result, the unit weight of the low strength perlite concrete was $4.5{\sim}6.4kN/m^3$ and uniaxial compressive strength was measured in the range of $400{\sim}1,470kN/m^2$. In addition, we tested penetration compressive strength by using CBR tester, and we observed that the strength was increased after around 60% of penetration rate. Also, 40% of penetration rate was measured through the penetration test with dump trucks.

• Land and Housing Review
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• v.15 no.3
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• pp.189-198
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• 2024

This study analyzes the thermal performance of insulating concrete based on material combinations aimed at carbon reduction. The study compares the thermal and structural properties of insulating concrete enhanced with perlite and EPS (Expanded Polystyrene) beads to conventional concrete, with a focus on the impact of insulation properties on thermal conductivity. The results indicate that the content of EPS beads is critical to the insulating performance, and increased moisture absorption significantly reduces the energy efficiency of the insulating concrete. These findings provide valuable insights for the design and application of insulating concrete to enhance energy efficiency and reduce carbon emissions. This study offers guidance for further developing insulating concrete as a carbon-reducing building material.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.77-82
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• 2013

The construction of LNG storage tanks has been increased due to the expansion of LNG demand. LNG tanks which consist of an inner cylindrical 9%Ni metal tank and reinforced concrete, are insulated with perlite powder and resilient blanket for absorbing the perlite pressure in insulation annulus between two inner and outer tanks. This study tries to find out the design specifications and characteristics for blanket thickness and design pressure. The results show that the design basis for the blanket thickness should be approximately 30% to 40% of annulus width and the design pressure be applied below 2,200~2,700Pa with blanket thickness.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.653-660
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• 2008

The purpose of this study is to analyze the optimal mix design of the sound absorption material that is made from perlite and various binder systems for noise barrier wall. The polymer cement slurry which is made from two types of polymer dispersions, and silicone type inorganic material are used as binder. The test specimens are prepared with various polymer cement ratios, binder ratios, and tested for strengths, freezing and thawing and sound absorption performance by the tube and the reverberation room methods. From the test results, the difference of sound absorption coefficient by the tube method is a little recognized, however, noise reduction coefficient (NRC) of test specimens bound by the polymer cement slurry is in the ranges of 0.48 to 0.51. They are a little higher than those bound by cement only, and are lower values than recommended value of 0.7 by the Ministry of Environment. However, the sound absorption coefficient of test specimens at low frequency range of 250 to 500 Hz by reverberation room method shows very high values as 0.84 to 1.00, and 0.57 to 0.77 at the high frequency. The test specimens with polymer cement slurry binder have a good balance between performance and cost, and have proper properties in strengths, freezing and thawing resistance as sound absorption material for noise barrier wall. It is apparent that the good sound absorption material can be produced according to the optimum mix design that is recommended from this study.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.605-608
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• 2006

The purpose of this research is to develop the fireproofing mortar through the improved fireproofing properties. Therefore, after manufactured the mortor by changing the mixture rate of the perlite(PL) in three level, we investigated air content, flow value and compressive strength. As a result of this research, as the mixture rate was increased and the air content was also increased. But the flow ability and the compressive strength of the mortar were comparably decreased. Beside, we also found that there is efficiency of the lightweight by mixed PL.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.533-536
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• 2004

This study aims to manufacture and to evaluate lightweight cement composite using lightweight aggregate and expanded perlite. The expanded perlite and lightweight aggregates were mixed with cement, water, SP(superplasticizer), forming-agent and poly-propylene fiber. The specimens were cured at $20^{\circ}C$ for 24h and then at steam curing of $60^{\circ}C$, RH $100\%$ for 12h. As a result, We could make lightweight cement composite of satisfaction about ALC properties. However it is need to improve the properties of density and water absorption.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.141-147
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• 2010

Liquefied natural gas(LNG) is natural gas that has been converted temporarily to liquid form for ease of storage and transport it. Natural gas is the worlds cleanest burning fossil fuel and it has emerged as the environmentally preferred fuel of choice. In Korea, the demand of this has been increased since the first import from the Indonesia in 1986. LNG takes up about 1/600th the volume of natural gas in the gaseous state by cooling it to approximately $-162^{\circ}C(-260^{\circ}F)$. The reduction in volume therefore makes it much more cost efficient to transport and store it. Modern LNG storage tanks are typically the full containment type, which is a double-wall construction with reinforced concrete outer wall and a high-nickel steel inner tank, with extremely efficient insulation between the walls. The insulation will be installed to LNG outer tank for the isolation of cryogenic temperature. The insulation will be installed in the base slab, wall and at the roof. According to the insulation's arrangement, the different aspects of temperature transmission is shown around the outer tank. As the result of the thermal & stress analysis, by the installing cellular glass underneath the perlite concrete, the temperature difference is greatly reduced between the ambient temperature and inside of concrete wall, also reducing section force according to temperature load.

• Journal of the Korean Institute of Gas
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• v.9 no.1 s.26
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• pp.1-8
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• 2005

In this study, the FE analysis has been presented for the leakage safety of $9\%$ nickel type LNG storage tank based on the thermal resistance effects between insulation panels, comer protection and prestressed concrete(PC) structures. The FEM calculated results show that the leakage safety of fiber glass blanket, perlite powder and cellular glass insulators does not guarantee any more due to a strength failure of the insulation structure. But the corner protection and PC structure of outer tank may delay or sustain the leaked LNG of 10 days even though the inner tank and insulation structure are simultaneously failed. This means that $9\%$ nickel steel type LNG storage tank may be safe because of a high strength of the corner protection and outer tank structures.