• Title/Summary/Keyword: ready-mix

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A Study on the Characteristics of Recycled Aggregate Concrete According to the Mixing Ratio of Recycled Fine Aggregate at Specific Concrete Strengths (설계기준강도별 순환 잔골재 혼합비율에 따른 순환골재 콘크리트 특성에 관한 연구)

  • Sang-Hyuck, Yoon;Sea-Hyun, Lee
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.10 no.4
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    • pp.367-375
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    • 2022
  • In this study, the characteristics of recycled aggregate concrete according to the mixing ratio of recycled fine aggregate were analyzed by design strength to explore its use in the production of ready-mixed concrete. The results show that, depending on the ratio of recycled aggregate, the compressive strength is similar to that of normal concrete and does not deteriorate. Therefore, it is possible to achieve a strength similar to the target design strength. Furthermore, if the ratio of recycled fine aggregate for concrete is up to 25 % of the total aggregate amount (50 % of the to-tal fine aggregate), slump does not cause problems. Our findings show that the higher the de-sign standard strength, the greater the amount of powder, and management of slump reduction, unit quantity, and performance system is necessary. The obtained results show that recycled ag-gregate can be used for the production of ready-mixed concrete after adjusting its mixing ratio and concrete mix proportions.

Analysis of Damage Levels with Bond Performance between Reinforcement and Recycled Coarse Aggregate Concrete (순환굵은골재 콘크리트와 이형철근의 부착거동시 손상단계 분석)

  • Lee, Min-Jung;Yun, Hyun-Do;JAng, Yong-Heon;Choi, Ki-Sun;You, Young-Chan;Lee, Do-Heun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.863-866
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    • 2008
  • One of the most important requirements for reinforced concrete constructions is the bond behavior between concrete and reinforcement. In this study, the positions (i.e., vertical, horizontal) and the locations (i.e., 225mm and 75mm) of reinforcement were considered as a main test parameter. The ready mixed recycled aggregate concrete concrete with specified strength of 21MPa was prepared with different replacement ratio(i.e 0%, 100%) of recycled coarse aggregate. From the test results, it was bond that under the same mix proportion (i.e., the mix proportions are the same, except for deformed bars position), the bond strength between the recycled coarse aggregate concrete and the reinforcement has obvious relation with reinforcement position. Also, the specimens of top position showed a lower bond stress than that provided in CEB-FIP Code.

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The Actual Wearing Conditions and Preferred Design of Tailored Jackets for Obese Women in Their 20s and 30s (20~30대 비만여성의 테일러드 재킷 착용실태 및 선호디자인)

  • Oh, Young-Soon;Lee, Jeong-Ran
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.9
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    • pp.1479-1490
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    • 2010
  • This study provides basic data for the development of jacket patterns which reflect designs corresponding to the body shape features and preferences of obese women in their 20s and 30s by understanding problems they may encounter in wearing a ready-made jacket by researching the reality of ready-made tailored jacket wearing and their design preferences. A survey was conducted by sampling 82 obese women (over $25kg/m^2$ BMI) between the ages of 20 to 39. The details of the survey consists of general information, interest rate and importance rate on clothes, reality of wearing and purchasing jackets, measurement fits per each part, and preferred designs. SPSS 14.0 was used to analyze the data. The results showed that 76.8% of obese women wore their jackets less than 5 times a month. Those in the 20s wore the jackets more frequently than those in the 30s. The reasons for not wearing jackets frequently included uncomfortableness in activities and unavailability of the correct size. A total of 55% of the total preferred the fitting to be relatively smaller than the body size or tightly fitting. Although in the past, there was a tendency to wear a loose fit to cover the body shape, currently even obese body shapes avoided the loose fit as the tight fit is the trend. In terms of the satisfaction rate for the measurements per each part of jackets, there was a low satisfaction rate for most of the items. For the circumference items such as waist length and chest size, people responded that they were too small and for the length of items such as the length of jacket and sleeve length, people responded that they were too long. This was because the readymade clothes brands increase the length of items and circumference items in uniform in the same intervals when producing large sizes. Both those in the 20s and the 30s preferred a tight fit. In terms of preferred fabric, a wool/spandex mix was most popular and then cotton/spandex. This shows that they prefer those fabrics which allow an excellent activity while maintaining the exterior well. In addition, they preferred black color with no patterns because they wanted their body size to look reduced and did not want to receive any attention.

