• 제목/요약/키워드: weathering test

검색결과 246건 처리시간 0.022초

염분의 결정화 현상이 석재 내구성에 끼치는 영향 (Effects of salt crystallization on stone durability)

  • 김성수
    • 자원환경지질
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    • 제32권2호
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    • pp.203-208
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    • 1999
  • The main objective of this study is to suggest a new assessment method of the influence of weathering due to salt crystallization on the engineering property of rock. For this purpose, various sources of salt and salt crystallization were investigated, and artificially accelerated weathering tests were carried out. In natural envionment, weathering rate is very slow and weathering process involves complex mechanisms. Therefore artificial weathering test is essential for systematic analysis. Arificial weathering test is defined as test which controls weathering rate and agents by controlling arificial environmental condition. In this study, salt crystallization test was selected among various artificial weathering test methods, for its important role in weathering. Change of various stone properties were detexted. The change of physical properties by salt crystallization were observed as follows : 72% in Brazilian tensile strength and 72% in Slake durability. These results explain the importance of salt crystallization in the mechanical behaviour and properties of stone.

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소나무재의 촉진열화실험에 따른 재색변화에 대한 연구 (Study on the Color Changing of Pine by Accelerated Weathering Test)

  • 김광철
    • 한국가구학회지
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    • 제23권2호
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    • pp.152-162
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    • 2012
  • The color changing of the wood surface was tested by accelerated weathering test that can simulate the outdoor condition with short period. In early parts of accelerated weathering test, weight and volume of specimen all were increased due to the moisture evaporation by its high temperature and illumination level, but weight and volume of specimen all were decreased from middle parts to last. However, significancy showed between control group and accelerated weathering test group in terms of weight and volume. According to the results of color-difference meter, in the early parts of the accelerated weathering test lightness, redness and yellowness all showed a clear increasing or decreasing trend. However, after three weeks all values were almost never change. Until the early parts of the test, lightness was decreased and there was not a considerable change after three weeks in the test. Redness showed a some change in early parts of the test, but this also showed not great change after middle parts of the test as like lightness. Yellowness also showed same pattern. These results could be verified through the visual inspection. As like weight and volume, significancy showed between control group and accelerated weathering test group in terms of color-difference test. In all accelerated weathering test group, color-differences of after test was lower than that of before test. To correctly analyze this cause, more additional research will be need on each of temperature, humidity and illumination factors.

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건축용 우레탄 실란트의 옥외폭로시험평가 방법 개발 (Outdoor Weathering Test for used Construction Urethane Type Sealants)

  • 이상국;배기선
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.69-70
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    • 2017
  • In Korea, silicone type sealant is widely used for construction site. Before the silicone type, urethane type is one of the main type sealants. However, the weathering property is less than the silicone type, the urethane type is replace by the silicone one. Still the urethane type is used for the inside of the buildings for the perimeter of the window. The silicone type sealants are better in weathering property than those of the urethane type sealants. Except the weathering property urethane type sealant has its own advantage like movement property, low cost and so forth. There are many research results for the outdoor weathering of the sealants, but in Korea there are no results for the outdoor weathering for construction sealants. This research is focused on the outdoor weathering of the urethane sealants, how to measure the degradation, and compare the products which used in Korea. The outdoor weathering test is usually time consuming, thus we designed specialized device for accelerating the result.

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Fall cone test의 함수비를 이용한 잔적토의 풍화도 측정 (Estimation of Degree of Weathering in Residual Soil Using Water Content from Fall Cone Test Result)

  • 손영환;장병욱;김성필
    • 한국지반공학회논문집
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    • 제23권12호
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    • pp.13-23
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    • 2007
  • 풍화토는 암석으로부터 풍화되어 그 산물로 나타난다. 또한, 풍화정도에 따라 연암, 풍화암, 잔적토에 이르기까지 그 산물은 다양하다. 일반적으로 풍화정도의 결정은 화학적 방법이나 표준관입시험의 N-value를 이용한다. 그러나 이러한 방법은 약간의 단점을 가지고 있으며, 이에 본 연구에서는 교란시료와 물리적인 방법인 Fall cone test를 이용하여 풍화정도를 결정할 수 있는 방법을 제시하였다. Fall cone test 결과, 동일한 지역에서 풍화정도의 차이를 확인할 수 있었으며, 관입량에 따른 화학적풍화지수(CWI)와 함수비의 관계는 하나의 방정식으로 표현할 수 있었다.

풍화에 따른 퇴적암의 강도 변화 (The Variation of Sedimentary Rock Strength due to Weathering)

  • 배우석;이봉직;오세욱;이종규
    • 한국안전학회지
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    • 제18권1호
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    • pp.89-93
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    • 2003
  • The failure of rock slopes were influenced by weathering, which causes change in the shear strength. The weathering is also directly related to slaking and swelling characteristics. In the paper, the core of diameter loom was obtained by digging on rock slope of Kong-ju in Korea and then EDX(Energy Dispersive X-ray spectrometer) analysis was carried out to verified element of chief rock-forming minerals. Uniaxial compression tests, slaking tests, and point load test are performed to study engineering characteristics of conglomerate and red shale. As a results of slaking test, slaking index of conglomerate indicate range of 85.11-99.58 and shale indicate 58.37-99.23. Therefore, it is recognized that the resistance of shale to weathering decreases in shallow depth and it greatly influences the strength of rock. The result of uniaxial compression test and Point load test show that the strength of sedimentary such as conglomerate and red shale has an influence on both weathering and saturation.

