• Title/Summary/Keyword: concrete materials

Search Result 4,028, Processing Time 0.047 seconds

A study of Hwang Jae Nae Kyung(黃帝內經)'s O Haeng Kui Ryoo(五行歸類) (황제내경(黃帝內徑)의 오행귀류(五行歸類)에 관한 고찰(考察))

  • Kim, Hun Kwan;Hong, Won Sik
    • Journal of Korean Medical classics
    • /
    • v.9
    • /
    • pp.654-699
    • /
    • 1996
  • By studying Hwang Jae Nae Kyung(黃帝內經)'s O Haeng Kui Ryoo(五行歸類) in view of Chinese-Ancient-Thought like Chun In Hap Il Lon(天人合一論). Um Yang O Hang Lon(陰陽五行論). The theory of the month's age the conclusion is reached as follows 1. Chun In Hap Il Lon(天人合一論) means naturally men and nature consist of one energy to counteract each other and then developed to be concidered that the change of men and nature is same one;that is the basic thought of Hwang Jae Nae Kyung(黃帝內經) 2. Um Yang(陰陽) stands originally for the bright and the dark by sunrise or sunset. Ju Yuk Gye Sa Jun(周易繫辭傳) ahs considered Um Yang(陰陽) as the energy to explain changes of nature. O Haeng(五行) meaned originally five necessary materials or stuffs for living and then Chu Yun(鄒衍) has considered the difference between five powers in the nature through the combination with thought of O Haeng(五行). Hwang Jae Nae Kyung(黃帝內經) writes in the viewpoint of Um Yang O Haeng(陰陽五行) to analyze the changes of men and nature effectively. 3. O Haeng Kui Ryoo(五行歸類) is originated from Sang Su Hong Bum(尙書洪範) and its concrete examples are found in Kwan Ja(管子) and Yu SSi Chun Chu(呂氏春秋). O Haeng Kui Ryoo(五行歸類) in Hwang Jae Nae Kyung(黃帝內經) is widly affected by Kwan Ja O Haeng(管子五行) and adopts the opinion of Kum Mun Kyung Hak(今文經學) because of the background of times and medical physiology. 4. Hwang Jae Nae Kyung(黃帝內經) thinks that O Haeng(五行) means Mok(木) is the energy of being born, Hwa(火) growing-up, Kum(金) accumulating, Su(水) concluding, To(土) devoloping. O Haeng Kui Ryoo(五行歸類) in the heaven and the earth is classified by the property of O Haeng(五行). 5. O Haeng Kui Ryoo(五行歸類) in men can be explained so rationally with the property of O Haeng(五行) and the thery of an organism studied.

  • PDF

Analysis on Anisotropy of Void Distribution and Stiffness of Lightweight Aggregate using CT Images (CT 이미지를 활용한 경량 골재의 방향에 따른 공극 분포 및 강성도의 이방성 분석)

  • Chung, Sang-Yeop;Han, Tong-Seok;Yun, Tae Sup;Youm, Kwang Soo;Jeon, Hyun-Gyu;Kang, Dong Hun
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.25 no.3
    • /
    • pp.227-235
    • /
    • 2012
  • The void distribution in concrete materials strongly affects its material properties. Therefore, the identification of spatial distribution of void is important to understand and estimate material behavior. To examine and quantify the void distribution inside lightweight aggregates, CT(computed tomography) image is used. 3D lightweight aggregate images are generated by stacking of cross-sectional images from CT. Spatial distribution of void of aggregate along the direction is visualized on the sphere using probability distribution function. Stiffness of lightweight aggregate for the directions is also examined. It is confirmed that direction-based probability distribution and stiffness from CT images are effective in characterizing void distributions of aggregates.

How To Implement Environmental Issues in Mathematics Curriculum And Textbooks (환경 교육과 수학 교육의 접점을 탐색)

  • 박경미;김정여
    • Hwankyungkyoyuk
    • /
    • v.12 no.1
    • /
    • pp.172-188
    • /
    • 1999
  • Mathematics has been usually recognized as value-neutral and anti-ideological subject, and as a result, it has not dealt with environmental problems clearly. Also, it is not easy to find any environment-related contents in the 7th mathematics curriculum. However, because mathematics is also precious human products and essence, in any ways there is a need to reflect the social issues in the mathematics subject which speak for human mental activities. If this need is admitted to change the mathematics contents to the direction of social issues, environmental problems can stand out and be dealt in the mathematics education. Among the 6 domains in the 7th mathematics curriculum, the environmental problems can be dealt with in the domains of ‘numbers and operation’, ‘letters and formulas’, ‘regularity and function’, ‘chances and statistics’, ‘measurement’ except in the domain of ‘diagrams’. Also, the '문장제들' which takes up a considerable part of mathematics textbooks needs the authentic situation, and thus it will be possible to take environmental situations as mathematical materials. Furthermore, one of the 7th mathematics curriculum is that it suggested further study in each level of each domain, the representative pattern of which is the application of the mathemantics contents to the daily life. With this kind of mathematics further study contents, environmental problems can provide a variety of contents for the further study. From this viewpoint, it can be expected that the contents of environmental education will be increased in the mathematics subject. Under the recognition that the mathematics subject cannot be an exception in considering environmental problems, this study has studied some concrete plans and examples for how the mathematics textbooks based on the 7th educational curriculum can deal with environmental Problems.

