• Title/Summary/Keyword: concrete material

Search Result 4,374, Processing Time 0.033 seconds

Properties of SPE-Based Cement Grout for Semi-Rigid Pavements (Sulfur Polymer Emulsion을 활용한 반강성 포장용 시멘트 주입재의 특성)

  • Lee, Byung-Jae;Lee, Jun;Hyun, Jung-Hwan;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.17 no.4
    • /
    • pp.57-65
    • /
    • 2013
  • The development of the oil refining industry has resulted in an annual 120 million tons of sulphur, which is a by-product of the desulphurization process. To exploit this abundance, the applications of sulphur must be expanded. as excellent durability of reuse of leftover sulphur which has high potential for utilization in construction materials, the study is actively in progress. Meanwhile, there has been active research on semi-rigid pavements that draw on the strengths and overcome the weaknesses of asphalt and concrete pavements. Acrylate is used to prevent cracking but involves a high cost, thus, an alternative material is required. As such, this study presents methods on the reuse of leftover sulphur and examines the engineering performance of grout containing sulfur polymer emulsion (SPE) for use in semi-rigid pavements. Our analysis shows that grout in which 30% of acrylate is replaced with SPE has superior properties in terms of time of flow and strength compared to regular grout. However, performance declined when more than 50% of acrylate was replaced by SPE, indicating that the optimum replacement level is 30%. Through SEM analysis, we found that grout with utra harding cement in this study at three hours had similar hydration properties to that of Type 1 Ordinary Portland Cement (OPC) at seven days, and maintained the properties regardless of grout containing SPE. OPC and grout with a replacement level of 30% displayed similar levels of chloride invasion resistance, whereas grout without SPE was far less resistant. Within the scope of this paper, the optimum replacement level of acrylate with SPE was found to be 30% in consideration of various properties such as time of flow, strength, and chloride invasion resistance.

Using Film Music for Second Language, Target Culture, and Ethics Education: With Reference to the OST of The Lion King (제 2언어, 문화 및 윤리 교육 자료로서의 영화 음악 활용: 라이온 킹 OST를 중심으로)

  • Kim, Hye-Jeong
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.5
    • /
    • pp.509-519
    • /
    • 2017
  • This study addresses the effective utilization of film music as learning material for language, target culture, and ethics education. Music is intertwined with language and culture, and even with ethics. This study focuses on the potential power of film music in the processes of teaching and learning in a classroom. For this purpose, five songs are selected from the soundtrack of Disney's famous animation The Lion King: "Circle of life", "I just can't wait to be king", "Be prepared", "Hakuna Matata", and "Can you feel the love tonight?", and concrete learning activities are suggested based on these. Using these five songs, gap-filling and singing-recoding tasks are proposed as listening and speaking activities respectively. Film music is also very useful in learning vocabulary, sentence structure, and grammar. Learners participate in a writing activity involving creating their own lyrics for the tunes reflecting their experiences. Next, for culture education, a teacher asks their students to discuss about, and be aware of, food culture using a specific character's song. Finally, for ethics education, a philosophy of life, natural logic, leadership qualities, and the motto Hakuna Matata("no worries") are explored and discussed through an analysis of the lyrics. The open-ended questionnaire survey is conducted. The result shows that music has a positive effect on culture and ethics education. Film music can be effective in learning a second language, target culture, and ethics.

Collaboration between Artists and Engineers: 'Experiments in Art and Technology' Group (예술가와 공학자의 협업 모델: '예술과 기술의 실험' 그룹)

  • Lim, Shan
    • The Journal of the Convergence on Culture Technology
    • /
    • v.5 no.4
    • /
    • pp.79-85
    • /
    • 2019
  • 'Experiments in Art and Technology' Group was established in the mid-20th century, and then developed the larger interdisciplinary experiments into the range of art world and its outside field. The motive power of group's activities was the collaboration between artists and engineers traversing the boundary between old different disciplinary conventions. E.A.T was officially launched in 1967 by the engineers Billy $Kl{\ddot{u}}ver$ and Fred Waldhauer and the artists Robert Raushenberg and Robert Whitman. They performed various possibility of material, technology, and engineering available to contemporary art. By reflecting the function of art and technology in society, eventually they developed the methodology of new aesthetics which had organic relationship with contemporary world. In this sense, this research have its academic significance. This paper firstly examined the socio-cultural context of emerging the E.A.T. group as a representative model for convergent practice, and verified the fact that the collaboration between artists and engineers had produced the expansion of artistic expression as well as new relationship among art, engineering, and society by considering E.A.T's various projects. Therefore, I will refer the E.A.T. group as an exemplary model for concrete method of collaboration that contemporary discourses about convergence need.

