레미콘 품질 실시간 정보공유 및 물류비용절감 위한 현장배치플랜트 분할 제조에 관한 연구

백종관,김병찬 한국엔터프라이즈아키텍처학회 2023 정보기술아키텍처연구 Vol.20 No.3

This study proposes a plan for separate production at a field batch plant and logistics operation to introduce a management system for a ready-mixed concrete batch plant capable of sharing information about the location of ready-mixed concrete production, the quality of ready- mixed concrete, the size of a construction site, and the transportation environment of ready-mixed concrete via an ERP system or in real time and to flexibly apply it according to analysis results. The study developed a logistics rationalization plan by improving the empty transfer rates of vehicles including cargo trucks, such as dump trucks, that would have a certain percentage of materials including aggregate and cement supplied from a field batch plant at a construction site along with the production of a fixed batch plant, make ready-mixed concrete at a field batch plant, supply it to the construction site, and to gain a return after material procurement costs, ready-mixed concrete quality, transportation costs of ready-mixed concrete, and the delivery of ready-mixed concrete. The analysis results demonstrate that logistics operation based on separate production at a field batch plant proposed in the study saved logistics costs considerably more than the production of ready-mixed concrete at the old field batch plant.

배합표에 의한 혼화재를 사용한 콘크리트의 압축강도 추정 : 경기북부지역 레미콘을 대상으로 Ready-Mixed Concrete In the North District of Gyeonggi

임창훈,지남용,조홍범 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

Nowadays we substitutes fly-ash and ground granulated blast furnace slag for cement as an admixture more and more due to the reduction of hydration heat, a unite cost reduction, and strength enhancement in the ready-mixed concrete plant. However, concrete replaced with fly-ash or ground granulated blast furnace slag reduces the early strength and increases the long time strength compare with the concrete only used ordinary Portland cement. Furthermore this actual state doesn't be considered in the ready mixed concrete factory. The data considered in this study constitutes 110 kind of mix designs, 11459 of compressive strength data, specified compressive strength of concrete from 210 to 350 kgf/cm², and slump from 8 to 18 cm produced in the ready mixed concrete plant in the north district of Gyeonggi, especially in Yangju and Paju. Therefore this study contributes to predict compressive strength based on the mix design and quality test results in the laboratory through multiple linear regression analysis of stepwise method in order to control quality of concrete containing admixture properly.

Evaluation on Protection Performance and On-Site Applicability of Hybrid Fiber-Reinforced Concrete

Dongyeop Han,Yong-Jun Park,Min-Cheol Han,Seong-Tae Yi 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.3

The aim of this research is to evaluate the protecting performance of hybrid fiber-reinforced concrete against lateral forces such as explosives or flying objects. The objective of this research is to better prepare this concrete for use in the ready-mix concrete industry. Even though the fiber addition gives it strong mechanical properties, it also decreases workability due to the inefficient dispersion of fibers. Therefore, it has been difficult to apply to the readymix concrete plant’s mixing, delivery and on-site placement. The authors have developed a combined steel and polyaramid fiber that gives the favorable protection needed against high-impact forces and provides a suitable workability for the ready-mix concrete system. To evaluate the required performance, the hybrid fiber-reinforced concrete specimen was subjected to high-speed projectiles and had its workability and performance tested on a construction site of an established ready-mix concrete company. The hybrid fiber-reinforced concrete successfully provided the protection capabilities sought for the finished product and provided a workable-ready mix applicability.

Forensic-based investigation-optimized extreme gradient boosting system for predicting compressive strength of ready-mixed concrete

Chou Jui-Sheng,Chen Li-Ying,Liu Chi-Yun 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.1

