• Title/Summary/Keyword: ready-to-use

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Effect of fine fillers from industrial waste and various chemical additives on the placeability of self-compacting concrete

  • Utepov, Yelbek;Akhmetov, Daniyar;Akhmatshaeva, Ilnur
    • Computers and Concrete
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    • v.25 no.1
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    • pp.59-65
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    • 2020
  • The premise for the study reflected in this article is the need to dispose of industrial waste, which is increasingly being used in the construction materials industry. Also, dynamically developing building industry demands attention of scientists and a direction of their works on improvement of the technology of carrying out construction works. Thus, the article is devoted to studying the influence of various chemical additives and fine fillers (industrial wastes) available in Kazakhstan on self-compacting concrete (SCC) mixtures and its rheological, physical, and technical properties. According to the studies, revealed the most efficient type of fine-dispersed filler and the most optimal type of chemical additive to enable obtaining a high-quality SCC mixture based on local raw materials. As a result, the use of microsilica in comparison with other industrial wastes resulted in a conglomerate with high compressive strength of SCC at early terms of curing. In terms of economic efficiency and quality improvement, the results of study are of practical value for the manufacturers of ready-mixed concrete operating in Kazakhstan.

An Experimental Study on the Engineering Properties of Middle Fluidity Concrete using the Fly-ash and Portland Blast-Furnace Slag Cement (플라이 애쉬 및 고로시멘트를 사용한 중유동콘크리트의 공학적 특성에 관한 실험적 연구)

  • 윤종기;나철성;송민섭;김재환;장종호;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.44-47
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    • 2003
  • High flowing concrete has not spread whole in the normal concrete structure, because it requires special quality control technique. Recently owing to the lack of natural resources and reinforcement of environmental standard, the construction cost of cement is rapidly increased. Also ready mixed concrete industry has gone through various economical difficulty as the manufacture cost of concrete is increased. So, the purpose of this study is to evaluate the qualities of middle fluidity concrete using the fly-ash and portland blast-furnace slag cement in order to decrease the amount of cement and resolve the problem of the quality control of high flowing concrete and the manufacture cost. The results of this study show that it reduces the amount of addition of superplasticizer and develope properties of concrete to the use the fly-ash and portland blast-furnace slag cement.

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A comparative Study of the Housework Related to Daily Meals in Korea and Japanese Families (한일 양국의 식생활관련 가사노동의 수행 실태에 관한 연구)

  • 이기영;김외숙;윤미림
    • Journal of Family Resource Management and Policy Review
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    • v.2 no.2
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    • pp.105-118
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    • 1998
  • The purpose of this study was to compare the performance mode of housework related to daily meals. The data for 214 Korean couples living in Seoul and 136 Japanese Couples in Tokyo were collected using structured questionnaires and time diaries. The performance mode of housework were analyzed according to the employment status of wives. The results were as follows; Generally Koreans and Japanese wives had similar patterns in the time use of meals preparation and dish washing. In both nations Husbands seldom participated meals preparation, wives did most part of the work. But Japanese husbands of full-time employed wives spent more time on meals preparation than their Korean counterparts did. Korean wives received more help from other family members and paid labor, on the contrary Japanese wives purchased more ready-made goods for food preparation.

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Effect of Fine Content of the Fine Aggregate is on the Quality of the Cement Mortar (잔골재의 미립분 함유량이 시멘트 모르타르의 품질에 미치는 영향)

  • Kim, Min-Sang;Park, Yong-Jun;Jo, Man-Ki;Kim, Young-Tae;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.121-122
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    • 2016
  • Recently in the domestic construction industry, source depletion has resulted in instances of ready-mixed concrete companies using river sand or crushed sand with high fine particle content. But the use of such low-quality fine aggregate is known to cause concrete quality to decline and have negative effects. So this study analyzed how much of an impact changes in fine particle content have on cement mortar's engineering characteristics. As a result, the flow rate and air quantity, which are characteristics of unhardened mortar, were shown to decrease as fine particle content increased, and compression strength, a characteristic of light mortar, was shown to subtly increase as fine particle content decreased.

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A Study on Application of Ready Mixed Concrete of ECO Lightweight Aggregate using Sewage Sludge (하수 슬러지를 이용한 친환경인공경량골재콘크리트의 레미콘 적용 연구)

  • Seo Chi ho;Ji Seok Won;Lee Seung Yeun;Jee Suk Won;Lee Jae Sam;Lee Jin Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.109-112
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    • 2005
  • As civilization progresses amount of sewage sludge continues to increase from a sewage disposal plant with a huge expenditure of water resources. So It is necessary to reduce the high costs of sewage disposal and the pollution of the environment and also a unit cost of artificial lightweight aggregate by continual recycling. The purpose of this study is to put artificial lightweight aggregate concrete to practical use by using sewage sludge and clay

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Effects of climate condition on concrete slab with modified-latex (외기조건이 개질된 라텍스 혼입콘크리트 슬래브 표면에 미치는 영향)

  • Cha, Hun;Kim, Dae-Geon;Choi, Sang-Hwan;Moon, Kyeong-Sik
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.7-8
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    • 2014
  • Latex-modified concrete using ready mix concrete (R-LMC) was developed for application of building construction project (specifically, the rooftop of a parking garage unable to use heavy equipments for bridge deck overlay) due to three major outstanding properties of R-LMC; bond strength, resistance of cracks at early age, and resistance of freezing and thawing. However, R-LMC at the placement stage is required to be sufficiently cured because R-LMC is very sensitive to rate of evaporation of surface moisture. This study focused on effects of different curing methods and climate condition on cracks on the surface of hardened R-LMC considering the chart of rate of evaporation of surface moisture from concrete provided by American Concrete Institute in manual for placement of latex modified concrete.

