• 콘크리트학회지
• /
• 제7권2호
• /
• pp.136-145
• /
• 1995

본 연구는 천연 굵은 골재 50%를 재생골재로 대치시켜 제조한 재생콘크리트를 일반 구조물에 사용할 수 있도록 성능을 향상시키기 위한 연구의 일환으로 수행되었다. 쇄석골재 사용시의 배합설계 방법으로 콘크리트를 제조하였고 일반적인 수중양생으로 공시체를 야생하였다. 재생콘크리트의 성능향상을 목적으로 유동화제와 플라이애쉬를 첨가하였다. 압축강도 등 각종 강도와 파괴인성 등을 측정하여 이를 일반콘크리트와 비교한 결과 재생콘크리트는 강도와 탄성계수가 낮고 변형율이 크며 파괴인성도 낮았다. 그러나 유동화제의 사용으로 물-시멘트비를 35%까지 낮추므로써 슬럼프 $16{\pm}2$cm에서 일반 구조물에 소요 압축강도보다 높은$225kg/cm^2$이상의 압축강도를 얻었다. 하지만 재생콘크리트를 일반 구조물에 사용을 위해서는 탄성계수와 변형율에 대한 향상이 필요하다. 또한 플라이애쉬의 사용은 장기 강도 증진 효과를 보이는 반면 강도 저하를 유발했다.

• Structural Engineering and Mechanics
• /
• 제64권2호
• /
• pp.243-257
• /
• 2017

Investigating the properties and durability of high-strength concrete exposed to sulfuric acid attack for the purpose of its application in structures exposed to this acid is of outmost importance. In this research, the resistance and durability of high-strength concrete containing macro-polymeric or steel fibers together with the pozzolans of silica fume or nano-silica against sulfuric acid attack are explored. To accomplish this goal, in total, 108 high-strength concrete specimens were made with 9 different mix designs containing macro-polymeric and steel fibers at the volume fractions of 0.5, 0.75, and 1.0%, as well as the pozzolans of silica fume and nano-silica with the replacement levels of 10 and 2%, respectively. After placing the specimens inside a 5% sulfuric acid solution in the periods of 7, 21, and 63 days of immersion, the effect of adding the fibers and pozzolans on the compressive properties, ultrasonic pulse velocity (UPV), and weight loss of high-strength concrete was investigated and the respective results were compared with those of the reference specimens. The obtained results suggest the dependency of the resistance and durability loss of high-strength concrete against sulfuric acid attack to the properties of fibers as well as their fraction in concrete volume. Moreover, compared with using nano-silica, using silica fume in the fibrous concrete mix leads to more durable specimens against sulfuric acid attack. Finally, an optimum solution for the design parameters where the crushing load of high-strength fibrous concrete is maximized was found using response surface method (RSM).

• 한국실내디자인학회논문집
• /
• 제6호
• /
• pp.45-52
• /
• 1995

The presentation of the method by which the furniture and the architecture can be unified in one category, and the study and the verification on the mutual relation in the shape and the function are having been consistently made till the late twenties. The change of the social structure such as increasing the unit dwelling space with the small scale comes to need the efficiency in using space and the open dwelling space by the systematic spa-cial formation. Therefore, the understanding of the mean-ing and the characteristics of system furnitures as the design method which can meet such needs will be made here in this study. The application of the systematic consideration as the method of interior design means the formation of the firm image on the spacial environment through the mix-ture and link of the heterogeneous factors, the organic connection of each surface, the establishment of the natu-ral relation by linking the heterogeneous materials mutu-ally. and the easiness of the entire plan in the end. This study aims at analyzing and studying the typical charac-teristics by understanding the historical background and methodical principle which enabled the appearance of this kind of thought, and the adapted cases of the wood and metal material system furniture. There may be difference between the structural sub-stance and formative consideration. Transformative furni-ture which consists of the factors is the concept for the encrease of the multi purpose value by mixing the unit cabinets. One system can be separated horizontally, verti-cally, and to the drawers, and it gives us the disengage-ment from the artificial environment, since all the heights and width can be transformed as per each situa-tion of the space. The factors which can not be found in the other existing furniture are as follows. 1. disengagement from the artificial environment. 2. establishing the new productiosn trend as freed from the customers' fashion trend. 3. presenting the producing condition which leads the exact technology. 4. flexibility of the furniture which enables the reduction and enlargement in each situation.

