• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.2
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• pp.23-34
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• 1986

Multiple regression equation was derived for estimation of slump loss in ready mixed concrete and usefulness of the equation was verfied by field test. Factors affecting slump loss were examined and analyzed for transport distance and transport time of ready mixed concrete. The analysis showed that wait and discharge time of ready mixed concrete in job site caused difficulty in the slump control. To determine the influence of the other factors such as mix proportion, temperature of concrete, and dosage of admixture, experimental tests were performed. Generally, there was no significant difference in slump loss according to cement content and initial slump level. For one retarder, more slump loss was found, but difference according to dosage of admixture was not recognized.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.3
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• pp.133-142
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• 2006

The purpose of this study is to predict the fracture energy in accordance with the combination variables by applying the mix design nomogram in ready mixed concrete products. In terms of the experiment for drawing up Mix Design Nomogram, the beam is manufactured based on the mixture table described in the specifications of ready mixed concrete manufacturing company and a three-point bending test suggested in RILEM 50-FMC Committee is performed. As a result, this study makes sure the possibility to apply the mix design nomogram that is possible to predict the fracture energy in ready mixed concrete products and enables one to achieve the automation of the design of mixture for the production of ready mixed concrete products with the development of program using it.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.243-246
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• 2000

In this study, the influence of workability and strength of the concrete according to change temperature of portland cement were investigated by measurements of slump, air content and compressive strength.. As a result, ready mixed concrete using 5-20% mineral admixtures such as fly ash, blast furnace slag were desirable to prevent the increase in workability and strength of concrete in summer season

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.1
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• pp.69-78
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• 1986

The properties of ready mixed concrete are affected largely by quality of cement, grading and adhesive surface area water content of aggregate. The amount of variation must be found as soon as possible to minimize the variation of concrete properties. In this paper, a computer program is presented for fast and accurate calculation and modification of mix proportion according to property variation of concrete materials. The program calculates specified mix proportion, job mix proportion and batch weight of ready mixed concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.243-244
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• 2023

The quality of ready-mix concrete, a decisive factor in the performance of a structure, has recently been ensured by considering the unit water testing method, and this study experimentally examined the reliability of evaluation results based on this method.

• Magazine of the Korea Concrete Institute
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• v.14 no.4
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• pp.14-21
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• 2002

국내에서 시공되는 콘크리트 구조물의 대부분은 레미콘(ready-mixed concrete)으로 시공되고 있기 때문에 레미콘의 품질관리(quality control) 및 품질확보(quality security)는 곧 콘크리트 구조물의 품질과 내구성의 확보를 위해 매우 중요한 사항이다. 최근 콘크리트 구조물의 잦은 사고로 인해 콘크리트의 품질문제가 사회문제로 나타나고 있으며 이에 대비한 콘크리트 품질보증 시스템의 확립이 시급한 실정이다. 그러나 레미콘의 품질환경은 원재료의 품질저하, 레미콘 운반시간의 증대 및 기술개발의 미흡 등 주변여건이 좋은 편은 아니며 레미콘 산업도 경쟁시대에 돌입하면서 레미콘 품질이나 기술우위의 시대로 변화되고 있다.(중략)

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.770-778
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• 2013

In this study, a liquid carbonation method was applied for producing precipitate calcium carbonate by liquid-liquid reaction. We recycled the recycling water of ready-mixed concrete, one of construction waste for use source of carbonate ion. A supernatant separated from the recycling water of ready-mixed concrete, as a result of ICP analysis of a cation, $Ca^{2+}$ was contained up to 1100 ppm. We used MEA as a $CO_2$ absorbent for the liquid carbonation. A precipitate $CaCO_3$ was produced at more than MEA 20 wt%. The precipitate $CaCO_3$ as a final product was separated and dried. The result of XRD was confirmed the generation of $CaCO_3$ to calcite structure.

• Proceedings of the Korea Concrete Institute Conference
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• 1989.10a
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• pp.35-38
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• 1989

The purpose of this report is to investigate and analyze development and achievement of flowing and high-strength concrete by reacy mixed concrete companies in Korea. For this purpose, the investigation was divided into three parts, i.e., superplasticizers, flowing concrete, high-strength concrete. And, they were asked to quality control manager in ready mixed concrete companies. Many researches have been carried out. And, flowing concrete is applied to field in a few case. In order to improve practical applicability of high-strength concrete and make concrete strength higher, to begin with, profound research for concrete ingredients will be needed along with presentation of methods for obtaining workability and quality assurance.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.239-246
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• 2016

In this study, recycling sludge water of Ready-mixed concrete, and was carried out to optimize the system for recycling of the $CO_2$. The most important process in the liquid phase using a carbonation reaction can be recovered ready-mixed concrete is a process for the $Ca^{2+}$ release. $Ca^{2+}$ concentration of the experiment relative to the pH being lowered by the acidic substance during elution was performed. $CO_2$ was trapped in the MEA solution using a generator flue gas. In ready-mixed concrete can be synthesized $CaCO_3$ up to 11kg/1ton. The resulting $CaCO_3$ analysis results show that it is possible to use paper industry.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.211-212
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• 2009

In this study, the fresh properties and compressive strength of Strain-Hardening Cement Composites is compared between manufactured by ready-mixed concrete batcher mixer and small mixer in laboratory.