  • PDF

Material Characteristics of Traditional Bricks used in the Royal Tomb of King Muryeong, Gongju, Korea and Its Reproduction Bricks (무령왕릉에 사용된 전돌과 재현 전돌의 재료학적 특성)

  • Kwon, Yang Hee;Hong, Sung Gul
    • Journal of Conservation Science
    • /
    • v.30 no.3
    • /
    • pp.287-298
    • /
    • 2014
  • This study investigates the material properties of the traditional bricks used in the royal tomb of King Muryeong. Compressive strengths, thermal conductivities, absorptance and the rate of residual moisture are measured by non-destructive experiments. Compressive strength of the traditional bricks is estimated by using the ultrasonic wave velocity and the absorptance. Based on the experimental results, the predicted compressive strengths using the ultrasonic wave velocity are unsuitable for the traditional bricks due to the rough surface and thickness variation of the specimens. The strengths using the absorptance are more suitable than those using the velocity because the predicted average strengths (28.69 MPa ~ 33.19 MPa) are close to building materials like normal strength concrete. In addition, the methods using the absorptance are not influenced by surface and thickness conditions of the specimens. The average thermal conductivities of the bricks measured by using Mathis TCi are close to those of soils (1.58 W/mK). The absorptance and the rate of residual moisture of the bricks are 1.6 % ~ 15 %, 0 % ~ 0.7 %, respectively.

Cyclic Responses of Steel Reinforced ECC Column under Reversed Cyclic Loading Conditions (철근 보강된 ECC 기둥의 반복하중에 대한 이력거동)

  • Hyun, Jung-Hwan;Shim, Young-Heung;Bang, Jin-Wook;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.19 no.4
    • /
    • pp.75-82
    • /
    • 2015
  • In this study, experimental research was carried out to evaluate steel reinforced ECC (Engineered Cementitious Composites) column, which exhibits excellent crack control property and highly ductile behavior. Ordinary portland cement and high volume fly ash were used as binding materials in the mixture proportions for the purpose of achieving a high level of multiple cracking property with the tightly controlled crack width. To compare with the cyclic behavior of steel reinforced ECC column specimen, a conventional reinforced concrete column was prepared and tested under reversed cyclic loading condition. Based on the cyclic load test, ECC column exhibited higher cyclic behavior, compared to the conventional RC column, in terms of load carrying capacity and energy dissipation capacity.

Flexural Performance Characteristics of High Performance Slurry Infiltrated Fiber Reinforced Cementitious Composite according to Fiber Volume Fraction (섬유혼입률에 따른 고성능 슬러리 충전 강섬유보강 시멘트 복합체의 휨성능 특성)

  • Kim, Seung-Won;Cho, Hyun-Myung;Lee, Hak-Yong;Park, Cheol-Woo
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.19 no.4
    • /
    • pp.109-115
    • /
    • 2015
  • High performance fiber reinforced cementitious composite (HPFRCC) can provide high fracture energy absorption as well as high strength with high fiber volume fraction. The increased fracture energy helps resisting high frequency loadings, such as earthquake, impact or blast. This study investigates the flexural performance of slurry infiltrated fiber concrete (SIFCON), one of the important HPFRCC, with respect to varying fiber volume fraction. The maximum fiber volume fraction was 8.0 % and reduced to 6.0% by 0.5% and the maximum volume fraction is obtained by packing fibers with simple tapping by hands. The used fiber was a steel fiber with the length 30 mm and the diameter of 0.5 mm. The flexural strengths were 48.7 MPa at 8.0 % and 22.8 MPa at 6.0 %. The measured flexural strength is much higher compared to other cememtitious composite materials but decreased proportional to the fractions. This result implies that for SIFCON considered herein the reduced amount of steel fibers may affect its flexural performance in a negatively way. The flexural toughness, an index to represent the fracture energy absorption, also decreased with the reduced fiber amount.