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Acceptable Values of Kappa for Comparison of Two Groups

  • Seigel Daniel G.;Podgor Marvin J.;Remaley Nancy A.
    • 대한예방의학회:학술대회논문집
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    • 1994.02b
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    • pp.129-136
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    • 1994
  • A model was developed for a simple clinical trial in which graders had defined probabilities of misclassifying pathologic material to disease present or absent. The authors compared Kappa between graders, and efficiency and bias in the clinical trial in the presence of misclassification. Though related to bias and efficiency, Kappa did not predict these two statistics well. These results pertain generally to evaluation of systems for encoding medical information, and the relevance of Kappa in determining whether such systems are ready for use in comparative studies. The authors conclude that, by itself, Kappa is not informative Enough to evaluate the appropriateness of a grading scheme for comparative studies. Additional, and perhaps difficult, questions must be addressed for such evaluation.

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A PRACTICAL HUMAN RESOURCE MANAGEMENT PLAN FOR FOREIGN CONSTRUCTION WORKERS

  • Seung-Heon Han;Eui-Jae Jin;Sang-Hyuk Park
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.1216-1222
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    • 2005
  • A shortage of construction field workers has been a serious problem, both in the developed and in the developing countries. As a solution for conquering this problem, these countries import foreign laborers from nearby less-developed countries. While this contributes to lessening the labor deficiency, foreign workers are relatively inefficient in productivity and are often exposed to the cross-cultural risks due to cultural differences, communication difficulties, different work ethics and customs, etc. Despite these facts, construction firms do not well address these issues and are lagged in establishing an appropriate management strategy against it. This paper presents a practical management plan for foreign construction workers through Focus Group Interviews (FGI) and survey investigation. On this basis, this study examines the level of awareness and important managerial aspects of the issue of foreign laborers. Finally, it suggests a cross-cultural and ready-to-use practical human resource management plan for facilitating the foreign worker's productivity.

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The Effect of System Characteristic of E-learning Systems and Self-Efficacy on Learning Performance (정보기술 e-서비스품질의 이용자 지각과 이용의도에 관한 연구)

  • Kim, Yong-Beom;Lee, Mee-Jeong
    • Proceedings of the Safety Management and Science Conference
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    • 2009.04a
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    • pp.281-294
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    • 2009
  • Recently the information system introduction and the application which use the computer are increasing. The efficient operation of information system helps corporations to improve productivity, customer service and corporate competitive power. SaaS(Software as a Service), which is the developed type of outsourcing in the area of information technology, is to use standardized and packaged application by hosting from the outside of enterprise. SaaS is not developed yet as much as people's interest about that in the initial stage, but its related technology and service capacity are accumulated after repeated trial and error, and it's ready to activate the industry. In the area of information system, studies on the measurement of service quality were followed. But there is little study on service quality measurement in the field of SaaS(Software as a Service). The purpose of this study was to divides the SaaS with e-SERVQUAL and it consider the relationship with the perceived recognition and the usage intention. According to this, variables of traditional research were rejected because SaaS is not developed yet in Korea. But information had a strong effect on perceived recognition. Therefore, business related with in SaaS must have provided a correct information about various applications.

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A Study on the Effect of evaluation characteristics of Information Technology e-Service Quality on usage perception and intention (정보기술 e-서비스품질의 평가특성이 이용자 지각과 이용의도에 관한 연구)

  • Kim, Yong-Beom
    • Journal of the Korea Safety Management & Science
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    • v.11 no.3
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    • pp.95-103
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    • 2009
  • Recently the information system introduction and the application which use the computer are increasing. The efficient operation of information system helps corporations to improve productivity, customer service and corporate competitive power. SaaS(Software as a Service), which is the developed type of outsourcing in the area of information technology, is to use standardized and packaged application by hosting from the outside of enterprise. SaaS is not developed yet as much as people's interest about that in the initial stage, but its related technology and service capacity are accumulated after repeated trial and error, and it's ready to activate the industry. In the area of information system, studies on the measurement of service quality were followed. But there is little study on service quality measurement in the field of SaaS(Software as a Service). The purpose of this study was to divides the SaaS with e-SERVQUAL and it consider the relationship with the perceived recognition and the usage intention. According to this, variables of traditional research were rejected because SaaS is not developed yet in Korea. But information had a strong effect on perceived recognition. Therefore, business related with in SaaS must have provided a correct information about various applications.