화강 풍화암의 지반특성 및 풍화도 평가에 대한 사례 연구 (A Case Study on Geotechnical Properties and Weathering Degree of Weathered Granite Rock)

  • 이승환;유병수;정충기
    • 한국지반공학회논문집
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    • 제33권12호
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    • pp.127-139
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    • 2017
  • 고양 지역의 화강 풍화암 지층을 대상으로 시추조사 및 다양한 현장 시추공 시험(프레셔미터시험, 공내전단시험, Downhole test, Suspension PS 검층, 밀도검층)을 수행하였고, 채취한 풍화암 코어시료에 대한 X선 형광분석을 실시하여 풍화도를 평가하였다. 현장 시추공 시험 결과로부터 변형계수, 전단강도 정수, 전단파 속도 등을 평가하였고, 심도에 따라 각 지반특성 값이 증가하는 경향을 확인하였다. X선 형광분석을 통해 산정한 화학적 풍화지수는 심도에 따라 풍화도가 감소하는 일반적인 경향을 나타냈으며, 대표적 풍화지수인 VR과 풍화암의 지반특성과의 관계를 분석하였다.

Fall Cone을 이용한 풍화도 측정(실트질 모래에 대하여) (Estimation of Weathered Degree Using Fall cone in Weathered Soil ; Silty Sand)

  • 손영환;김성필;장병욱
    • 한국농공학회논문집
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    • 제50권1호
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    • pp.61-68
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    • 2008
  • It is essential to analyze and classify the physical characteristics of weathered granite for engineering purposes. This paper is to suggest a physical method to determine the degree of weathering of weathered soils. A new classification method for determining the degree of weathering is suggested, based upon the results from laboratory tests including fall cone test. According to the proposed physical method using fall cone apparatus, the measured values of the samples from the same area show distinctive difference of weathering. The water content tends to increase with increasing the degree of weathering at the same penetration in fall cone test. And relationship between CWI and water content are expressed one equation in Hwaseong area and Ilsan area.

동결-융해 시험에 의한 화강암의 풍화 특성 연구 (Weathering Characteristics of Granite by Freeze-Thaw Cyclic Test)

  • 박연준;유광호;양광용;우익;박찬;송원경
    • 터널과지하공간
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    • 제13권3호
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    • pp.215-224
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    • 2003
  • 자연 상태에서의 물리적 풍화를 실험적으로 재현하기 위해서 동결-응해 시험을 실시하였다. 시험 과정에서 탄성파 속도, 흡수율, 무게 및 부피 변화 등의 물리적 성질을 측정하였으며, 시험 전 및 시험 종료 후에 일축압축시험을 실시하여 강도 및 탄성 계수의 변화도 조사하였다. 시료의 무게 및 부피 변화는 풍화의 진전 정도와 명확한 상관관계를 보이지 않았으나 탄성파 속도와 일축압축강도 및 탄성계수는 풍화가 진행되면서 감소함을 보였다. 시험 결과는 암반 사면의 장기적 안정성 평가에 이용될 수 있을 것으로 기대된다.

촉진열화실험에 따른 목재 부재의 재색 특성 분석 (Analysis of Surface Color Characteristics of Wood in Accelerated Weathering Test)

  • 김광철;박천영
    • 한국가구학회지
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    • 제26권3호
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    • pp.262-266
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    • 2015
  • This study was carried out to analyze the surface color change according to the weathering time. The surface color of material was one of evaluation indexes in exposure experiment. For the purpose, accelerated weathering test was performed with wood. The weathering time level was composed with 0, 500, 1000, 1500 and 2000 hours and color difference was estimated with the color difference meter. The surface color was changed to 500 hours that lightness and redness were decreased and yellowness was increased. However it did not changed after 500 hours. It means that the surface color could be the evaluation index of deterioration of the wood but it means very little after certain time.

촉진 열화 느티나무 부재의 역학적 특성 (Mechanical Properties of Zelkova Serrata Makino in Accelerated Weathering Test)

  • 김광철;박천영
    • 한국가구학회지
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    • 제26권4호
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    • pp.392-397
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    • 2015
  • This study was carried out to analyze the effects on mechanical properties of deteriorated wood member by outdoor condition. The surface color, mechanical properties and structural stability of traditional wooden structures, exposed in water and UV, could be changeable. For the purpose, accelerated weathering test based on outdoor condition was carried out. The weathering time levels were composed 0, 500, 1000, 1,500 and 2,000 hours and mechanical properties were evaluated on each specimen according to weathering time level. Bending properties were decreased on weathering but recovered after 1,000 hours. Fatigue and impact strength were decreased to 1,000 hours and did not changed since then. Abrasion resistance was minimized in 1,000 hours. This results could be utilized for effectively stability management of traditional wooden structures and members.