Status and Response Strategies of Carbon Labeling in Landscape Architecture (조경분야 탄소성적표지제도 적용실태 및 대응전략)

  • Kim, Jeong-Ho;Yoon, Yong-Han
    • Journal of Environmental Science International
    • /
    • v.24 no.6
    • /
    • pp.709-720
    • /
    • 2015
  • After analyzing the actual acquisition status of carbon labeling by year and by product for the past four years, as well as its certification in the construction-related sectors of greenhouse gas emission, this study attempted to present the problems and coping strategies upon issuing the carbon labeling certification in the landscape architecture. During the period of this analysis, the carbon labelings were acquired by 134 enterprises, 267 workplaces, and 735 products, while the percentage of acquisition was highest in the regular non-durable goods(49%), followed by energy-consuming durable goods(26%), regular production goods (19%), regular durable goods(3%), and service(3%). Furthermore, the acquisition certifications in construction sectors, were highest in the various pipes/panel(8 cases), followed by concrete(6 cases), gypsum board(4 cases), and landscape architecture materials(2 cases). The landscape architecture only had two cases in the acquisition certification for the first time in 2012, which accounted for 0.27% of the entire certification products, due to the uncertainty in the process, the lack of professionalism, and the lack of comprehension. However, the study conducted on the coping strategies for carbon labeling in the landscape architecture revealed the following: (1) regular reporting system management through the division of labor in the head office and factories, (2) the building of objective DB through the adoption of data management programs such as SAP, (3) continuous promotion and vitalization of the incentive system, (4) the adoption of mandatory or preferential application system in landscaping projects, management, and bidding, (5) enhancement of elasticity in deliberation of certification by recruiting experts in the landscape architecture sectors, and (6) provision of incentives for the cooperative firms acquiring the certification and support for their participation.

Student Teachers and Beginning Teachers' Understandings of Scientific Inquiry

  • Flick, Larry;Morrell, Patricia-D.;Wainwright, Camille;Park, Young-Shin
    • Journal of the Korean earth science society
    • /
    • v.25 no.3
    • /
    • pp.160-175
    • /
    • 2004
  • This study examined the knowledge and practices of scientific inquiry displayed by three student teachers and two beginning teachers at secondary levels. Observations using the instrument of OTOP designed by the research team of OCEPT (Oregon Collaborative for Excellent in the Preparation of Teachers) generalized similar teaching strategies of scientific inquiry between student and beginning teachers, such as using group work for students' first hand experience, using concrete materials for experimentation or visual tools for demonstration, using questions for factual knowledge mainly without opportunities to understand how scientific knowledge is constructed. Those scientific inquiry activities were very confirmative ones to follow the steps without opportunities of understanding nature of science or nature of scientific inquiry. However, all participants in this study hold knowledge of scientific inquiry envisioned by the National Science Education Standards [NSES] (NRC, 1996), where students identify their hypothesis, use critical and logical thinking, and consider alternative explanations through argumentation as well as experimentation. An inconsistent relationship between participating teachers knowledge and practices about scientific inquiry resulted from their lack of pedagogy skills of implementing it in the classroom. Providing opportunities for these teachers to reflect on their beliefs and practices about scientific inquiry was recommended for the future study. Furthermore, increasing college faculty interest in new teaching approaches for upgrading the content knowledge of student teachers and beginning teachers was recommended as a solution, since those teachers showed evidence of influence by college faculties at universities in their pedagogy skills.

Durability of Mortar Matrix Replaced with Recycled Fine Aggregates (순환골재(循環骨材)를 혼입(混入)한 모르타르 경화체(硬化體)의 내구(耐久) 특성(特性))

  • Kim, Jong-Pil;Lee, Seung-Tae;Jung, Ho-Seop;Park, Kwang-Pil;Kim, Seong-Soo
    • Resources Recycling
    • /
    • v.16 no.6
    • /
    • pp.20-27
    • /
    • 2007
  • This paper presents a detailed experimental study on the durability properties of mortar matrix made with two kind of recycled fine aggregates(RAA, RAB) and five replacement levels (0, 25, 40, 75 and 100) of the recycled fine aggregates as a partial replacement of natural fine aggregate (NA). The durability properties of mortar matrix was evaluated using compressive strength, chloride ion ingress, sulfate attack and carbonation. The test results indicated that the water absorption and Adhered mortar of the recycled fine aggregate was a major factor controlling durability properties. Hereafter, when using built recycled fine aggregate is expected, appropriate removal Adhered mortar and reasonable replacement ratio of recycled fine aggregates was 25% weight of cement are advised to apply to the concrete materials.

Effect of Pretreatment of Mine Tailings on the Performance of Controlled Low Strength Materials (저강도 고유동 충전재의 성능에 미치는 광미 전처리의 영향)

  • Tafesse, Million;Kim, Hyeong-Ki
    • Resources Recycling
    • /
    • v.26 no.3
    • /
    • pp.32-38
    • /
    • 2017
  • For the massive recycling of mine tailings, which are an inorganic by-product of mining process, in the field of civil engineering, pretreatments to extract heavy metals are required. This study focuses on the use of pre-treated tailings as substitute fillers for controlled low-strength material (CLSM). As a comparative study, untreated tailing, microwave-treated tailing and magnetic separated with microwaved tailing were used in this study. Cement contents amounting to 10%, 20% and 30% by the weight of the tailings were designed. Both compressive strength and flowability for all types of mixture were satisfied with the requirements of the American Concrete Institute (ACI) Committee 229, i.e., 0.3-8.3 MPa of compressive strength and longer than 200 mm flowability. Furthermore, all mixtures showed settlements less than 1% by volume of the mix.