개질 아스팔트 혼합물의 변형강도 측정 연구

김광우,도영수,이기호,조문진,최선주 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

본 논문은 아스팔트 혼합물의 소성변형 저항성과 상관성이 높은 특성치를 찾고자 Kim test를 개발하여 현재 적용성 연구결과를 다루고 있다. 이 논문은 새로운 강도특성치인 변형강도(S_(D))를 개발하는 Kim, test 연구의 4단계 연구 결과이다. 13 mm 골재(편마암, 화강암)와 입도(밀입도, 갭입도) 5가지 폴리머로 제조한 8가지 바인더로 두 가지 입도에서 소성변형 저항성이 다른 32가지 혼합물을 만들었다. 슬래브(305㎜×305㎜×62㎜)공시체를 제조하여 한쪽은 Kim, test를 수행하기 위하여 18 cm정도로 잘라서 코어를 3개 채취하고 다른 한쪽은 12cm크기로 하여 반복주행시험을 실시하였다. Kim, test는 하중봉 3(0.75), 4(1.0)을 사용하였다. W/T시험으로부터 최종 침하 깊이와 동적안정도의 두 가지 소성변형 계수를 각 혼합물별로 구했다. 각 하중봉과 골재별, 입도별로 S_(D)와 소성변형 계수간의 통계적 상관관계 분석을 수행한 결과 S_(D)와 소성변형 계수와의 결정계수가 매우 높게 (R²>0.95) 나타났다. 하중봉 4(1.0)이 3(0.75)보다 다소 높은 상관성을 보였다. 향후 Kim test실험에서 하중봉 4(1.0)을 사용하고 4단계 방법을 이용한다면 소성변형 특성치인 침하깊이(DR)와 동적안정도(DS)와의 상관성이 매우 큰 시험법이 될 것이다. 또한 변형강도의 파괴 메커니즘은 콘크리트의 펀칭파괴와 유사하여 콘크리트의 전단강도 추정식을 근거로 아스팔트 콘크리트의 재료 특성에 적합한 추정식 계수 ◁ 원문 수식 참조 ▷ 를 얻었다. 이 식을 이용한다면 아스팔트 콘크리트가 견딜 수 있는 임계하중을 변형강도에 근거하여 추정할 수 있을 것이다. This study shows predictability of rut parameters of modified and unmodified asphalt concretes based on the deformation strength (S_(D)) which is calculated from the maximum load, deformation and size variables of loading head under simple static loading. This paper is the result of latest studies, phase 4 which is a part of Kim, Test studies for developing a new strength property for asphalt concrete. Two aggregates, gneiss and granite, two gradations, dense-graded, gap-graded, with maximum, size of 13mm and eight binders using different contents of five polymers (RLDPE, RHDPE, LDPE, SBS, SBR) were used to produce 32 different mixtures. A slab (305㎜×305㎜×62㎜) was cut into two pieces(18cm and 12cm width) and three 10cm cores were taken for S_(D) test from the larger piece and wheel tracking test was performed on the smaller piece. Kim test was performed using loading head 4(1.0), 3(0.75). Two rut parameters, depth of rut and dynamic stability, from the rut depth-cycle curve from a WT test were obtained for each mixture. Statistical analysis were performed for each loading head, aggregate, and gradation to find out correlation between S_(D) values and each rut parameter. The analysis results showed that S_(D) had high R² (over 0.95) on the average with rut parameters. The loading head 4(1.0) showed R² better than 3(0.75). It is concluded that S_(D) is the property that has excellent predictability for rut parameter of asphalt concretes. An equation, ◁ 원문 수식 참조 ▷ was obtained based on the equation of concrete shear load creating punching failure and current test data, because the failure mechanism of S_(D) is similar to punching failure of concrete. In the equation, P is shearing force creating punching effect, b is length of perimeter of punching area and d is depth of specimen. If this formula is used, a critical load for deformation failure will be predicted based on the S_(D).