• 한국지반신소재학회논문집
• /
• 제14권1호
• /
• pp.33-41
• /
• 2015

본 연구에서는 관중혼합처리공법 개발을 위해 혼합토의 공학적 특성 평가에 관한 실내실험(유동성, 단위중량, 일축압축강도 및 블리딩 시험)을 수행하였다. 실험 결과 흐름 및 블리딩 특성은 함수비에 비례하여 증가하는 것으로 나타났다. 단위중량과 일축압축강도는 함수비 증가에 따라 감소하는 것으로 나타났다. 각 주행 장비별 접지압과 혼합토의 지지력을 비교한 결과 벨트 컨베이어, 백호우, 도저 등의 장비가 즉시 진입 가능한 것으로 검토되었다. 결과적으로 고화재를 사용한 관중혼합처리공법에서 적용 가능한 함수비 영역은 80~200%로 평가되었다. 또한, 본 연구 결과로부터 설계 차트를 개발하여 제시하였다.

• 한국도로학회논문집
• /
• 제7권3호
• /
• pp.63-69
• /
• 2005

콘크리트 포장의 품질관리 항목 중에서 압축 강도는 매우 중요한 인자로 여겨져 왔다. 압축 강도 값을 얻기 위해 현장에서 코아를 채취하여 이를 품질관리의 기준으로 사용하였다. 그렇지만, 코아를 채취하는 것은 많은 인력과 시간을 필요로 하며 실제로 현장의 품질관리를 정확히 추정하는데 많은 어려움이 있다. 또한 포장의 설계 방법도 탄성계수에 근거한 역학적-경험적 방법이 도입되고 있다. 이러한 현장의 품질관리 문제점을 해결하고, 포장설계와의 연계를 위해 비파괴 실험방법이 도입되고 있다. 다양한 비파괴 실험 방법 중에서 이론적으로 탄성계수를 추정할 수 있는 방법은 Wave Propagation방법이므로 본 연구에서는 Wave Propagation 방법을 도입하였다. 본 연구에서는 현장의 품질관리를 수행하는 방법 중의 일환으로 실내에서 제작한시편의 압축 강도와 비파괴 방법으로 얻은 탄성 계수와의 상관성을 검토하였으며, 비파괴 방법으로 얻은 탄성 계수로부터 압축 강도를 추정 할 때 배합별 특성에 대한 분석을 실시하였다. 비파괴 실험에서 구한 탄성계수와 압축강도와의 상관성은 매우 우수한 것으로 판명되었으며, 골재의 종류별로 상관성이 서로 상이하게 나타남을 알 수 있었다.

• 한국생활과학회지
• /
• 제13권1호
• /
• pp.159-171
• /
• 2004

The purpose of this study was to compare the characteristic of Chanel style between modern and postmodern period. The documentary research method was used for this study. The modem period was limited from around 1920 through 1939 and the postmodern period from 1990 through present for this research. The results were summarized as follows: The characteristics of clothing style in modem period were 1) the preference of slim & straight body figure as ideal one and slim & straight clothing silhouette, 2) the high fashion image for the elite by simple & basic design, 3) the emphasis on the harmony by the unity, 4) the tendency of eliminating ornaments on clothing, 5) the discontinuation of traditional way of dress code & style, and 6) the modern style. The characteristics of clothing style in postmodern period were 1) the emphasis on erotic aspects of female body and sexy design, 2) the popularization of high fashion and certain social group's fashion, 3) the tendency of harmony by mix-match, 4) the preference of ornaments in clothing, 5) the preference of retro-fashion, and 6) the continuation of modem style.

• Computers and Concrete
• /
• 제29권 5호
• /
• pp.347-360
• /
• 2022

Fiber-reinforced cementitious composites (FRCC) have emerged as a response to the calls for strong, ductile and sustainable concrete mixes. FRCC has shown outstanding mechanical properties and ductility where special fibres are used in the mixes to give it the strength and the ability to exhibit strain hardening. With the possibility of designing the FRCC mixes to include sustainable constituents and by-products materials such as fly ash, FRCC started to emerge as a green alternative as well. To be able to design mixes that achieve these conflicting properties in concrete, there is a need to understand the composition effect on FRCC and optimize these compositions. Therefore, this paper aims to investigate the influence of FRCC compositions on the properties of fresh and hardened of FRCC and then to optimize these mix compositions using factorial design approach. Three factors, water-to-binder ratio (w/b), mineral admixtures (total of fly ash and metakaolin by cement content (MAR)), and metakaolin content (MK), were investigated to determine their effects on the properties of fresh and hardened FRCC. The results show the importance of combining both FA and MK in obtaining a satisfactory fresh and mechanical properties of FRCC. Models were suggested to elucidate the role of the studied factors and a method for optimization was proposed.

