- 學位論文
溫拌再生瀝青混凝土水分侵害特性之研究
Evaluation of Moisture Damage on Warm Mix Asphalt with Reclaimed Asphalt Pavement Material
摘要
再生瀝青混凝土之刨除料（reclaimed asphalt pavement, RAP）回收再利用不僅能解決國內天然砂石資源枯竭、舊路面刨除廢土棄置等問題，還可減少新鮮粒料與瀝青膠泥之使用，大量降低生產業者之生產成本。且國內基礎交通道路面積約97%以上為瀝青混凝土鋪面，回收價值相當可觀。但是再生瀝青混凝土之刨除料使用量卻須避免製作過程中，老舊瀝青膠泥因高溫過度老化而將有所限制。溫拌瀝青混凝土（warm mix asphalt, WMA）除了兼具環保與節能等特性，並且能有效降低瀝青混凝土之拌合溫度，減低材料過度老化產生之風險，以提高刨除料可能之使用量。 水分侵害又稱之為剝脫，為瀝青混凝土鋪面常見的破壞形式之一。台灣位處亞熱帶地區，夏季高溫潮濕多雨，加上溫拌瀝青混凝土技術低溫製程之特性，勢必將殘留較多之水分於粒料表面，進而提升水分侵害產生之潛在威脅。本研究旨在探討溫拌處理技術用於再生瀝青混凝土時，抵抗水分侵害特性之差異，以供日後鋪面工程應用之參考。研究中採用兩種溫拌添加劑Sasobit® H8與Rediset® WMX，並分別添加至0%、35% 及70%三種刨除料取代量之再生瀝青混凝土中，利用試驗室水分侵害試驗檢驗其剝脫性質。 研究結果顯示溫拌添加劑 Rediset® WMX相較於Sasobit® H8更能有效降低瀝青混凝土所需之拌合溫度，各項水分侵害試驗結果之表現亦優於 Sasobit® H8，說明Rediset® WMX兼具溫拌處理與防剝之效果。然而就剝脫性質而言，Sasobit® H8之添加與否並無顯著差異，其表現甚至略遜於傳統熱拌瀝青混凝土。研究顯示，於改良式羅特曼試驗中，當再生瀝青混凝土之刨除料含量達70%時，試驗結果並不符合規範要求，若添加Rediset® WMX則將可提升試驗結果至合格標準，說明即使於高刨除料使用量下，Rediset® WMX仍可避免溫拌低溫條件之不良影響並有效改善溫拌再生瀝青混凝土抵抗水分侵害之能力。
並列摘要
The use of reclaimed asphalt pavement (RAP) helps saving natural resources and money. More than ninety-seven percent of the roads surface in Taiwan is paved with hot-mix asphalt (HMA). Recycling of RAP is a crucial necessity to save precious nature aggregates, and reduce the use of costly asphalt binder. But the higher production temperature limits the amount of RAP. To avoid deterioration of the aged binder, RAP should not be exposed to too high temperatures. The introduction of warm-mix asphalt (WMA) technologies, however, provides the opportunity to mix and compact asphalt mixtures at a lower than conventional temperature, and hence could increase the percentage of RAP usage to save more energy and natural resources. Moisture susceptibility of mixtures, generally called stripping, is a major form of distress in asphalt concrete pavements. High temperature, humidity and massive rainfall in summer characterize the climate in Taiwan. Moisture susceptibility of recycled HMA with warm mix asphalt technologies may be a critical problem due to incompletely dried aggregates resulting from its lower mixing and compacting temperature, especially in Taiwan’s climate. This study investigated the effects of WMA additives on moisture susceptibility of recycled HMA containing RAP by using several major stripping tests. Results from our laboratory study indicated that the use of Rediset® WMX provided better performance in reducing mixing temperature and stripping resistance, compared to Sasobit® H8. No significant difference was found between moisture susceptibility with and without Sasobit® H8. The results of stripping tests showed that Rediset® WMX did have good performance in resisting moisture damage even with 70% of RAP. The use of Rediset® WMX in recycled HMA to increase RAP content at a lower mixing and compacting temperature seemed feasible based on the results of our study.