Comparative Study of GPS-Integrated Concrete Supply Management using Discrete Event Simulation

  • Zekavat, Payam Rahnamayie;Mortaheb, Mohammad Mehdi;Han, Sangwon;Bernold, Leonhard
    • Journal of Construction Engineering and Project Management
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    • v.4 no.2
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    • pp.31-40
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    • 2014
  • The management of vehicular supply of "perishable" construction material, such as concrete mixes, faces a series of uncertainties such as weather, daily traffic patterns and accidents. Presented in this paper is a logistics control model for managing a hauling fleet with interrelated processes at both ends and queue capacities. Discrete event simulation is used to model the complex interactions of production units and the randomness of the real world. Two alternative strategies for ready mix concrete delivery, with and without an off-site waiting queue, are studied to compare supply performance. Secondly, the paper discusses the effect of an agent-based GPS tracking system providing real-time travel data that lessens the uncertainty of trucking time. The results show that the combination of GPS information with off-site queuing reduces productivity loss and process wastes of concrete placement as well as the idleness of supply trucks when crew or pump experience an unexpected stoppage.

A experimented study on Rapid-Setting Flowable Material (급결성 유동화처리토의 특성에 관한 실험적 연구)

  • Lee, Sang-Il;Cho, Dae-Ho;Han, Sang-Jae;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1295-1302
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    • 2006
  • Controlled low-strength material(CLSM) which is easily excavated and also known as flowable material, is commonly used as a backfill in utility trenches and other applications. In this study, a rapid-setting flowable material a kind of CLSM made with a field soil were evaluated by an experimental study. The properties ordinarily desired from the mix are: (a) flow under gravity; (b) hardening for early workability(after 4 hours)and cover; and (c) ultimate strength low enough to allow ready excavation. Fluidity of fresh material is evaluated using a simple spread test. Hardening is measured by a mortar penetrometer, and these values are correlated with unconfined compressive strength. It is desirable to keep the ultimate strength to less than $5.6kg/cm^2$ somewhat less target strength is selected for the 28-day value.

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A Study on the Development of Direct Marketing Strategy for Organic Agricultural Products (유기농산물 직거래전략 개발에 관한 연구)

  • Yoo, Duck-Ki
    • Korean Journal of Organic Agriculture
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    • v.19 no.4
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    • pp.475-500
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    • 2011
  • One of the first important strategic decisions when a starting an organic marketing initiative (OMI) is to plan the right strategy for distributing products. This decision depends to a large extent on whether the OMI has chosen a quality-premium product strategy or a price-quantity strategy. All distribution decisions interact strongly with other aspects of the marketing mix. Where and how a product is distributed objectives, its chosen strategy and the availability of human and capital resources. To select a market channel, frequent contact and discussions with possible partner are important. Generally, a distribution is made between the direct and indirect physical distribution of organic products to consumers. The longer the supply chain, the lower the chances that an OMI can steer the market through its own marketing measures and convince consumers through its own promotion activities. Generally speaking, the shorter the chain between OMI products and the final consumer, the less dependent the OMI will be on the success of other market actors. Direct selling activities to the retail or food industries also requires an OMI to undertake additional processing and marketing activities. For example, retailers often expect products to have been packed and labelled ready for sale. To conclude, distribution channels should be chosen in accordance with the product and price policy as well as the management capacity of the OMI.

Concrete properties prediction based on database

  • Chen, Bin;Mao, Qian;Gao, Jingquan;Hu, Zhaoyuan
    • Computers and Concrete
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    • v.16 no.3
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    • pp.343-356
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    • 2015
  • 1078 sets of mixtures in total that include fly ash, slag, and/or silica fume have been collected for prediction on concrete properties. A new database platform (Compos) has been developed, by which the stepwise multiple linear regression (SMLR) and BP artificial neural networks (BP ANNs) programs have been applied respectively to identify correlations between the concrete properties (strength, workability, and durability) and the dosage and/or quality of raw materials'. The results showed obvious nonlinear relations so that forecasting by using nonlinear method has clearly higher accuracy than using linear method. The forecasting accuracy rises along with the increasing of age and the prediction on cubic compressive strength have the best results, because the minimum average relative error (MARE) for 60-day cubic compressive strength was less than 8%. The precision for forecasting of concrete workability takes the second place in which the MARE is less than 15%. Forecasting on concrete durability has the lowest accuracy as its MARE has even reached 30%. These conclusions have been certified in a ready-mixed concrete plant that the synthesized MARE of 7-day/28-day strength and initial slump is less than 8%. The parameters of BP ANNs and its conformation have been discussed as well in this study.

