石膠泥瀝青混凝土壓力式動態試驗系統研究與成效評估

石膠泥瀝青混凝土(SMA)因在承受車輛載重時，瀝青混凝土材料之自然圍束應力形成粗粒料間之互嵌效應而使其擁有較密級配優異之抗車轍破壞的能力。而以張應變破壞型態之評估試驗方法似乎不能顯示出SMA之特性，且一般所使用之壓力式評估試驗使用於SMA亦有其限制。故本研究針對SMA之力學性質與受力機制而發展瀝青混凝土版動態潛變試驗，並進一步以此系統進行瀝青混凝土版壓力式動彈模數試驗初步研究。由瀝青混凝土版動態潛變試驗之結果，本試驗的確能表現出SMA高抗永久變形之特性，證明以瀝青混凝土材料自然圍束應力來發揮其粗粒料間之互嵌效應之試驗條件是表現SMA力學特性之重要關鍵，而且本套試驗亦適合用來評估密級配之抗永久變形能力。從改變試驗溫度與荷重應力進行試驗之結果，發現不但SMA較密級配瀝青混凝土具更佳之抗變形能力，同時在永久變形方面，SMA對溫度與荷重應力之敏感性皆較密級配瀝青混凝土為小。若將潛變試驗之結果以Power Law法進行分析其回歸係數相當高，故能由回歸分析預估瀝青混凝土永久變形量之發展。由瀝青混凝土版壓力式動彈模數初步研究結果，得知當加壓平板直徑縮小，所得到之數值變化會漸趨於平緩而接近真正之彈性模數；而進行動彈模數試驗時不宜使用太大荷重應力以免造成太大之塑性變形。並且壓力式與間接張力式試驗所得之動彈模數其隨不同溫度、不同級配、不同瀝青膠泥而造成數值變化之趨勢無明顯不同。此針對SMA所發展出之壓力式動態試驗系統研究中，瀝青混凝土版動態潛變試驗確能表現SMA特性並且能評估SMA於不同試驗控制條件下的性質，故希望未來SMA之標準評估試驗方法能參考本研究之模式進行設計。然而瀝青混凝土版壓力式動彈模數僅為初步研究，不過由初步研究成果顯示此研究的確有可行性，並且具進一步探討開發之價值。

關鍵字

瀝青混凝土版壓力式動彈模數試驗；瀝青混凝土版動態潛變試驗；石膠泥瀝青混凝土(SMA) ；自然圍束應力

並列摘要

Stone Mastic Asphalt（SMA）has greater rut-resisting ability than DGAC when applying loading, because of the interlock effect between the coarse grains formed by natural confining pressure. To estimate only by tests under tensile failure model is not able to demonstrate the behavior of SMA. Besides, the ordinary tests have restrictions when performed on SMA. Therefore, this research develops a more suitable AC slab dynamic creep test particularly for the behavior and the mechanism of SMA. Furthermore, it carries out the initial research of compressive dynamic elastic modulus test of AC slab by this testing system. The result of AC slab dynamic creep test certainly can show the great ability of resisting permanent deformation. And it subsequently proves the testing condition of the natural confining pressure inducing interlock effect between coarse grains of AC material, is the key to demonstrate the mechanical behavior, and this test is also suitable to estimate the ability of resisting permanent deformation of DGAC. The results of the test under various temperature and loading, leads to the following conclusion: SMA not only has greater deformation-resisting ability than DGAC, meanwhile, it also has finer sensibility in permanent deformation. Analyzing the dynamic creep test data by Power Law Method would get a considerably large regression coefficient; hence it can estimate the permanent deformation development of AC from regression analysis. From the initial study of compressive dynamic elastic modulus test of AC slab, the data variation would gradually tend to be smooth, and approaches the actual elastic modulus, as the diameter of the plate decreases. To prevent the occurrence of large plastic deformation, the loading shouldn’t be too heavy when performing the dynamic elastic modulus test of the slab. Moreover, the variation tendencies of dynamic elastic modulus in compression test and indirect tension test have no obvious differences with different temperature, grading, or asphalt cement. In the study of compressive dynamic elastic modulus test of AC slab system of SMA, the AC slab dynamic creep test can indeed demonstrate the behavior of SMA, and moreover to estimate the behavior of SMA controlled by different testing condition. And hopefully the pattern in the research would be used as reference for design in the future standard estimating tests. Although the compressive dynamic elastic modulus of AC slab is just the initial research and the results show that it does have the feasibility and needs further study.

並列關鍵字

Compressive dynamic elastic modulus test of AC s ； AC slab dynamic creep test ； Natural confining pressure ； Stone Mastic Asphalt（SMA)

參考文獻

【35】 “Standard Method of Test for Resilient Modulus of Subgrade Soils and Untreated Base/Subbase Materials” AASHTO DESIGNATION T 292-91.

【21】 Freddy L. Robert, Prithvi S. Kandhal, E. Ray Brown, Dah-Yinn Lee, Thomas W. Kennedy, “Hot Mix Asphalt Materials Mixture Design and Construction” NAPA Education Fundation, 1991.

【22】 Hani A. Lotfi, Charles W. Schwartz, and Matthew W. Witczak. “Compaction Specification for the Control of Pavement Subgrade Rutting”, TRR, pp.108,198, 1996.

參考文獻