• Title/Summary/Keyword: Mixed concrete

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A Design Research for the Practical Use of College Women′s Casual Hanbok (여대생들의 생활한복 실용화를 위한 디자인 연구)

  • 김장향
    • Journal of the Korea Fashion and Costume Design Association
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    • v.2 no.2
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    • pp.55-79
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    • 2000
  • This study is the design research for the practical use of Casual Hanbok. The conclusion of basic research for Casual Hanbok design reads as follows. Today's college women are fairly positive to the practical use of Casual Hanbok. Especially, they are strongly interested in the new design and have the active intention to wear it on actually. The concrete design of every parts of Casual Hanbok which is wanted by college women is as follows. Firstly, college women like well matched two-piece dress style in colors. And they want to decide the coloration independently than to follow the traditional coloration passively. Secondly, according to the design of jacket, sometimes they like the presence of a collar, a collar strip, a gore etc. and at other times they like absence of them. Thirdly, the side line of jacket they like and the seam line of sleeve they like is smoothly curved one and the adjusting means they like is a fancy button. Fourthly, the length of jacket they like reaches to their waist and the width of an armhole they like must be convenient for moving of arm. Fifthly, one out of two college women likes mixed spinning fabrics as material for jacket, skirt, pants. In the other hand, one out of five college women likes cotton. Sixthly, the skirt style they like is A ­line one having from two to four gathers on the waist and the length of skirt they like reaches to their ankle or calf of the leg. Seventhly, the pants style they like is the western style but the hem line of pants is the korean traditional pants style.

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Optimal location of Batcher Plant using Modified Steiner point (수정된 Steiner Point를 이용한 Batcher Plant의 최적 위치 선정)

  • Ha, Kwon-Yeol;Lee, Sang-Joong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.10
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    • pp.39-46
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    • 2015
  • REMICON(Ready Mixed Concrete), the most essential material of construction work, is produced from facility called "Batcher plant." In order to produce Remicon, Batcher Plant needs to be supplied with basic raw material such as ballast, sand, cement, admixture and water. In remicon industry, overland transport vehicles are used during the whole manufacturing process from producing to infilling at the construction site. Thus, the transportation cost sums up be to 20 percent of whole manufacturing cost and transport capacity and distance travelled have direct and major effect on manufacturing costs. This paper suggests a method to find optimal location of batcher plant using modified Steiner point, suggesting the most effective and flexible connection through among construction site, aggregate, cement and remicon producing plant. This paper also proposes reducing of transport cost at maximum 60% by calculation through optimized plant location. The modified Steiner point theory proposed in this paper also can be applied to optimal location of a $2^{ry}$ substation or MCC panel for minimizing of power loss, voltage drop, line distance and etc.

Study on CO2 Emission Reduction Effects of Using Waste Cementitious Powder as an Alternative Raw Material

  • Park, Dong-Cheon;Kwon, Eun-Hee;Hwang, Jong-Uk;Ahn, Jae-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.2
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    • pp.187-194
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    • 2014
  • With environmental regulations continuously being strengthened internationally the need to control environmental pollution and environmental load is emerging in Korea. The purpose of this study is to seek methods or using waste cementitious powder as an alternative raw material for limestone through the optimization of raw material and to quantitatively analyze the resulting reduction of $CO_2$ emission in order to contribute to solving the issue of waste, which is the biggest issue in relation to construction and global warming. The results of the study, show that waste cementitious powder can be used as an alternative raw material for limestone at OPC level, but it was also found that mixing fine aggregate cementitious powder into waste cementitious powder significantly affected the substitution rate for limestone with waste cementitious powder and the reduction of greenhouse gas. In particular, when fine aggregate cementitious powder was used at a rate of 0~20%, the substitution rate for limestone and the reduction in the rate of greenhouse gas emission was significantly reduced. It is thought that a technique to efficiently separate and discharge the fine aggregate cementitious powder mixed in waste cementitious powder needs to be developed in the future.