HDPE 폐비닐 개질 아스팔트 혼합물의 강도 및 공용 특성 연구

김광우 ( Kim Kwang Woo ),이기호 ( Lee Gi Ho ),권오선 ( Kwon Oh Sun ),조문진 ( Cho Mun Jin ) 한국농공학회 2004 한국농공학회 학술대회초록집 Vol.2004 No.-

본 연구는 폐비닐 펠렛을 도로포장재료로 재활용하여 자원절약 및 아스팔트 혼합물의 품질향상을 위한 연구이다. 이를 위하여 폐비닐의 첨가량별 배합설계를 수행하여 적정 폐비닐 첨가량과 최적 아스팔트 함량으로 편마암과 화강암 2가지 골재와 폐비닐인 RHDPE의 함량을 4가지로 혼합물을 제작하여 8종류의 개질 혼합물과 2종류의 무개질 혼합물을 제작하였다. 그리고 이 공시체에 대하여 마살안정도, 간접인장강도 및 Kim test와 반복주행시험 등 실내시험을 통하여 혼합물의 특성을 분석하였다. 폐비닐 첨가량은 RHDPE가 8%일 때 안정도와 간접인장강도 모두 가장 우수한 것으로 나타났고 취성도 나타나지 않았다. RHDPE를 첨가한 혼합물에 대하여 Kim test를 수행한 결과 DR과 DS 모두 높은 상관성을 보였다. 그리고 반복주행시험에서는 RHDPE를 첨가한 혼합물이 일반 혼합물보다 우수하였다. 향후 많은 실험을 통해 RHDPE의 우수성을 입증한다면 소성변형 저항성에 우수한 재료로 이용될 수 있을 것이다. This study is a fundamental research for recycled high-density polyethylene (RHDPE) in asphalt mixture for improving roadway pavement. Mix design was conducted by RHDPE content and optimum asphalt content (OAC) was determined for dense-graded surface course mixture. Marshall stability test, indirect tensile strength (ITS) test, wheel tracking test and Kim-test were carried out to measure the characteristics of RHDPE-added asphalt concretes. From the results of this study, RHDPE in asphalt mixture is possible. It could be considered that adding too much RHDPE in asphalt mixture is not proper. The optimum content of RHDPE was appeared to be 8%. In Kim-test, Statistical analysis were performed for each loading head and aggregate to find out correlation between SD values and each rut parameter. The analysis result showed that SD had very high coefficient of determination on the average with rut parameters.

HDPE 개질 아스팔트 혼합물의 강도 및 변형특성

김광우,이기호,권오선,고태영 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

본 연구는 폐비닐 펠렛을 도로포장재료로 재활용하여 자원절약 및 아스팔트 혼합물의 품질향상을 위한 연구이다. 이를 위하여 폐비닐의 첨가량별 배합설계를 수행하여 적정 폐비닐 첨가량과 최적 아스팔트 함량으로 편마암과 화강암 2가지 골재와 폐비닐인 RHDPE의 함량을 4가지로 혼합물을 제작하여 8종류의 재질 혼합물과 2종류의 무개질 혼합물을 제작하였다. 그리고 이 공시체에 대하여 마샬안정도, 간접인장강도 및 Kim test와 반복주행시험 등 실내시험을 통하여 혼합물의 특성을 분석하였다. 폐비닐 첨가량은 RHDPE가 8%일 때 안정도와 간접인장강도 모두 가장 우수한 것으로 나타났고 취성도 나타나지 않았다. RHDPE를 첨가한 혼합물에 대하여 Kim test를 수행한 결과 DR과 DS 모두 높은 상관성을 보였다. 그리고 반복주행시험에서는 RHDPE를 첨가한 혼합물이 일반 혼합물보다 우수하였다. 향후 많은 실험을 통해 RHDPE의 우수성을 입증한다면 소성변형 저항성에 우수한 재료로 이용될 수 있을 것이다. This study is a fundamental research for recycled high-density polyethylene (RHDPE) in asphalt mixture for improving roadway pavement. Marshall mix design was conducted and optimum asphalt content(OAC) was determined for dense-graded surface course mixture by RHDPE content. Marshall stability test, indirect tensile strength (ITS) test, wheel tracking trest and Kim-test were carried out to measure the characteristics of RHDPE-added asphalt concretes. From the results of this study, RHDPE in asphalt mixture if possible. It could be considered that adding too much RHDPE in asphalt mixture is not proper. The optimum content of RHDPE was appeared to be 8%. In Kim-test, statistical analysis was performed for each loading head and aggregate to find out correlation between S_(D) values and each rut parameter. The analysis result showed that S_(D) had very high coefficient of determination with rut parameters on the average.

