{"insert":{"user_id":"1000201354","type":"misc","id":"30447325"},"force":{"see_also":[{"@id":"https://web.db.tokushima-u.ac.jp/cgi-bin/edb_browse?EID=185810","label":"url"}],"paper_title":{"en":"Study on practical system for production and construction of high-performance concrete with help of visualization technique of fresh concrete","ja":"可視化実験手法を用いた高性能コンクリートの製造・施工システムの実用化に関する研究"},"authors":{"en":[{"name":"Hashimoto Chikanori"},{"name":"Mizuguchi Hiroyuki"},{"name":"Ueda Takao"},{"name":"Watanabe Takeshi"}],"ja":[{"name":"橋本 親典"},{"name":"水口 裕之"},{"name":"上田 隆雄"},{"name":"渡邉 健"}]},"description":{"en":"A purpose of this study is to develop the practical system for production and construction such as concrete mixer, concrete agitator and concrete pumping machine in order to spread the use of high performance concrete such as high strength concrete, high durable concrete or high-fluidity concrete. After carrying on the investigation, we decided to develop the high performance mixer for manufacturing high strength concrete having more than 100N/mm2 of compressive strength, high durable concrete having more than 200 years of life time or high-fluidity concrete with the self-compacting ability of Rank 1. The bi-axial forced-mixing type of kinds of the mixer is high and the mixing efficiency is the highest. The flow patterns of the bi-axial forced-mixing type mixer are divided into two: the locally crossing flow and the globally circulating flow. We have developed and proposed a visualization technique that makes it possible to measure the degree of mixing with lapse time. At first a model concrete was assumed to be a viscous model of one phase system for the model mixer of two types with different area of the locally crossing flow, the mixing efficiency curve of the model concrete of the high viscosity and the low viscosity was a process of becoming uniform with the axial rotation, and quantification was attempted. Secondly we tried the quantification of the crossing flow around the blade generated when two circulating flows crossed by the pressure fluctuation of the pressure sensor installed in the surface of the blade of the mixer was attempted, and the size of the crossing flow generated in the model mixer of two types and the correlation of the mixing efficiency curve were considered. Thirdly we developed the new bi-axial forced-mixing type mixer with oscillation of mixture and mix proportion design based on mix proportion of high strength concrete are carried out to investigate the possibility for increasing properties and durability of concrete incorporating low quality recycled aggregate. As the results of this study, the mixing method with oscillation of mixture has effect on the concrete using low quality recycled aggregate to increase about 20% of compressive strength.","ja":"本研究課題は，高性能コンクリートの普及を目的して，コンクリートミキサ，コンクリートアジテータならびにコンクリートポンプ等の製造・施工システムの高性能化を図ることである．調査の結果，コンクリートミキサの高性能化がもっとも現実的であり，経済的効果が高いこと，大都市での建設では，設計基準強度100N/mm2を超える超高強度コンクリート対応の高性能なミキサが必要不可欠であることなどの理由から，コンクリートミキサの開発に絞ることにした．その結果，2軸強制練りミキサに振動付与装置を取り付けた新しい構造のミキサの実用化を行った．初年度は，1相系の可視化モデルコンクリートを用いて，2軸のブレードの回転によって形成されるらせん流動が，相互に衝突しあう領域に形成される局部交錯流動の定量化を試みた．その結果，ミキサの容器形状(深さ，2軸間距離，軸長さ)が異なることによって，局部交錯流動の大きさ，特にせん断流によって形成される圧力の乱れが大きく変化することが明らかになった．2年目は，これらの知見を基に，試験練り用60 の2軸強制練りミキサを製作し，局部交錯流動の乱れを大きくするために，練り混ぜ途中に振動付与を与える機構を組合せた振動付与2軸強制練りミキサを開発した．吸水率が10%を超えるL級再生細・粗骨材を100%用いた再生骨材コンクリートと100N/mm2以上の高強度コンクリートを対象にして，その性能を評価した．最終年では，さらなるミキサの高性能化を図ることを目的とし，固液2相系の可視化モデルコンクリートを用いて，ブレード先端の圧力変動を計測した．主な着目点は，アーム遅れ角度がせん断流に及ぼす影響である．実験の結果，ミクロ的な練混ぜ性能が良好なミキサの条件としては，局部交錯部の領域が大きくかつ連続性を持つパドル配列を有するものであることが明らかになった．"},"publication_date":"2008-12","publication_name":{"en":"Reprot of research project (Scientific Research B ), grant-in-aid for scientifc research (Project number 17360205)","ja":"科学研究費補助金(基盤研究B)研究成果報告書(課題番号17360205)"},"misc_type":"others"},"priority":"input_data"}