Shielding Thickness Calculations for Line Gamma-ray Sources in Regular Geometrical Array (일반적(一般的) 배열(配列)인 선형(線型) 감마선원(線源)의 차폐계산(遮蔽計算))

  • Lee, Chong-Chul
    • Journal of Radiation Protection and Research
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    • v.3 no.1
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    • pp.29-32
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    • 1978
  • A shielding calculation has been carried out for a storage vault of $5292(42{\times}42{\times}3)$ waste drums in which the mixed radioactive gamma-emitters are contained. The required ordinary concrete shielding thickness seems to be approximately 50cm. The results in terms of dose rate for polyenergy gammas appear to be considerably higher than those of the averaged energy gamma.

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Application of artificial neural networks for the prediction of the compressive strength of cement-based mortars

  • Asteris, Panagiotis G.;Apostolopoulou, Maria;Skentou, Athanasia D.;Moropoulou, Antonia
    • Computers and Concrete
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    • v.24 no.4
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    • pp.329-345
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    • 2019
  • Despite the extensive use of mortar materials in constructions over the last decades, there is not yet a robust quantitative method, available in the literature, which can reliably predict mortar strength based on its mix components. This limitation is due to the highly nonlinear relation between the mortar's compressive strength and the mixed components. In this paper, the application of artificial neural networks for predicting the compressive strength of mortars has been investigated. Specifically, surrogate models (such as artificial neural network models) have been used for the prediction of the compressive strength of mortars (based on experimental data available in the literature). Furthermore, compressive strength maps are presented for the first time, aiming to facilitate mortar mix design. The comparison of the derived results with the experimental findings demonstrates the ability of artificial neural networks to approximate the compressive strength of mortars in a reliable and robust manner.

Setting Analysis of Super Retarding Agent according to Curing Temperatur (양생온도 변화에 따른 초지연제의 응결지연 성능 변화 분석)

  • Hyun, Seung-Yong;Lim, Gun-Su;Han, Soo-Hwan;Kim, Jong;Han, Min-Choel;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.10-11
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    • 2020
  • This research is part of the research for unifying the mass concrete and utilizing the rate of super retarding agent. We analyzed the performance of super retarding agent under low temperature conditions. It was found that there was no deterioration in fluidity and air quality due to the change in the super retarding agent mixing rate. It was found that when super retarding agent was mixed up to 0.5 %, it was delayed for 22.3 hours at 20℃, 48.2 hours at 10℃, and 48.5 hours at 5℃. Therefore in order to ensure the performance required at the site, the super retarding agent mixing rate must be determined by fully considering the situation at the site. In addition it will be analyzed that super retarding agent performance analysis at high temperature will be required in subsequent studies.

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Effects of Polymer in Properties of Pre-mixed Type Mortar for Concrete Repair (폴리머가 프리믹스 타입의 보수용 모르타르의 성질에 미치는 영향)

  • Song, Hyung-Soo;Lee, Chin-Yong;Min, Chang-Shik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.4
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    • pp.153-159
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    • 2006
  • Recently, the polymer is used as an admixture in the repair mortar, which contains various admixtures and mineral admixtures. In this study, the fresh and mechanical properties of repair mortar influenced by the types of polymers(classified as E.V.A.) and the range of polymer ratio were investigated. It was found that with increasing the ratio of polymer, mechanical properties(compressive strength, flexural strength, adhesive strength) of repair mortar is improved and drying shrinkage is increased.