교육대학교에서의 교수-학습에 관한 대안적 관점

김왕근,김광명,장병기 춘천교육대학교 초등교육연구소 2001 敎育硏究 Vol.18 No.-

농업구조물의 안전진단 및 개·보수 공법 선정 시스템 개발

김종옥,고만기,최진용,김기동,윤광식,김한중 公州大學校 産業開發硏究所 1998 産業開發硏究 Vol.6 No.-

A study was conducted to develope a system for safety appraisal and repair works on agricultural structures. Location, size, type, maintenance record, structural and functional problems of agricultural structures in Yedang irrigation district were surveyed. A grahpic user interface program assisting onsite field investigation of typical agricultural structural problems such as fractures and cracks of members was developed. Typical rehabilitation methods were investigated and coded for database development.

우리나라 논 관개용 지하수 수질 특성

김진호,조광래,임수정,이경자,경기천,엄미정,김희권,김찬용,이영한,이신찬,윤순강 한국환경농학회 2003 한국환경농학회지 Vol.22 No.4

This study was carried out to evaluate the status of the groundwater quality for paddy fields irrigation in Korea. Water samples were collected at 130 sites throughout the country. Samples were collected at three seasons-April, July and October-in 2000. According to our survey, the groundwater was found to be suitable for irrigation purpose. Average EC was shown 0.286 dS/m. Nitrate-nitrogen and Cl^(-) concentration was 5.6 ㎎/L, 32.95 ㎎/L which satisfied the Korean Standards for Irrigation Water. Nitrate-nitrogen concentration in each province was shown as following orders: Jeju (11.17 ㎎/L) > Chungnam (8.16 ㎎/L) > Gyeongbuk (6.64 ㎎/L) > Gyounggi (5.91 ㎎/L) > Chungnam (4.95 ㎎/L) > Gyeongnam (3.91 mgk) > Jeonbuk (3.50 ㎎/L) > Jeonnam (3.27 ㎎/L) > Gangwon (2.91 ㎎/L). The concentration by sampling seasons were October (6.62 ㎎/L) > July (5.88 mg&) > April (4.78㎎/L). As the soil of Jeju Province is usually derived from volcanic ash soils mainly used for upland drops, it may influence the nitrate-nitrogen concentration of groundwater. The amount of rainfall also influence the water quality. But the COD_(Cr), were shown April (3.17㎎/L) > July (2.91 ㎎/L) > October (2.40 ㎎/L), it is highly related in the basal dose of organic matter fertilizers. This study demonstrated that groundwater quality was suitable for irrigation, but continuous monitoring is recommended for agricultural policy and developing OECD agricultural environment indicators.

光州川의 水質汚染에 對한 硏究

金秉煥,盧基煥,柳一光 광주보건대학 1985 論文集 Vol.10 No.-

A study on the wate pollution of Kwangju stream by the relationship between physical-chemical condition and indicator planktons distribution by water quality level was examined at 6 sampling positions during the period from Mar, 25 to Jun, 25 1984. The results were as follows; 1. pH was in the range of 6.3∼7.6. 2. The mid-stream of Kwangju stream was the more severly polluted than the other sampling positions and the average range for it was 0.3∼3.9 ppm of DO, 62∼352 ppm of BOD, 5.3∼24 ppm of T-N and 2.3∼140 ppm of T-P. 3. The plankton identification in this period showed 5 genera 6 species of Cyanophycea, 11 genera 15 species of Bacillariophyceae, 9 genera 16 species of Chlorophyceae and 6 genera 7 species of protozoa: total 31 genera 44 species. 4. In biological water analysis, upper stream(sp. 1) showed from Oligosaprobic to β-mesosaprobic but the stream in the mid-town area polysaprobic. 5. In the mid-stream (BOD 62~352 ppm) dominant species were appeared Oscillatoria tennis of Cyanophyceae and Paramecium caudatum and Euglena sp. of Protozoa. 6. We would like to propose establishing sewage plants near to the upper-stream and the down-stream of Kwangju stream.

