• Magazine of the Korea Concrete Institute
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• v.14 no.4
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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)

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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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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• v.10 no.5
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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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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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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• 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.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1461-1468
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• 2015

Mostly mine support(Rock bolt and Support) which is currently general for reinforcements of a large scale tunnel is applied, Some executing a reinforcement to Poor ground by cast-in-place shotcrete. However On domestic mine conditions that couldn't having every time after mine tunnel excavation, it couldn't ensure the field batch plant which is a fixed in an issue of economies and site security, constructing it by supply gets from shotcrete materials combined in neighborhood ready mixed concrete manufacturing plants. carried shotcrete in ready mixed concrete manufacturing plants as migration length and time are falling off in quality. But, it is difficult for construction quality control By quality control arbitrariness absence at on-scene. In the present study, carry out Laboratory Test by kinds and percentages of accelerating agent for evalution of Mechanical Property and Durability of Shotcrete.