• 콘크리트학회지
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• 제14권4호
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• pp.22-32
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• 2002

독일의 건설업자였던 마겐스(J. H. Margens)가 1903년 스타른베르그(Starnberg)에 레미콘 플랜트를 건설하고 레미콘의 제조 특허를 받은 것을 레미콘 산업의 시작으로 본다. 미국에서는 독일보다 10년 늦은 1913년 메릴랜드(Mary-land)주의 볼티모어(Baltimore)시에 플랜트의 고정 믹서로 혼합한 다음 운반하는 중앙혼합방식(central mixing system)의 레미콘 플랜트가 건설되었다. 그러나 이때는 플랜트에서 혼합하여 덤프트럭으로 운반하는 방식이었기 때문에 품질문제가 발생할 수 있어 크게 환영을 받지 못하다가 1926년에 이르러 트럭믹서의 발명으로 레미콘 산업발전의 큰 계기를 마련하였다. 초기부터 미국의 경우는 공급지역이 넓은 특징이 있어 플랜트에서 재료만 계량하여 트럭믹서에 적재하여 운반 중에 혼합하는 트랜싯 믹싱방식(transit mixing system)이 성행해 왔다.(중략)

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.105-107
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• 2012

This study was conducted to investigate the strength development of fly ash concrete using the strength development estimation for the ready mixed concrete for construction of nuclear reactors. The findings are as follows. First, the higher the curing temperature becomes, the shorter the setting time becomes. In addition, the compressive strength also increased as the curing temperature gets higher. The apparent activation energy derived from ASTM C 1074 showed 34.75 KJ/mol. The results of concrete strength estimation confirmed that Gompertz model formula has good accuracy.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.87-88
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• 2018

The change in the degree of powder in cement is very important because it plays a major role in the reaction in the concrete. In this study, we intend to apply the principle of early estimation of concrete strength using the non-middling method previously conducted to the quality evaluation of cement powder. In other words, it is proposed to analyze the potential of Hydrometer density values and the data of temperature variation in the trust solution to propose a method of acceptance inspection. According to the experimental results, the quick evaluation of the cement distributorship will be possible if the resulting regression results are used : y = 161867.4 x₁ + 117.953 x₂ - 165437 (R = 0.9158).

• KIEAE Journal
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• 제10권5호
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• pp.123-129
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• 2010

This study aimed at analyzing the trend of carbon dioxide emission for direct and indirect areas by using inter industry relations table between 2000, 2003 and 2005 in the key building materials and components. Results of this study are as follows; First, the material and components for this study was selected in 20 industries of products such as sand, gravel, cement, concrete articles, rebar, and steel bar. Second, among the 20 selected key building materials, the group with the highest carbon-dioxide emission was shown in ready-mixed concrete, concrete articles, and primary aluminum goods. Third, as a result of analyzing the changes to the units of carbon dioxide emission according to passage of time, the number of items which is changed in such as sustained increase or decrease over time was insignificant in carbon-emission change trend.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.247-250
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• 2006

Integrating a GPS based vehicle navigation system and the latest optimal algorithms, this research aims to develop a real-time decision support platform for concrete plant to provide the optimal solutions for ready mixed concrete delivery. The platform includes fleet tracking system, simulation and optimization tools, and visual interface which is useful to monitor delivery progress, to obtain crucial historical and real-time data for simulation, and to improve the efficiency of the plant operation. This paper presents configuration of the system and performance evaluation based on operational data.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.181-182
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• 2020

This study investigates the feasibility tp estimate the compressive strength at early age in hardened concrete by applying Durometer D type. The result of the experiment showed that the compressive strength reached 5MPa 6 hours, and 55 HD when the hardness was measured with the type D of the Duometer. Through this, it is expected that it will be possible to estimate the compressive strength of the initial age and measure it by the age of 28 when using the Durometer D type in the ready-mixed concrete, which will be applied in practice.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.118-119
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• 2021

In this study, we confirmed the basic characteristics of paste and mortar 1:1, 1:2, 1:3 composition using concrete sludge solid content for the purpose of developing a resource-recycling cement secondary products. The 1:2 mortar formulation showed the best compressive strength. The steam curing strength is superior in the order of C20, BS40, BS20 and Control. it is judged that the FA combination is not suitable.

• Computers and Concrete
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• 제16권3호
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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.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.403-406
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• 2003

This study is performed to evaluate the strength and nan-fracture test of the ready mixed concrete(RMC) using polypropylene. The slump is reached in $8{\pm}2cm$ of each RMC using polypropylene or without polypropylene, air content is reached in $4.5{\pm}1.5%$, the chloride content is below $0.3kg/m^3$. The compressive strength of RMC not using polypropylene is appeared over $210kgf/cm^2$ at the curing age 7 days and $239kgf/cm^2$ at the curing age 28 days. The compressive strength of RMC using polypropylene is appeared over $188kgf/cm^2$ at the curing age 7 days and $238kgf/cm^2$ at the curing age 28 days. The dynamic modulus of elasticity of RMC not using polypropylene is appeared over $298{\times}10^3kgf/cm^2$ at the curing age 7 days and $342{\times}10^3kgf/cm^2$ at the curing age 28 days. The RMC using polypropylene is appeared over $284{\times}10^3kgf/cm^2$ at the curing age 7 days and $238{\times}10^3kgf/cm^2$ at the curing age 28 days. The pulse velocity of RMC not using polypropylene is appeared over 4,198m/s at the curing age 7 days and 4,382m/s at the curing age 28 days. The RMC using polypropylene is appeared over 4,182m/s at the curing age 7 days and 4,342m/s at the curing age 28 days.

• 한국산학기술학회논문지
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• 제16권2호
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• pp.1461-1468
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• 2015

대규모 갱도의 보강을 위해 현재 일반적인 광산 지보재(록볼트 및 강지보재)가 대부분 적용되고 있으며, 일부에서는 현장타설 숏크리트로 연약지반 보강을 실시하고 있다. 그러나 광산 갱도 굴착 후 매번 숏크리트를 타설할 수는 없는 국내 광산 여건상 경제성 및 부지확보의 문제로 고정적인 현장 배치플랜트를 확보하지 못하고, 인근 레미콘 제조 공장에서 배합된 숏크리트 재료를 공급받아 시공하고 있다. 그러나 레미콘 제조 공장에서 운반되는 숏크리트는 이동 거리 및 시간에 따라 품질이 저하되고, 광산 시공 현장에 상주하는 전문 품질관리자의 부재로 시공 품질 관리에 어려움이 많은 실정이다. 따라서 본 논문에서는 혼화재료의 종류와 혼입률을 변수로 선정하여 숏크리트의 역학적 특성과 단기 내구성 평가를 위한 실내실험을 실시하였다.