혼화재료를 혼입한 압출 성형 경량콘크리트 패널의 기초적 특성에 관한 실험적 연구

김영진,남정민,공민호,김광기,임남기,정상진 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

The propose of this study is to discover the extrusion lightweight concrete panel mixing by admixture. The standard of water ratio 50% and weight substitution 0%, 10% by Fly-ash. When produce manufactures, there use to maintain its form weight substitution and addition among the viscosity agent each Silica-fume and Hydroxy propyl methyl cellulose. The study is basic properties and performances of extrusion lightweight concrete panels. Testing methods was specific gravity, water absorption, resistance to impact, thermal conductivity, sound insulation.

에코뮤지엄 개념에 기초한 지역문화재의 보전 및 이용현황에 관한 실태분석

김선화,문동기,박광범 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(계획계)

Recently an inhabitants participation campaign that utilize cultural inheritance to place of history education in area rescue regional quality is implemented in advanced countries. The purpose of this study is aimed to investigate the conservation present condition and utilization present condition cultural assets in chongju city, Korea. This study is grope possibility that do cultural assets being in area throught ecomuseum theory as can do function by area people's lifelong education.

액체-고체 순환유동층의 상승관에서 액상의 점도가 고체체류량 및 열전달계수에 미치는 영향

이찬기,강석환,신광식,송평섭,강용,김상돈 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.4

직경이 0.102 m이고 높이가 3.5 m인 액체-고체 순환유동층에서 액체의 점도가 고체입자의 체류량과 열전달계수에 미치는 영향을 검토하였다. 밀도가 2,500 kg/㎥인 유리구슬(d_(p)=1.0, 1.7, 2.1 또는 3.0 mm)과 CMC 용액(μ_(L)=0.96-38 mPas)을 각각 고체상과 액체상으로 사용하였다. 액체-고체 순환유동층에서 고체입자의 체류량은 액체의 유속이나 점도가 증가함에 따라 감소하였고 유동입자의 크기나 입자의 순환속도가 증가함에 따라 증가하였다. 액체-고체 순환유동층에서 열전달계수는 액체의 점도가 증가함에 따라 감소하였고 유동입자의 크기나 순환속도가 증가함에 따라 증가하였으나, 액체의 유속이 증가함에 따라서는 큰 변화가 없었다. 액체-고체 순환유동층에서 고체입자의 체류량과 열전달계수는 다음과 같이 실험변수와 무차원군에 의해 상관식으로 얻을 수 있었다. E_(S) = 0.783U^(-0.100)_(L)G^(0.164)_(S)d^(0.302)_(p)μ^(-0.036)_(L) h = 4349.3U^(0.010)_(L)G^(0.099)_(S)d^(0.151)_(p)μ^(-0.015)_(L) ◁그림삽입▷ Effects of liquid viscosity on the solid holdup and heat transfer coefficient have been investigated in the riser of a liquid-solid circulating fluidized beds, whose diameter is 0.102 m and 3.5 m in height. Glass beads (d_(p)=1.0, 1.7, 2.1 or 3.0 ㎜) whose density is 2,500 ㎏/㎥ and aqueous solutions of carboxymethy cellulose (CMC)(μ_(L)=0.96-38 mPas) have been used as the solid and liquid phase, respectively. It has been found that the solid holdup decreases with increasing liquid velocity or viscosity, but it increases with increasing solid particle size or solid circulation rate. The heat transfer coefficient decreases with increasing liquid viscosity but it increases with increasing particle size or solid circulation rate, however, it does not change considerablely with increasing liquid velocity. The solid holdup and heat transfer coefficient have been well correlated in terms of operating variables or dimensionless groups as fellow: ◁수식원문참조▷