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標題: 輕質骨材自充填混凝土之性質研究
Properties of self-compacting lightweight concrete
作者: 陳胤成
關鍵字: 輕質骨材
出版社: 土木工程學系
摘要: 自充填混凝土擁有高流動性及能保持骨材不析離,對於施工技術有很大之貢獻。目前自充填混凝土所使用之常重骨材來源受限,對於未來使用上將有所阻礙,但已有學者利用台灣水庫淤泥成功燒製成輕質骨材,所以本研究利用輕質骨材取代自充填混凝土中常重骨材,討論其新拌及硬固性質之差異性。雖然輕質骨材的單位重較低,重量比水泥砂漿輕,不利於靠自重增加充填效果,但相對地也克服常重骨材易析離及沈底的缺點。本研究即為以輕質骨材取代常重骨材之輕質骨材自充填混凝土(SCLC),並適當放大輕質骨材在混凝土中所佔之比例,來探討輕質骨材在自充填要求下可能的最大使用量。 試驗結果顯示,藉由輕質骨材吸水量及視黏滯度之控制下,坍流度達600~700mm,箱型試驗充填高度達300mm,即可達到自充填效果。在輕質骨材相同體積取代常重骨材之新拌性質,無論是坍流度、箱型及V型皆優於常重混凝土。而硬固性質皆可逹到一般之基本要求,且其均勻性亦能符合規定。 輕質骨材自充填混凝土因單位重較小,故其流動性較慢,V型試驗時間仍較規範規定增加約5至10秒,充填試驗之混凝土充填的時間亦會拉長約20秒,且其充填高度亦較低約50mm左右,其坍流度超過700mm時,將有骨材上浮析離之潛在危機。
Self-compacting concrete (SCC) owns excellent workability and is able to keep the aggregate from separating. It is a great contribution for construction technology. However, the natural aggregate with limited resource has become an obstacle to popularize SCC in the future. Therefore, lightweight aggregates were used in this research to replace the naturals in SCC as the self-compacting lightweight concrete (SCLC). The difference in fresh and harden concrete between SCC and SCLC were discussed. The unit-weight of lightweight aggregate is less than the naturals but heavier than the mortar. It is disadvantageous to improve the compacted effect, but overcomes the defects of SCC with aggregate easily separating and sinking. The proportion of coarse aggregate in concrete is increased appropriately for conforming to the request of self-compacting concrete. The experimental results show that the SCLC can be produced successfully when the slump-flow reaches 600 mm to 700 mm and the height of U-test reaches 300 mm by controlling water absorption of lightweight aggregate and the viscosity coefficient of mortar. No matter slump-flow, U-test and V-funnel test, SCLC is better than SCC under the same aggregate volume in concrete. The properties of harden concrete can fit in with the general requests, and uniform test result matches the request of code, too. Because of the less self-weight, SCLC has slower flowing process. The time through V-funnel increases about 5 sec to 10 sec, the duration of U-test extends about 20 seconds and the height of U-test reduces about 50 mm. When the slump-flow is over 700 mm, there will be a potential crisis of aggregate separating.
Appears in Collections:土木工程學系所



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