Butterfly Image Fashion Design in the Fashion Designer Brand 'Alexander McQueen' (패션 디자이너 브랜드 '알렉산더 맥퀸' 작품에 나타난 나비 이미지 패션 디자인)

  • jeon, Semi;Yum, Haejung
    • Journal of Fashion Business
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    • v.23 no.4
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    • pp.24-37
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    • 2019
  • This study focused on the fashion designer brand 'Alexander McQueen' to determine how butterflies are used in modern fashion through the sensibilities of certain designers. To this end, both a literature review and empirical research were conducted. First, we examined the origin of the word and appearance characteristics of butterflies based on prior research and a book, and also surveyed the tendencies used by the fashion designer brand Alexander McQueen. Second, out of 239 items announced by the fashion designer brand "Alexander McQueen" RTW (Ready to Wear) ranging from the S/S Collection in 2008 to the 2018-9 F/W collection, 73 pieces deemed to be fashion using butterfly images were collected through www.samsung.net and www.firstview.com, then analyzed based on timing and aesthetic characteristics. Results. The analysis by time period was divided into fantasy, handicraft, mix and match, and aesthetic characteristics shown in the order of compromise beauty, rhythmical beauty, and voluptuous beauty. The purpose of this study was to determine how butterflies are expressed in fashion based on the sensibility of a specific designer in modern fashion, the fashion designer brand 'Alexander McQueen'. Based on the results of this study, we hope that the information presented herein on fashion of natural images will serve as a basic material for similar research or design ideas as an example of designs based on butterfly images.

Analysis of the Characteristics of Manufactured Concrete, according to the Type of Admixture used when Remixing and Placing it (혼화제 종류별로 제조된 콘크리트의 재 혼합 타설시 특성 분석)

  • Ryu, Hyun-Gi;Shin, Sang-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.5
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    • pp.95-102
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    • 2010
  • In recent years, the demand for the development of high quality and cost effective materials, as well as the competition to ensure a diverse and sufficient amount of ready-mixed concrete, has been increasing rapidly. In this experiment, concretes made with different admixtures are blended with each other in different combinations and ratios, in order to identify potential problems. The first test was a slump level test, in which all of the concretes met the required numbers, as they also did in the test for air content. Plain organic acid concrete scored the highest in bleeding amount, but organic acid mix in general showed a similar outcome. In the early measurement of compressive strength, plain naphthalene concrete was the strongest. Of the blends, the 5:5 mix of organic acid and naphthalene was the strongest. In the standard measurement, the 5:5 mix of naphthalene and lignin was the strongest. Tensile strength tests revealed similar results. Length change rate proved to be greater in blended concrete than in plain concrete, and dry shrinkage rate was highest in the 7:3 ratio blends. Through SEM photo analysis, it was confirmed that the 7:3 ratio blends contained more micro-voids. In conclusion, with the exception of a specific few combinations, it was found that the blending of different types of concrete is undesirable due to the delayed coagulation time as well as the early decrease in strength.

Prediction on Mix Proportion Factor and Strength of Concrete Using Neural Network (신경망을 이용한 콘크리트 배합요소 및 압축강도 추정)

  • 김인수;이종헌;양동석;박선규
    • Journal of the Korea Concrete Institute
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    • v.14 no.4
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    • pp.457-466
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    • 2002
  • An artificial neural network was applied to predict compressive strength, slump value and mix proportion of a concrete. Standard mixed tables were trained and estimated, and the results were compared with those of the experiments. To consider variabilities of material properties, the standard mixed fables from two companies of Ready Mixed Concrete were used. And they were trained with the neural network. In this paper, standard back propagation network was used. The mix proportion factors such as water cement ratio, sand aggregate ratio, unit water, unit cement, unit weight of sand, unit weight of crushed sand, unit coarse aggregate and air entraining admixture were used. For the arrangement on the approval of prediction of mix proportion factor, the standard compressive strength of $180kgf/cm^2{\sim}300kgf/cm^2$, and target slump value of 8 cm, 15 cm were used. For the arrangement on the approval of prediction of compressive strength and slump value, the standard compressive strength of $210kgf/cm^2{\sim}240kgf/cm^2$, and target slump value of 12 cm and 15 cm wore used because these ranges are most frequently used. In results, in the prediction of mix proportion factor, for all of the water cement ratio, sand aggregate ratio, unit water, unit cement, unit weight of sand, unit weight of crushed sand, unit coarse aggregate, air entraining admixture, the predicted values and the values of standard mixed tables were almost the same within the target error of 0.10 and 0.05, regardless of two companies. And in the prediction of compressive strength and slump value, the predicted values were converged well to the values of standard mixed fables within the target error of 0.10, 0.05, 0.001. Finally artificial neural network is successfully applied to the prediction of concrete mixture and compressive strength.