Regulations mandate testing concrete’s compressive strength after the concrete has cured for 28 days. In the ideal situation, cured strength equals the target strength. Advanced estimation of concrete’s compressive strength can facilitate quality management, improve safety, and present economic advantages in sustainable use. Basic statistical methods cannot effectively predict concrete’s strength or its non-linear relationships with the proportions of its constituent materials. In this study, a baseline model for predicting concrete’s compressive strength was constructed using a state-of-the-art machine-learning method. Most related studies have used sets of concrete mix design results concerning concrete specimens for laboratory-produced concrete specimens as training sets and have obtained simple models through regression; however, these models have been unsuitable for onsite prediction of the compressive strength of concrete with the various mix designs. Control over mix proportions is high in laboratories, resulting in low variation; onsite manual operation and environmental factors cause significant variations in assessment data. In this study, machine-learning techniques and a newly developed metaheuristic optimization algorithm were applied to big long-term data from 75 concrete plants to construct the optimal machine-learning model. Our self-developed forensic-based investigation algorithm was employed to fine-tune the hyperparameters of the extreme gradient boosting model and to improve the model’s generalizability. The lowest mean absolute percentage error (MAPE) obtained using this model was 9.29%, which was smaller than the lowest MAPE achieved using the conventional simple regression with the water-to-binder (W/B) ratio (12.73%). The traditional method tends to overestimate the actual compressive strength. Finally, a convenient expert system was developed that facilitates the use of the proposed model by onsite engineers for quality management. This system expedites the judgment of whether a mixed design is reasonable, reducing production costs while maintaining the safety of concrete structures. It can be widely applied in practice and function as an effective decision-making tool.

고품질 순환골재 활용에 따른 건설 산업의 경제적 효과 및 순환골재 생산 산업의 비용 편익 분석

최원영(Won-Young Choi),전찬수(Chan-Soo Jeon),김상헌(Sang-Heon Kim),김태형(Tae-Hyoung Kim),전덕우(Duk-Woo Jeon) 한국건설순환자원학회 2021 한국건설순환자원학회 논문집 Vol.9 No.4

본 연구는 순환골재의 고품질 사용 활성화를 위해 품질확보 기술의 뒷받침을 전제로 하여 순환골재의 활용에 따른 건설 산업의 경제적 효과 및 순환골재 생산 산업의 가치 증대 영향을 분석을 목적으로 한다. 이에 고품질 순환골재 활용을 통해 얻을 수 있는 레미콘 생산비용을 순환골재 품질기준에서 권고한 순환골재 적용 비율에 따라 분석하고, 국내 레미콘 산업규모와 순환골재 물량 충족률을 파악하여 일반레미콘과 순환골재 적용 레미콘 산업의 경제적 효과를 분석하였으며, 비용 편익 분석법을 활용하여 고품질의 순환골재 생산 및 판매에 따른 편익을 검토하였다. 그 결과 레미콘 생산비용은 적용 비율에 따라 2.3∼16.2%의 절감효과를, 순환골재 활용에 따른 건설 산업의 경제적 효과는 약 1,068∼1,426억 수준을, 순환골재 생산 산업의 가치 증대 영향은 약 1.22배 편익을 발생시켰다. The purpose of this study is to analyze the economic effect of the use of recycled aggregate on the construction industry and the effect of increasing the value of the recycled aggregate production industry on the premise of supporting quality assurance technology to promote the high-quality use of recycled aggregate. Accordingly, the production cost of ready-mixed concrete that can be obtained through the use of high-quality recycled aggregate is analyzed according to the recycled aggregate application rate recommended in the recycled aggregate quality standard, The economic effect of general ready-mixed concrete and recycled aggregate-applied ready-mixed concrete industry was analyzed by identifying the domestic ready-mixed concrete industry scale and the rate of satisfaction of recycled aggregate volume, and a cost-benefit analysis method was used to examine the benefits of high-quality recycled aggregate production and sales. As a result, the production cost of ready-mixed concrete is reduced by 2.3∼16.2% depending on the application rate, the economic effect of the use of recycled aggregate on the construction industry is about 106.8∼142.6 billion KRW, and the effect of increasing the value of the recycled aggregate production industry generated about 1.22 times the benefit.