Field and remote acquisition of hyperspectral information for classification of riverside area materials (현장 및 원격 초분광 정보 계측을 통한 하천 수변공간 재료 구분)

  • Shin, Jaehyun;Seong, Hoje;Rhee, Dong Sop
    • Journal of Korea Water Resources Association
    • /
    • v.54 no.12
    • /
    • pp.1265-1274
    • /
    • 2021
  • The analysis of hyperspectral characteristics of materials near the South Han River has been conducted using riverside area measurements by drone installed hyperspectral sensors. Each spectrum reflectance of the riverside materials were compared and analyzed which were consisted of grass, concrete, soil, etc. To verify the drone installed hyperspectral measurements, a ground spectrometer was deployed for field measurements and comparisons for the materials. The comparison results showed that the riverside materials had their unique hyperspectral band characteristics, and the field measurements were similar to the remote sensing data. For the classification of the riverside area, the K-means clustering method and SVM classification method were utilized. The supervised SVM method showed accurate classification of the riverside area than the unsupervised K-means method. Using classification and clustering methods, the inherent spectral characteristic for each material was found to classify the riverside materials of hyperspectral images from drones.

A study on the Composition of the Production Rates System to Prepare Standards for Calculating the Construction Cost of PC Structure Apartments Based on Off-Site Construction (OSC) (OSC 기반 PC구조 공동주택 공사비 산정기준 마련을 위한 품셈 체계 구성에 관한 연구)

  • Lee, Hansoo;Lee, Chiho;Lee, Jeongwook;Noh, Hyunseok
    • Korean Journal of Construction Engineering and Management
    • /
    • v.22 no.6
    • /
    • pp.96-106
    • /
    • 2021
  • The PC structure based on the OSC (Off-Site Construction) is mentioned as a representative method of innovation in the construction industry that converts the existing construction environment from site-centered to factory production-transportation-site assembly. However, recent research on PC method has focused on improving the functions of subsidiary materials and improving the production system to increase productivity and institutional / policy R&D that can be universally applied to the life-cycle stage of ordering / design /construction is insufficient. In particular, the absence of standardized cost calculation standards makes it difficult to calculate and verify of objectified appropriate construction cost. So which is an obstacle to the activation of the PC method. In this study, the standards for construction costs of domestic and foreign PC method were surveyed and similar Construction Standard Production Rates were analyzed to confirm the product structure suitable for PC method. Subsequently, the construction procedures and input resources for each PC subsidiary materials were identified through on-site surveys to derive component for subsidiary materials, and the factors of change in the product according to the construction characteristics(height, weight of subsidiary material) were verified. As a result the standard product calculation system suitable for the site installation of the PC method for apartment was presented.

Study on Optimum Mixture of Industrial By-Products for Lightweight Foamed Filler Production by Mixture Experimental Design (혼합물 실험계획법에 의한 경량기포 충전재 제조를 위한 산업부산물의 최적 배합 검토)

  • Woo, Yang-Yi;Park, Keun-Bae
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.7 no.1
    • /
    • pp.37-43
    • /
    • 2019
  • This research studied production of lightweight filling production for sink hole restoration utilizing various industrial by-products(2kinds of fly ash, petro-cokes CFBC ash, blast furnace slag fine particle). For this purpose, the mixed raw material properties(compressive strength) behaviors according to the blending ratio of industrial by-products were examined by applying the experimental design method and statistical analysis was performed using the commercial program MINITAB. Compressive strengths of industrial by-products were strongly dependent on blast furnace slag powder. Compressive strength(3days aging) was 3~11MPa depending on the amount of blast furnace slag powder used. The use of CFBC fly ash was evaluated to have the least effect on compressive strength. In addition, the compressive strength and the coefficient of permeability were measured by preparing foamed concrete for the experimental batch 1 condition in the mixture experimental design. In this case, the bulk density is 0.9 to 1.0, the apparent porosity is 30 to 50%, the compressive strength(3days old) is 1 to 2MPa, and the permeability coefficient is $10^{-2}$ to $10^{-3}cm/sec$.

Evaluation Method of Healing Performance of Self-Healing Materials Based on Equivalent Crack Width (등가균열폭에 기반한 자기치유 재료의 치유성능 평가 방법)

  • Lee, Woong-Jong;Kim, Hyung-Suk;Choi, Sung;Park, Byung-Sun;Lee, Kwang-Myong
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.9 no.3
    • /
    • pp.383-388
    • /
    • 2021
  • In this study, constant head water permeability test was adopted to evaluate self-healing performance of mortars containing inorganic healing materials which consist of blast furnace slag, sodium sulfate and anhydrite. Clinker powder and sand replaced for a part of cement and fine aggregates. On constant head water permeability test for self-healing mortars, unit water flow rate of mortar specimens were measured according to crack width and healing period. As a result of evaluating the healing performance of self-healing mortar, it was confirmed that with the initial crack width of 0.3mm, the healing rate at healing period of 28 days increased by more than 30%p compared to plain mortar, greatly improving the healing performance. Furthermore, the coefficient(α) which was estimated from the relationship between crack width and unit water flow rate was used for calculating equivalent crack width. By analyzing the correlation of healing rate and equivalent crack width, the time and initial crack width attaining healing target crack width were predicted.

