| 摘要: | 瀝青材料在柔性路面工程的主要用途為黏結粒料作為瀝青路面之面層或底層處理，以承受車輛之荷重，確保行車之舒適與平順。公路總局瀝青混凝土所使用之瀝青材料，長期以來皆使用黏度級AC-10（針入度85?100）瀝青膠泥，而國內之年平均氣溫依中央氣象局統計資料顯示，平地部分超過20℃，南部地區甚至超過24℃，對於使用AC-10瀝青膠泥似有過軟，部分工程單位亦反應，夏天容易產生瀝青混凝土軟化而造成車轍或冒油現象。以國內之氣候條件，應可選擇黏度級AC-20之瀝青膠泥供鋪築路面材料使用。 經公路總局函示第三及第五養護工程處（南部地區）各擇一工程辦理試鋪AC-20，並由材料試驗所配合辦理試鋪路面成效評估，本研究為第三區工程處之試鋪路段評估結果。第三區工程處以省道1號線380k+000至381k+596(北上雙車道)辦理試鋪，試鋪路段為（1）380k+000~380k+448，長448m加封5cm厚AC-10密級配瀝青混凝土作為對照組-1，（2）380k +448~381k+000，長552m加封5cm厚AC-20密級配瀝青混凝土作為試驗組，（3）381k+000~381k+596，長596m加封5cm厚AC-10密級配瀝青混凝土作為對照組-2。試驗路段共分為三個試驗區（北上單側）。 評估試驗項目包括瀝青混凝土路面空隙率變化、馬歇爾穩定值變化、撓度、車轍調查、縱斷面指數(PrI)、3m高低平坦儀、路況調查等七項，分6期第1年每期3個月；第2年每期6個月觀測乙次，共追蹤觀測2年。 本研究經各項試驗之分析結果作初步結論：除路面結構強度，AC-20有較佳表現，統計上有非常顯著差異外，其餘功能AC-20亦不亞於AC-10，由此顯見AC-20應可全面應用於公路總局所轄路面工程瀝青材料使用。因為評估期尚短（2年），兩種材質路面均未達破壞時機，其耐久性及部分功能尚無法顯現，俟公路總局大量使用AC-20為瀝青材料，並累積相當施工經驗後，必能提昇道路之服務水準，且贏得社會大眾的掌聲。 Hot-mix asphalt (HMA) has two primary ingredients: binder and aggregate. The asphalt binder is usually asphalt cement. The mix design system determines the correct proportion of asphalt cement and aggregate needed to produce an asphalt mix that has the properties and the characteristics to withstand the effects of traffic and the environment for many years. Viscosity graded asphalt cement AC-10 has been used in HMA binder by Directorate General of Highway, Ministry of Transportation and Communications (MOTC) for many years. During Summers, there are some ruts?bleeding and fat spots in the pavements. AC-10 material seems to be softer, less viscous for HMA binder in pavement constructions. Climate can have a major impact on mix and pavement performance for a given pavement structure. The mean annual air temperature is from 22.3℃ to 25.0℃ in Taiwan. According to the Asphalt Institute Manual Series No. 2 (AI MS-2), AC-20(penetration graded asphalt cement 60-70 grade) material will be chosen for HMA binder in such hot climate like Taiwan. In order to practice the new HMA binder such like AC-20, Directorate General of Highway, (MOTC) chooses No.1 Provincial Road 380k+000~381k+596 to pave the AC-20. By the evaluation, there are 6 times laboratory and in-situ tests in 2 years by the Materials Testing Laboratory, Directorate General of Highway, (MOTC). Such as the percent air voids, stability, deflection(the Benkelman Beam), rutting, Hi-Lo detector, profilograph and distress survey. By the statistical testing of the results, there is an apparent difference in the strength of pavement structure between AC-10 and AC-20. In other words, AC-20 asphalt concrete pavement provides higher strength than AC-10 asphalt concrete pavement. It is a good strategy to choose AC-20 for HMA binder in Taiwan. Practice makes perfect. To sum up then, AC-20 asphalt concrete pavement can be widely put to use in Taiwan under management of Directorate General of Highway, (MOTC) and it is very helpful for Directorate General of Highway, (MOTC) to acquire favorable public impressions and raise highway construction quality up to pavement serviceability. |
