水中自充填混凝土應用探討

Abstract

目前工程界進行之水中結構物，主要以連續壁、深基礎樁為主， 仍然使用傳統混凝土或高流動性混凝土，其澆置品質並不容易控制。 經過多年研發，已成功研發擁有自充填特性、遇水不析離的水中自充 填混凝土，藉著本身之重量，不需要搗實、振動即可通過鋼筋間隙， 並充填至模板各個角落，避免發生混凝土施工品質不良之缺陷。 本研究以自充填特性、水中不析離及抗沖蝕能力為試驗目標，測 試新拌混凝土：工作度、水中L 型流度、濁度值、pH 值、抗沖蝕試 驗。為了真實模擬現地施工，在水中使用特密管工法澆置試體，比較 空氣澆置與水中澆置對混凝土的真實差異。本研究也將水中自充填混 凝土推廣到國內工程應用，比較水中自充填混凝土和傳統水中混凝土 之差異，包含抗壓強度、工作度、水中不析離試驗、完整性檢測，為 了探討基樁內部填充情形，於鋼筋籠周圍裝置8 支透明管，以利攝影 機進入基樁內部觀察混凝土澆置過程與硬固後的情形。經過試驗證實 水中自充填混凝土能達到自充填的特性且遇水不分散，水中澆置的抗 壓強度可達空氣澆置的90%、L 流度12 秒達到50cm 且水質清澈、 基樁攝影可以看到樁底淤泥向上抬升、完整性檢測沒有發現缺陷。證 實水中自充填混凝土能有效改善國內工程品質。

Currently carried out in the water engineering structures, mainly in a continuous wall, the main deep foundation pile, still use traditional concrete or concrete with high fluidity, its not easy to control the placement of quality. After years of research and development, has successfully developed self-compacting concrete for underwater construction and contacted with water will not spread. Self-compacting concrete (SCC) is a concrete which can fill into every corner of the form by its own weight without vibration . Effectively improve the poor quality of concrete construction defects This research develops this underwater SCC which will not segregate in water and have excellent workability and is anti-washout in water. The indices for the performance include pH values, turbidity value, anti-washout ability, and workability. In order to simulate the actual construction in the water, using tremie to pour concrete mold. In the air and water environment, compare two environmental impact on the concrete. Underwater self-compacting concrete applied to domestic engineering in this study, including compressive strength, workability, the water is not tested for in vitro analysis, non-destructive testing. In order to fill the case of internal piles, the steel cage around the transparent tube device 8, to facilitate observation of the camera into the pile of concrete placement of the internal process and the situation after hardened concrete. Keywords: underwater self-compacting concrete, antiwashout,tremie