• Title/Summary/Keyword: Recycled Powder

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An Experimental Study on the Rheology Characteristics of Insulating Concrete (단열콘크리트의 레올로지 특성에 관한 실험적 연구)

  • Ryu, Dong-Woo;Ji, Suk-Won;Jeon, Hyun-Kyu
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.2
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    • pp.118-124
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    • 2016
  • The purpose of this study is to analyze the rheology characteristics of insulating concrete for each type of insulation performance improvement material and utilize the result as preliminary data for optimal flow designing and pumping analysis. As a result, when lightweight aggregate was mixed, the yield stress decreased significantly, and in case of type 2, the combination of micro form cell admixture (MFA) and calcined diatomite powder (DM) showed the most ideal flow characteristics. In case of type 3, the combination of micro form cell admixture (MFA), calcined diatomite powder (DM) and lightweight aggregate (L) showed the best flow characteristics.

Effect of Incineration Plant Ash on Fundamental Properties of High Volume Blast Furnace-Slag Mortar incorporating Recycled Aggregate Powder (소각장애시의 치환률 변화에 따른 순환골재 미분말 함유 고로슬래그 다량치환 모르타르의 기초적 특성)

  • Huang, Jin-Guang;Park, Jae-Yong;Jung, Sang-Woon;Heo, Young-Sun;Han, Min Cheol;Han, Cheon Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.11a
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    • pp.126-127
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    • 2013
  • For the decades, various of materials were used to instead of cement as the high volume CO2 occurred during the process of cement manufacture. In this paper, incineration plant ash was used in the mortar which incorporating high volume of blast furnace slag. Water to binder ratio(W/B) is fixed as 50%,BS+RP's replacement ratio is fixed as 80%,and the replacement ratio of WA1 is range as 0,0.5,1,2,3,4,5%.For the fresh mortar, flow and chloride contents has been tested. For the hardened mortar, compressive strength at 3,7,28 days has been tested. the result shows that when the replacement ratio of WA1 is 0.5%,the chloride contents is less than 0,3 kg/m3,the flowability and strength also performed better than other replacement types of mortar.

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Development of FRP Recycling Process for Regenerating Applications of Fire Resistance Performance of High Strength Concrete (고강도 콘크리트의 내화성능 용도에 따른 FRP재활용 공정 개발)

  • Lee, Seung Hee;Park, Jong Won;Yoon, Koo Young
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.18 no.3
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    • pp.207-215
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    • 2015
  • In the last decade, increasing national research fund for recycling the waste FRP (fiber reinforced plastics) ships which has caused environmental problems, improves the technology making concrete-reinforcing fibers out of the waste FRP. Furthermore, the concrete with recycled FRP fiber was tested for the structural performance. Experimental strength tests show that use of recycled FRP powder does not reduce the compressive strength of high strength concrete, and does increase the fire resistance performance of high strength concrete significantly. But, the study in investigating the properties of recycled fiber powder from waste FRP has not been completed because of the absence of the method of separation of mat layer from the waste FRP. This study is to propose a new extracting method of the mat layer from waste FRP, which is the efficient and environment friendly system. and thus it is considered to be the useful recycling method for fire resistance high concrete products or structures.

Assessment of flowing ability of self-compacting mortars containing recycled glass powder

  • Alipour, Pedram;Namnevis, Maryam;Tahmouresi, Behzad;Mohseni, Ehsan;Tang, Waiching
    • Advances in concrete construction
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    • v.8 no.1
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    • pp.65-76
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    • 2019
  • This paper investigates the effect of recycled glass powder (RGP) on flowing properties of self-compacting mortars (SCMs) containing different ratios of fillers and superplasticizer dosages. Fly ash (FA), nano-silica (NS), micro-silica (MS), metakaolin (MK) and rice husk ash (RHA) are used as fillers and their synergistic effect with RFP is studied. The effects of fillers and high-range water reducer (HRWR) on flowing ability of mortars are primarily determined by slump flow and V-funnel flow time tests. The results showed that for composites with a higher RGP content, the mortar flowing ability increased but tended to decrease when the composites containing 10% MK or 5% RHA. However, the flowing ability of samples incorporating 5% RGP and 10% SF or 25% FA showed an opposite result that their slump flow spread decreased and then increased with increasing RGP content. For specimens with 3% NS, the influence of RGP content on flowing properties was not significant. Except RHA and MS, the fillers studied in this paper could reduce the dosage of HRWR required for achieving the same followability. Also, the mixture parameters were determined and indicated that the flowability of mixtures was also affected by the content of sand and specific surface area of cement materials. It is believed that excess fine particles provided ball-bearing effect, which could facilitate the movement of coarse particles and alleviate the interlocking action among particles. Also, it can be concluded that using fillers in conjunction with RGP as cementitious materials can reduce the material costs of SCM significantly.

