• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.647-650
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• 2001

The purpose of this study was the influence of cold weather ready mixed concrete quality according to needs of customer were investigated by measurements of slump, air content, temperature and compressive strength. As a results, cold weather ready mixed concrete using high standard admixtures, high early strength admixtures and cold weather concrete plant were similarly to slump, air content, temperature and compressive strength.

• Computers and Concrete
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• 제21권2호
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• pp.139-147
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• 2018

Due to enhanced construction requirement, ready mixed concrete are being popular day by day. The current study aimed to develop ready mixed concrete using GBFS contained cement and determine its properties of fresh and hardened states. A real scale experiment was set up in a ready mixed plant for measuring workability and compressive strength. The workability was tested after mixing (within 5 minutes), 30, 60, 90, 120 and 150 minutes of the running of bulk carrier. The ready mixed carrier employed spinning motion i.e., rotating around its axis with 20 RPM and running on road with 1km/h speed. The mixing ratio of cement: sand:gravel, water to cement ratio, super plasticizer were, 1:1.73:2.47, 0.40 and 6% of cement, respectively. The chemical composition of raw material was determined using XRF and the properties of cements were measured according to ASTM standards. The experimental results confirm that the cement with composition of 6.89% of GBFS, 4% of Gypsum and 89.11% of clinker showed the good compressive strength and workability of concrete after 150 minutes of the spinning motion in bulk carrier.

• 한국안전학회지
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• 제29권4호
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• pp.123-131
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• 2014

Whole amount of waste water, approximately 921.6 liter, for cleaning a ready mixed concrete truck should be used to produce concrete as a mixing water or cleaning water. Recycling water for concrete mixing contains solids, which cause decrease in slump, air and compressive strengths, so it may influence on poor concrete quality. Therefore, it has been maintained to use recycling water with less than 3 percent of solids. Since no evaluation system has been constructed to directly reflect on variability of recycling water from ready mixed concrete plants, it is necessary to develop "Automatic recycling solid measuring system" for quality controls in real time. In this research, sensors measuring waste water concentration in ultrasonic and inductance methods were developed, and automatic system using the sensors were established. The accuracy of measurement sensors developed for recycling water based on various conditions of concentration was proved, and application limits were evaluated. Also, concentration of recycling water using sensors developed from ready mixed concrete plant was measured, and curing method verified the accuracy of the sensors. Moreover, measurement sensors for recycling water in various locations were installed to evaluate the effects on measuring method and spots. The automatic measuring system for recycling water concentration, which is developed in the research, will contribute to improve concrete quality safety through reliable solids maintenance.

• 한국응용과학기술학회지
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• 제30권4호
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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.

• 한국응용과학기술학회지
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• 제33권2호
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• pp.239-246
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• 2016

본 연구에서는 건축폐기물로 분류되는 레미콘회수수를 재활용함과 동시에 지구온난화의 주범인 $CO_2$의 자원화를 위한 시스템의 공정최적화를 진행하였다. 레미콘회수수를 이용한 액상탄산화 반응에서 가장 중요한 공정은 $Ca^{2+}$를 용출하는 공정이다. 일정량의 레미콘회수수를 이용해 고순도의 $CaCO_3$을 생성하기 위해 $Ca^{2+}$ 용출시 질산에 의해 낮아지는 pH 농도를 기준으로 실험을 진행하였으며, $CO_2$는 발전기 배기가스를 이용해 MEA용액에 포집하였다. 본 연구를 통해 1톤의 레미콘회수수에서 최대 11 kg의 $CaCO_3$를 합성할 수 있었다. 생성된 $CaCO_3$ 분석결과 제지용으로 사용 가능한 것을 확인하였다.

• 레미콘
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• 6호통권20호
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• pp.114-119
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• 1989

• 콘크리트학회지
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• 제15권2호
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• pp.6-7
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• 2003

• 한국구조물진단유지관리공학회 논문집
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• 제26권5호
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• pp.103-111
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• 2022

미세먼지는 생태학적으로 심각한 문제를 발생시키는 원인이고, 건설현장에서 발생되는 비산먼지는 국내 미세먼지의 주요 발생원이다. 그러나 레미콘 플랜트 현장을 포함한 건설현장에서는 비산먼지 발생단계에서 모니터링은 거의 이루어지지 않고 있으며, 방진덮개, 방진벽 및 방진망, 살수시설, 세륜시설 등 수동적인 제거 방안들이 대부분인 실정이다. 비산먼지는 발생한 뒤 퍼지고 나면 관리하는 것이 매우 어렵기 때문에 발생을 억제하거나 발생단계에서 즉시 제거하는 것이 매우 중요하며, 비산먼지 발생단계에서 실시간 모니터링을 통해 발생 경향을 파악한 뒤 비산먼지 억제 및 제거를 위한 환경 유지관리 대책을 세우는 것이 필요하다. 따라서, 본 연구에서는 레미콘 플랜트의 비산먼지 환경 유지관리를 위하여 골재하차장을 중심으로 비산먼지 질량농도를 모니터링하고 발생 경향을 분석하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.845-848
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• 2008

In this study, through the Batch Plant in field which is carrying out in the country, this research is going to grope the development of Ready-mixed Shotcrete that can improve the construction of shotcrete, and long-term durability. Accordingly, in this study, the Batch Plant in field which is only for shotcrete will be chosen in random so that can be aware the problems of the Batch Plant in field, and when the results come out, the shotcrete system will be prepared that is based on the results of rsearch, and also can be used in preparation index of shotcrete. Moreover, the results will be able to improve an efficent tool that can increase shotcrete quality.

• 한국구조물진단유지관리공학회 논문집
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• 제3권1호
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• pp.163-169
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• 1999

The object of this study is to compare properties of massive fly-ash concrete with plain concrete. Two concrete mixtures comprising two batch each $1.0m^3$ in volume, were made from ready mixed concrete batch plant. The water-to-cementitious materials ratio was kept constant at 51.4%. Therefore, massive concrete specimen($W800{\times}D800{\times}H800mm$) was cast from ready mixed concrete to analyze history of temperature and core strength properties. Bleeding, time of slump loss and time of setting of the fresh concrete were measured. In order to estimate the properties of massive fly-ash concrete in hardened concrete, non-destructive tests such as rebound hardness, ultrasonic pulse velocity and maturity were performed and analyzed.