미세먼지 발생 레미콘시설에서의 대기확산모델 CALPUFF와 AERMOD 비교 분석

한진희(Jin-hee Han),김영희(Younghee Kim) 한국환경보건학회 2021 한국환경보건학회지 Vol.47 No.3

Objectives: Using atmospheric dispersion representative models (AERMOD and CALPUFF), the emissions characteristics of each model were compared and analyzed in ready-mixed concrete manufacturing facilities that generate a large amount of particulate matter (PM-10, PM-2.5). Methods: The target facilities were the ready-mixed concrete manufacturing facilities (Siheung RMC, Goyang RMC, Ganggin RMC) and modeling for each facility was performed by dividing it into construction and operation times. The predicted points for each target facility were selected as 8-12ea (Siheung RMC 10, Goyang RMC 8, and Gangjin RMC 12ea) based on an area within a two-kilometer radius of each project district. The terrain input data was SRTM-3 (January-December 2019). The meteorological input data was divided into surface weather and upper layer weather data, and weather data near the same facility as the target facility was used. The predicted results were presented as a 24-hour average concentration and an annual average concentration. Results: First, overall, CALPUFF showed a tendency to predict higher concentrations than AERMOD. Second, there was almost no difference in the concentration between the two models in non-complex terrain such as in mountainous areas, but in complex terrain, CALPUFF predicted higher concentrations than AERMOD. This is believed to be because CALPUFF better reflected topographic characteristics. Third, both CALPUFF and AERMOD predicted lower concentrations during operation (85.2-99.7%) than during construction, and annual average concentrations (76.4-99.9%) lower than those at 24 hours. Fourth, in the ready-mixed concrete manufacturing facility, PM-10 concentration (about 40 µg/㎥ ) was predicted to be higher than PM-2.5 (about 24 µg/㎥ ). Conclusions: In complex terrain such as mountainous areas, CALPUFF predicted higher concentrations than AERMOD, which is thought to be because CALPUFF better reflected topographic characteristics. In the future, it is recommended that CALPUFF be used in complex terrain and AERMOD be used in other areas to save modeling time. In a ready-mixed concrete facility, PM-10, which has a relatively large particle size, is generated more than PM-2.5 due to the raw materials used and manufacturing characteristics.

레미콘 슬러지를 활용한 콘크리트블록 활용에 대한 기초 연구

정재호 한국건축시공학회 2019 한국건축시공학회지 Vol.19 No.4

Sludge generated in the production of ready-mixed concrete is classified as waste and processed at a high cost. In particular, small and medium-sized ready-mix manufacturer are burdened with such costs, and some companies are illegally processing them. Therefore, the purpose of this study is to suggest a method for recycled remicon sludge as a concrete block composition. When the remicon sludge is simply dried, the residual chemical admixture and ettringitee contained in the sludge are present, so that the compressive strength of the concrete block and the compressive strength after freezing and thawing are largely deteriorated to meet the quality standards of the concrete shore and retaining wall block It was not possible to do. As a method for satisfying the physical performance, it was found that the remicon sludge was calcined at a high temperature of about 900 ° C. to decompose ettringite and residual chemical admixture and then used it. 레미콘 제조 시 발생되는 슬러지는 폐기물로 분류되어 높은 비용을 지불하며 처리를 하고 있다. 특히 중소레미콘 업체에서는 이 비용이 큰 부담으로 작용되며, 일부 업체에서는 불법적인 처리가 발생되고 있는 실정이다. 따라서 본 연구에서는 레미콘슬러지를 콘크리트블록용 조성물로 재활용하는 방법을 제시 하는데 그 목적이 있다. 레미콘슬러지를 단순 건조하여 사용 하였을 때에는 슬러지에 포함된 잔류화학혼화제와 에트린가이트가 존재하여 콘크리트블록의 압축강도, 동결융해 후 압축강도 물리적성능이 크게 떨어져 콘크리트호안 및 옹벽블록의 품질기준을 만족하지 못하는 것으로 나타났다. 물리적 성능을 만족시키기 위한 방법으로 레미콘슬러지를 900℃정도의 고온에서 소성시켜 에트린가이트와 잔류 화학혼화제 등을 분해시킨 후 사용하는 것이 우수한 것으로 나타났다.