Microstructure and mechanical properties of ternary pastes activated with multi-colors glass and brick wastes

  • I.Y. Omri;N. Tebbal;Z. Rahmouni
    • Advances in concrete construction
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    • v.17 no.3
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    • pp.167-177
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    • 2024
  • Disposal of waste glass derived from bottle or packaging glass, flat glass, domestic glass is one of the major environmental defies. Moreover, the remnants of bricks resulting from the remnants of buildings are also considered an important factor in polluting the environment due to the difficulty of filling or getting rid it. The aim of this study is to valorize these wastes through chemical activation to be an environmentally friendly material. The Microstructure, compressive strength, setting time, drying shrinkage, water absorption of different pastes produced by clear glass (CG), green glass (GG) and brick waste (BP) activated were tested and recorded after curing for 3, 7, 28 and 365 days. Five samples of pastes were mixed in proportions represented by: 100% GP (GP), 100% GGP (GGP), 100% BP (BP), 90% GP + 10% BP (GPB) and 90% GGP + 10% BP (GGPB). Various parameters considered in this study include sodium hydroxide concentrations (10 mol/l); 0.4 as alkaline liquid to binder ratio; 2.5 as sodium silicate to sodium hydroxide ratio and cured at 60℃ for 24 hours. Experimental results revealed that the addition of 10% of BP resulted in an increased strength performance of geopolymer paste especially with GGPB compared to GGP in 365 days. In addition, the 10% amount of BP increases the absorption and shrinkage rate of geopolymer pastes (GPB and GGPB) by reducing the setting time. SEM results revealed that the addition of BP and GP resulted in a dense structure.

Effect of Cement Contents and Combinations of Accelerators on Strength Development of Concrete Cured at 10℃ (10℃ 양생조건에서 단위 시멘트량 변화 및 경화촉진제의 복합사용에 따른 강도발현 성능에 관한 연구)

  • Song, Young-Chan;Lee, Tea-Gyu;Kim, Yong-Ro;Seo, Chi-Ho
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.6 no.2
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    • pp.94-99
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    • 2018
  • The purpose of this study is to investigate the effect of combinations of different accelerators mixed on the early age strength development of concrete of 21 to 27MPa in the curing temperature of $10^{\circ}C$ compared with existing early strength agent. The present study was assessed the early strength development of combinations of three different accelerating admixtures with early strength type agent comparing to single accelerating admixture with early strength type agent. As a result of this study, the effect of $CaBr_2+NaSCN+DEA$ combination on strength development showed better than $CaBr_2$ or NaSCN alone with early strength type agent. Therefore, we observed that concrete using $CaBr_2+NaSCN+DEA$ combination with early strength agent was achieved 5MPa 12hours earlier than use of $CaBr_2$ or NaSCN alone.

Properties of the Flowability and Strength of Cementless Alkali-Activated Mortar Using the Mixed Fly Ash and Ground Granulated Blast-Furnace Slag (플라이애쉬와 고로슬래그 미분말의 혼합 사용한 무시멘트 알칼리 활성 모르터의 유동성 및 강도 특성)

  • Koh, Kyung-Taek;Ryu, Gum-Sung;Lee, Jang-Hwa
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.4
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    • pp.114-121
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    • 2010
  • Portland cement production is under critical review due to high amount of CO2 gas released to the atmosphere. Attempts to increase the utilization of a by-products such as fly ash and ground granulated blast-furnace slag to partially replace the cement in concrete are gathering momentum. But most of by-products is currently dumped in landfills, thus creating a threat to the environment. Many researches on alkali-activated concrete that does not need the presence of cement as a binder have been carried out recently. However, most study deal only with alkali-activated ground granulated blast furnace slag or fly ash, as for the combined use of the both, little information is reported. In this study, we investigated the influence of mixture ratio of fly ash/ blast furnace slag tand curing condition on the flowability and compressive strength of mortar in oder to develop cementless alkali-activated concrete. In view of the results, we found out that the mixture ratio of fly ash/blast furnace slag always results to be significant factors. But the influence of curing temperature in the strength development of mortar is lower than the contribution due to other factors. At the age of 28days, the mixture 50% fly ash and 50% ground granulated blast furnace slag activated with 1:1 the mass ratio of 9M NaOH and sodium silicate, develop compressive strength of about 65 MPa under $20^{\circ}C$ curing.

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