Education Reflection on the Concept of Hinduism Ashrama (힌두교의 아슈라마(ashrama)에 관한 교육적 고찰 : 교육이념?목적?목표와 내용 및 방법을 중심으로)

  • Woo, Beodle;Kang, Min A;Son, Dong-In;Shin, Changho
    • (The)Korea Educational Review
    • /
    • v.24 no.4
    • /
    • pp.287-311
    • /
    • 2018
  • This research identifies an educational ideal, purpose of goal intrinsic to Hindu ashrama and provide a concrete list of appropriate educational contents and methods in accordance with them. The ideal is moksa a pursuit of spiritual liberation. The goal is to be consciously aware of and practice the Dharma at each of the four stages of life, as preserved in ashrama, by completing the educational contents and methods in each stage. In the fist stage, the student stage, the goal is to learn social laws, recognize his vocation and responsibilities through studying Veda, and engage in apprenticeship with the teacher. In the second stage, the householder stage, the goal is to get married, take care of his family, and produce the kinds of service the society requires of him. In order to do so, he is expected to learn in his ordinary life the manners for family members and the ways of ancestral rituals. In the third stage, the self-disciplined stage, the goal is to retire from social responsibilities, behave in accordance with norms and rules, and set oneself free from material desire. In order to do so, he is expected to complete the eight stage of yoga and practice asceticism. In the four stage, the nirvana stage, the goal is to completely free from obsession and reaches the spiritual liberation. In order to do so, one is expected to participate in meditation and pilgrimage to the Holy Land until he reaches the final point.

The Legend's Modernization and Horror Strategy - Focus on uncanny stories concerning army (전설의 현대화와 공포의 전략 - 군대괴담을 중심으로 -)

  • Jin, Eun-Jin
    • (The)Study of the Eastern Classic
    • /
    • no.68
    • /
    • pp.439-472
    • /
    • 2017
  • The purpose of this paper is to confirm how traditional legends are changing and existing in modern times, and how they are inheriting and developing legendary values and meanings. The subject of the study is uncanny stories concerning army that is judged to be worthwhile alongside uncanny stories concerning school. The uncanny stories concerning army are urban legends that are active in the internet. It can be defined as 'a narrative story that raises fear with supernatural and strange experiences in the army'. In addition to the internet community sites, humor sites and game sites are actively handed down. Recently, ghost stories have appeared on the site, and uncanny stories concerning army are easily collected from these various sites. The uncanny stories concerning army can be divided into three types: ghost experience type, Bulgogi GP type, mystery radio type. The ghost experience type has the largest number of version, the contents are rich and varied. It does not deviate much from the traditional notion of ghosts. Bulgogi GP type has a frenzied horror from its name. It is related to actual events and raises horror. Mystery radio type is a romantic material used in movies and dramas. However, unlike movies and dramas, uncanny stories concerning army are perceived as fearsome. The uncanny stories concerning army continues to emphasize that the story is actually experienced in the title and content. It has presented concrete evidence. The emphasis on truthfulness is intended to make fear more realistic. This comes from the desire for safety. Uncanny stories concerning army focus on horror. So It tries to reveal the history and truthfulness of the story itself. As a result, the history of reality, the truth of reality, and the realistic ideology are erased. Historical and truthfulness of traditional legends has been varied in the case of uncanny stories concerning army.

Evaluation of Segment Lining Fire Resistance Based on PP Fiber Dosage and Air Contents (세그먼트 라이닝의 PP섬유 혼입량과 공기량 변화에 따른 화재저항 특성 평가)

  • Choi, Soon-Wook;Kang, Tae Sung
    • Tunnel and Underground Space
    • /
    • v.31 no.6
    • /
    • pp.469-479
    • /
    • 2021
  • As a material for preventing spalling of concrete, the effectiveness of PP fiber has already been confirmed. However, it is necessary to consider the maximum temperature that occurs during a fire, and to solve the mixing problem and the strength reduction problem that occur depending on the mixing amount. In this study, the fire resistance performance of tunnel segment linings according to the PP fiber content and air volume under the RABT fire scenario was investigated. As a result, no spalling or cross-sectional loss occurred in all test specimens, and when the PP fiber content was small, the maximum temperature was relatively high and the maximum temperature arrival time was also fast. On the other hand, no trend was found for the maximum temperature and arrival time according to the difference in air volume. In the internal temperature distribution results for the PP fiber mixing amount of 0.75, 1.0, 1.5, and 2.0 kg/m3, the results of 0.75 and 1.0 kg/m3 showed similar temperature distribution, and the results of 1.5 and 2.0 kg/m3 were similar. It was confirmed that the internal temperature distribution tends to decrease at the same depth when the amount of PP fiber mixed is large, and it was confirmed that a remarkable difference occurred from the results of 1.0 kg/m3 and 1.5 kg/m3 of PP fiber mixed amounts.