Analysis of the Sedimentation Status Test for Type-3 Dry Chemical Powder with Changes in Internal Pressure of the Dry Chemical Extinguisher (분말소화기의 내부압력 변화에 따른 제3종 분말소화약제의 침강도 시험)

  • Ju-Dal Son;Seo-Young Kim;Ha-Sung Kong
    • Journal of the Korea Safety Management & Science
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    • v.25 no.1
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    • pp.67-74
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    • 2023
  • This study aims to measure sedimentation status change with the changes in internal pressure for dry chemical extinguishers of various use periods and analyze the suitability of the fire extinguishers' performance criteria. When the internal pressure of the fire extinguisher is 0%, 2 out of 10 new dry chemical powders for the 5 elapsed years were noted to be suitable, including 3 recycled dry chemical powders with 5 elapsed years that were found eligible. One out of 10 new dry chemical powders for 10 elapsed years was shown as suitable. Also, one new dry chemical powder for 13 elapsed years was suitable. When the internal pressure of the fire extinguisher was 50%, all 10 out of 10 new dry chemical powders for 5 years, recycled one with 5 elapsed years, and a new one with 10 elapsed years were found to be suitable, while 9 new dry chemical powders for 13 years were shown as suitable. When the internal pressure of the fire extinguisher was normal, new ones with 5 elapsed years, recycled ones with 5 elapsed years, new ones with 10 elapsed years, and new ones with 13 elapsed years were all 10 out of 10 samples noted as suitable. In summarizing the experiment results, it was found that the sedimentation status, one of the fire extinguisher's physical properties experiments, affects the fire extinguisher's performance criteria rather than the change with use periods.

Evaluation on the Mechanical Performance of Low-Quality Recycled Aggregate Through Interface Enhancement Between Cement Matrix and Coarse Aggregate by Surface Modification Technology

  • Choi, Heesup;Choi, Hyeonggil;Lim, Myungkwan;Inoue, Masumi;Kitagaki, Ryoma;Noguchi, Takafumi
    • International Journal of Concrete Structures and Materials
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    • v.10 no.1
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    • pp.87-97
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    • 2016
  • In this study, a quantitative review was performed on the mechanical performance, permeation resistance of concrete, and durability of surface-modified coarse aggregates (SMCA) produced using low-quality recycled coarse aggregates, the surface of which was modified using a fine inorganic powder. The shear bond strength was first measured experimentally and the interface between the SMCA and the cement matrix was observed with field-emission scanning electron microscopy. The results showed that a reinforcement of the interfacial transition zone (ITZ), a weak part of the concrete, by coating the surface of the original coarse aggregate with surface-modification material, can help suppress the occurrence of microcracks and improve the mechanical performance of the aggregate. Also, the use of low-quality recycled coarse aggregates, the surfaces of which were modified using inorganic materials, resulted in improved strength, permeability, and durability of concrete. These results are thought to be due to the enhanced adhesion between the recycled coarse aggregates and the cement matrix, which resulted from the improved ITZ in the interface between a coarse aggregate and the cement matrix.

Analysis of Strength Characteristics for Lightweight Soils Using Recycled Material (폐기물을 첨가한 경량혼합토의 강도특성 분석)

  • Bae, Yoon-Shin
    • Journal of the Society of Disaster Information
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    • v.8 no.3
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    • pp.204-212
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    • 2012
  • Lightweight soils are very economical and environment friendly materials that are valuable in field without wasting construction materials, dredged soils and clay/ silty soils during construction. Recently, the research of lightweight soils mixed with recycled material (recycled tire powder, rice husks) have been investigated. In this study the mix design factors (i.e., weight of soil, water content, foaming agent and added water) were analyzed and optimized mix design was suggested using cement content for revealing strength. For the analysis the stress-strain behavior, strength with respect to time, and experimental strength for the component of recycled material were analyzed. Finally, target strength was determined to calculate reasonable and economical mix ratio and the optimized cement content was suggested.

