高性能水中自充填混凝土

Abstract

水中結構物因為先天的位置限制，混凝土在澆置後難以控制與檢測其施工品質，僅能依賴正確的施工方法與優良的混凝土配比來確保品質。在90年代起工程界開始注重耐震設計，鋼筋用量增加導致間隙越來越密，傳統水中混凝土與高流動性水中混凝土的工作度與水中性能已不符合需求，而擁有SCC性能且遇水不分散的高性能水中自充填混凝土即為最適合的水中施工材料。 本研究以擁有自充填性能與水中不分散為導向，使用新的抗沖蝕摻劑與添加高強度混和材，開發出數種拌和時間縮減且強度優於以往的高性能水中自充填混凝土配比，並且測試新拌混凝土之工作性能以及硬固後混凝土一系列之力學試驗，確保其優良品質。期望藉著水中自充填混凝土的優良性質再配合特密管水中澆置，使得將來水中結構物的施工可更安全、快速、有效、且兼具環保。

It is very difficult to assure the quality of underwater construction. Usually it relies on the skilled worker and an estimated reduction on the strength. Since the 921 earthquake, the design earthquake force has been increased and the amount of steel reinforcement is also increased. This leads to a higher reinforcement ratio and small gap among steel rebars. The traditional concrete for underwater construction needs a change. The concrete posses the ability of both self-compacting and anti-washout is the concrete which can meet the stringent requirements of modern construction. This study develops the concrete which has the self-compacting capability and anti-washout, non-dispersive in water, and high strength. This concrete is then subjected to mechanical tests to make sure its suitability for field use. This concrete may be used with tremie pipe so that the underwater structures can be more reliable, safer, more efficient in construction, and durable.