• 한국의류학회지
• /
• 제33권4호
• /
• pp.644-654
• /
• 2009

The purpose of this study is to analyze the characteristics of current fashion illustrations within the framework of Multi-space method. Multi-space means being piled up one moment & space on others, and being amassed in a scene. This method is related with Dadaism, Surrealism and Postmodernism, and also influences on the current fashion illustration. In this study, the types of Multi-space method could be classified into 4 types; Repetitive Time Mixture in Multi-space, Juxtaposed Time Mixture in Multi-space, Reiterated Space Mixture in Multi-space, Projected Space Mixture in Multi-space. The characteristics of Multi-space were analyzed and the results are as followed. The distinctive methods for Time Mixture in Multi-space are repetition and juxtaposition in a scene. Time Mixture in Multi-space can make the nonlinear narration and unreal illusory space in fashion illustrations more effectively. Reiterated Space Mixture in Multi-space can be related with the heterogeneous, surrealistic illusions in current fashion illustrations. Projected Space Mixture in Multi-space can be characterized into inter-penetration. It can derive spectators to mix the projected & transparent images in a scene for their own imaginary stories. The final imagination can be made differently according to the personal experiences of spectators.

• Computers and Concrete
• /
• 제32권2호
• /
• pp.185-206
• /
• 2023

This article aimed to explore the optimization of mineral admixtures and retarding admixture for high-performance concrete. In essence, fresh concrete can be regarded as a mixture in which both coarse and fine aggregates are suspended in a cement-based matrix paste. Based on this view, the test procedure was divided into three progressive stages of binder paste, mortar, and concrete to explore their rheological behavior and mechanical properties respectively. At each stage, there were four experimental control factors, and each factor had three levels. In order to reduce the workload of the experiment, the Taguchi method with an L9(3⁴) orthogonal array and four controllable three-level factors was adopted. The test results show that the use of the Taguchi method effectively optimized the composition of high-performance concrete. The slump of the prepared concrete was above 18 cm, and the slump flow was above 50 cm, indicating that it had good workability. On the other hand, the 28-day compressive strength of the hardened concretes was between 31.3-59.8 MPa. Furthermore, the analysis of variance (ANOVA) results showed that the most significant factor affecting the initial setting time of the fresh concretes was the retarder dosage, and its contribution percentage was 62.66%. On the other hand, the ANOVA results show that the most significant factor affecting the 28-day compressive strength of the hardened concretes was the water to binder ratio, and its contribution percentage was 79.05%.

• 디지털융복합연구
• /
• 제20권1호
• /
• pp.265-275
• /
• 2022

본 연구의 목적은 최근 여성 패션 컬렉션에 나타난 밀리터리 룩의 전환적 디자인 발상 사례를 분석하여 유형화하고 특성을 도출하는 것이다. 연구 방법은 밀리터리 룩에 관한 이론적 고찰과 패션 컬렉션 사례 분석의 순서로 진행하였다. 연구 결과는 사례 분석을 통해 총 6개의 전환적 디자인 발상 유형으로 분류되었다. 디자인의 구조 변화로 탈중심 유형, 확장과 축소의 유형, 소재 전체 변화, 혹은 일부 소재의 전환, 마지막으로 스타일링에 해당하는 이질적 조화와 유기적 결합에 따른 유형이다. 분류된 유형을 분석한 결과 총 3개의 특성이 도출되었는데, 첫째 구조적 요소의 재구성, 둘째 믹스매치의 매터리얼 확장, 셋째 스타일링의 감성적 융합이다. 뉴 밀리터리 룩의 전환적 발상 유형 연구를 통해 창의적인 디자인 발전의 원동력이 되며, 패션디자인 전반에 걸친 시대적 현황과 변화를 읽을 수 있는 기초 연구가 되기를 바란다.