Compressive Strength Characteristics of Non-Cement Composition Added with Limestone Powder (석회석미분말이 첨가된 비시멘트 조성물의 압축강도 특성)

  • Kim, Young-Min;Jung, Jae-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.178-179
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    • 2019
  • The cement industry is a large amount of carbon dioxide emission industry, and research and development on non-cement composition is underway at the time when the absolute reduction of cement use is urgently needed. In addition, limestone fine powder is a by-product and is required to be recycled in terms of resource circulation. The compressive strength of the lime cement powder added noncement composition showed that the compressive strength increased as the limestone powder was added. It is believed that limestone fine powder played a role of stimulant such as alkali activator in non-cement composition.

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Application of the tuned prediction algorithms on recycled powder mortar from construction and demolition debris

  • Qiao Yuan;Liu Yang;Zhou Yang;Wang Runlong;Liu Tiegang
    • Computers and Concrete
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    • v.34 no.6
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    • pp.773-789
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    • 2024
  • Recycled powder (RP) has emerged as a promising and viable alternative to traditional cementitious materials for use in concrete. The compressive strength (fC) of RP mortar has a considerable impact on the mechanical properties of RP concrete. Utilizing machine learning approaches to engineering problems, particularly when estimating the mechanical properties of construction materials, results in outstanding accuracy in forecasting and minimal experimental costs. This study aimed to provide some integrated machine-learning techniques for estimating the fC of recycled powder mortar (RPM). Initially, relevant literature is consulted to acquire data on the fC test results of 204 groups of mortars. Subsequently, the Extreme Gradient Boosting (XGB), Random Forest (RF), and Support Vector Regression (SVR) methodologies are used, followed by the optimization of their respective hyperparameters using the Chimp optimization algorithm (ChOA), in order to construct powerful forecasting approaches (XGBChOA, RFChOA and SVRChOA). According to the results, all three models exhibit excellent results in correctly anticipating the fC. By leveraging these advanced machines learning techniques and optimizing them with ChOA, the authors intended to achieve high accuracy in their predictions, thereby reducing the need for extensive experimental testing and minimizing costs associated with traditional methods of estimating the mechanical properties of construction materials. By accurately predicting the fC of RPM, these models can significantly reduce the need for extensive physical testing, leading to cost savings in material research and development. While the study mentions the generalization ability of the models, it would be beneficial to assess their performance on independent datasets or in real-world applications to confirm their practical utility. Including external factors or environmental conditions factors in the analysis could enhance the model's accuracy and robustness. The SI results of the models are roughly identical, with a small superiority of XGBChOA (SITrain=0.0334 and SITest=0.0567) compared to RFChOA, but remarkably better than SVRChOA. As it was clear from OBJ that the lowest value of OBJ belonged to XGBChOA at 1.2597, followed by RFChOA by 1.6792, and then SVRChOA equals to 1.3769.

Effect of the Replacement Ratio and Sources of Blast Furnace Slag Powder on the Fundamental Properties of Recycled Fine Aggregates Based Mortar (고로슬래그 미분말의 산지 및 치환율 변화가 순환잔골재 사용 시멘트 모르타르의 특성에 미치는 영향)

  • Han, Cheon-Goo;Zhao, Yang
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.3
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    • pp.257-263
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    • 2015
  • In this study, the quality of blast furnace slag and the engineering properties of recycled aggregate based mortar with variable replacement of blast furnace slag have been focused. Blast furnace slag(BS) manufactured in various areas in Korea were prepared for this study. For the investigation results, 4 types(among the all of 9 types) of the experimental results were identified as below the standard level when using blast furnace slag chosen from different factories. Especially the particle size of the blast furnace slag was considered as the largest problem. When using BS in the recycled aggregates based mortar, the increase amount of blast furnace slag, increased the fluidity but delayed the setting time and decreased strength at early age. Based on the relationship of the amount of BS and the engineering properties of mortar, this study found that the amount of SO3 and L.O.I affect the setting time, 3 days strength and 91 days strength to the certain standard level.