콘크리트 구조물의 안전성 확보를 위한 콘크리트 품질 이력 관리시스템 구축

정진우,김용곤 한국안전학회 2021 한국안전학회지 Vol.36 No.6

Facility-related safety failures such as the collapse of 00 Bridge currently under construction and the determination of the lowest safety rating for a large-sized building in Gangnam continue to occur. In the ready-mixed concrete industry, illegal acts such as the use of unapproved cheap materials to cut back on the cost due to the growth slowdown in construction industry or reduction of cement volumes by deceiving the approved specific mix are being caught by police every year, leading to serious problems in concrete quality. To solve these problems, this study developed a structure traceability management system that inputs all the information including raw materials used for concrete, manufacturers, placing environments, and quality test result values in real time and manages them in a form of electronic document. To set up this system, a method of managing the present conditions from mixing design to placing was reflected through electronic documents. In order to secure reliability for concrete quality tests, a function that converts photographed test results into electronic documents using the mobile O.C.R (Optical Character Recognition) was developed, which is currently applied to 80 domestic construction sites in Korea. After the set-up, 9,735 mixing-design data and 10,025 quality test data have been stored as electronic documents in the 80 construction sites for 14 months. Additionally, the time to prepare documents according to the quality test was reduced by 74% from the previous 238 minutes to 62 minutes, proving the effectiveness in work efficiency. Data managed with these electronic documents will utilize a big data system and be helpful in identifying optimal mixing designs, structures, and structural forms of ready-mixed concrete by region. -

Investigation of Fiber Distribution in Concrete Batches Discharged from Ready-Mix Truck

Christian Sorensen,Egil Berge,Eirik B. Nikolaisen 한국콘크리트학회 2014 International Journal of Concrete Structures and M Vol.8 No.4

This paper presents the findings of an investigation of the fiber content variations in concrete being discharged from a ready-mix truck at the construction site. Concrete samples were extracted from the truck drums at the beginning, middle and end of discharge. Subsequently, fibers in each sample were separated from the concrete, and weighed. Presumably, synthetic macro fibers will float towards the top, i.e. towards the drum opening, of the inclined, revolving truck-drum, while, on the other hand, steel fibers will tend to gravitate towards the lower parts of the mixer drum. Accordingly, the discharge batch, containing synthetic macro fibers, will contain a higher amount of synthetic fibers per unit volume at the start of discharge than the average unit volume fiber content of the mix, and the content will gradually decrease further down the batch. The discharge batch of steel fiber concrete will contain fewer fibers per unit volume at the start of discharge than the average unit volume fiber content of the mix, and the content should gradually increase further down the batch. The correctness of the foregoing is partly confirmed. A certain percentage of the truck loads did not comply with the proposed requirements, mainly steel fiber reinforced batches, indicating the necessity of a code or guideline amendment. A change in the Norwegian shotcrete directive was made in 2011, based upon experimental research work (2010), which, in combination with the subsequent University of Life Sciences report (2012), constitutes the foundation of this article.

레디믹스트 콘크리트의 설계기준 압축강도별 염소이온 확산특성

박동천,김용로 한국건축시공학회 2018 한국건축시공학회지 Vol.18 No.6

The RC buildings which are constructed on the seaside are followed by KBC(2016) to achieve the minimization ofdurability damage. To control the corrosion of the reinforcing steel bar by salt attack, W/C should be under 0.4 andspecified concrete strength is higher than 35MPa in the concrete/building construction standard specification. Eventhough it has been proved that the concrete mixed with mineral admixture such as blast furnace slag and fly ash etc. have high strength and durability in previous researches, the beneficial informations are not applied to the codes. Ready-mixed concretes which usually include the admixtures in Busan were tested to certify the salt attack durability. In the same specified concrete strength, remarkable salt attack durability was evaluated in comparison to OPC. Foreconomical and reliable durability design, chloride ion diffusivity should be measured before applying to new buildingconstruction. 해안도시에 건설하는 건축물의 콘크리트 배합은 환경조건에 따라 설계기준 압축강도로 제한하고 있으나 혼화재혼입에 의해 염해 내구성이 급격히 향상되고 있음이 기존연구에서 명확히 되고 있으나 아직 규정에 반영되고 있지는못한 실정이다. 본 연구에서는 레미콘의 배합을 분석하고비교 시험체 제작을 통하여 염해 내구성에 대한 건축구조기준을 만족시키면서 경제성을 가지는 결과를 도출하고자 하였다. 시판되는 레미콘의 경우 설계기준 압축강도 이상의강도와 그에 따른 염소이온 차단성을 가지며 전 배합조건에대해서 OPC 35MPa를 능가하는 성능을 확인할 수 있었다. 내구성 및 경제성을 동시에 달성하기 위해서 납품 전 사전배합을 실시하여 염해 저항성을 포함한 기본물성을 검토할필요가 있다고 사료된다.