|Abstract: ||混凝土是一種由水泥、粗骨材、細骨材、水、波索蘭材料及化學附加劑等依比例拌合而成。它可依不同需求強度給予不同配比設，並於一定時間內依所需模型澆置、水化、凝固而成。也由於混凝土係多種原料之複合材料，因此材料品質之穩定性及施工品質良好與否對構造物之安全關係甚鉅。所以如何針對傳統混凝土材料及施工方法加以改進，避免泌水、析離或蜂窩現象，提升工程品質，有其迫切之需要。 有鑑於此，歐、美、日本等混凝土先進國家積極致力於混凝土技術研究，以期能大幅改進研究高品質之混凝土，並將以往易發生乾縮、潛變、龜裂、析離、泌水及工作性不佳等缺點一一改進，尤其鄰近台灣之日本自1980年起即引起業界高度重視，並於1986年提出靠混凝土自充填能力免搗實而能填滿入模之”自充填混凝土”觀念，同時也以其研究基礎理論研發了測試方法及試驗設備，緊接著國內”產、官、學”界經過多年通力合作推動下，也建立了一套自充填混凝土 ( SCC-Self Compacting Concrete ) 的遵循法則。此種混凝土澆置過程中不需施加外力振動搗實，完全藉由其本身流動之自充填性填充至鋼筋與鋼筋間與鋼筋與模板間之孔隙。而國內也在學術界、工程界及各方努力下，也於民國85年高雄國際廣場大廈的柱內灌漿應用了8000 psi強度之高性能混凝土，正式開啟並邁入了”高性能混凝土”實用階段。 現在自充填混凝土即將被廣泛應用於國道高速公路蘇花段，而本研究內容僅就其規範內之配比變化研究其膠結材料不同組合下之變化與應用及其對應於抗壓強度之關係及變化，同時對於所選用之骨材做一研究與建議，以期對SCC有更進一步認識與了解並改善。由研究結果顯示，SCC自充填混凝土最適膠結材料粉體量可依充填能例等級區分，如通過箱型試驗R1/R2障礙及無障礙者，其最低膠結材料粉體量應分別為500 kg/m³、450 kg/m³及400 kg/m³；而其膠結材料之最適組合經研究試驗顯示，同時採用水泥、爐石、飛灰非但可降低成本，降低水化熱，同時對於坍流度損失亦有正面之影響，唯結果顯示每立方SCC自充填混凝土其水泥用量至少應維持250 kg/m³以上，其它部份則將爐石與飛灰依80%：20% ~ 60%：40%之比例替代，如此即符合新世代混凝土基本架構”安全性、耐久性、工作性、經濟性及生態性”之訴求。|
Concrete is a mixing compound which consists of cement, coarse aggregate, fine aggregate, water, Portland material and other chemical additives. It allows itself to be designed in various recipes depending on different demands and can be set in a certain time to finish the process of grouting, hydrating and hardening. As concrete consists of many kinds of raw materials, the safety and quality of construction are greatly influenced by the stability of concrete. With that, how to improve the performance of concrete and construction method, i.e. avoid the bleeding, separation and honeycomb, etc, becomes a very important issue and imminent mission. In view of this, many countries like Europe, America and Japan make much effort to research and develop the technique of concrete. They anticipate to produce a good performance of concrete to improve the current shortage, such as dry-shrinkage, shift, crack, separation, bleeding, low efficient workability, etc. Since 1980, Japan started to pay high attention to this subject and in 1986 published an advanced idea of self compacting concrete (SCC) which can compact itself to the mould other than the traditional method using vibration. Based on this theory, they developed some special test methods and equipment. After years of effort contributed by “Industry, Government, Academy”, a complete set of systems and norms for SCC have finally been established. The main character of SCC is it is self-compacting when grouting. It needs no vibration and can self flow and fill the joint between steel and steel or steel and slate. This renovation leads Asia to a new era of concrete. Domestically, we also adopted this know-how to 8000 psi of high strength performance concrete for the grouting project in Kaohsiung Square Plaza in 1996. It was the first time to bring the theory to practice in Taiwan. Generally speaking, SCC (Self-Compacting Concrete) belongs to a kind of HPC (High-Performance Concrete). The only difference for SCC is it is self compacting without vibration. Nowadays, SCC is going to be applied to the SU-HWA section of the freeway. This study is to discuss the different mixing designs, the changes of hydra-heating and the relation of heat stress and compressive strength. We anticipate to have a further understanding and improvement to SCC. Study result indicates SCC binding materials can be classified by its compacting ratio. For instance, to pass the boxing test of R1/R2 within and without hindrance, the minimum binding materials should be 500kg/m3, 450kg/m3 and 400kg/m3. The optimum binding materials research shows if use cement, slag and fly-ash at the same time , it can reduce cost and the heat of hydration. Besides, it has a positive effect on slump loss. However, the research reveals that the dosage of cement for SCC should be above 250kg/m3 at least. As to the rest, they can be used slag and fly-ash by the ratio between 80%:20% ~ 60%:40% as substitution. Thus, the SCC binding materials’ concept will meet the requirement of “Safety, Durability,Workability and Ecology” for the new era.