Relating Dynamic Shear Modulus (G*) of Performance Grade (PG) Asphalt Binders to Nanoindentation Stiffness (E)
项目名称: Relating Dynamic Shear Modulus (G*) of Performance Grade (PG) Asphalt Binders to Nanoindentation Stiffness (E)
摘要: Asphalt concrete's dynamic modulus (E*) is one of the key input parameters for structural design of asphalt/flexible pavements according to the new Pavement Mechanistic Empirical (ME) Design software. This software uses asphalt binder shear modulus, G*-based equation to estimate E* of asphalt concrete (AC) from mix volumetric information and binder properties. Use of shear modulus, G* of liquid asphalt to estimate E* of solid asphalt concrete (AC) sample is not justified and has been questioned by asphalt researchers for long time. Because liquid binder is not a part of AC, rather thin film of asphalt binder, mastic, and aggregate are the parts of a solid AC sample. Not only that, AC's E* testing is performed in uniaxial compression mode, whereas asphalt binder's G* test is performed in shear mode. Due to equipment and discovery limitations, over the past years, asphalt industry has performed asphalt binder tests that are limited to rheology and bulk volume of liquid. Asphalt industry has not come up yet with equipment and/or method that can be used on binder film or mastic or aggregate phase of a solid AC sample. Recently, nanoindentation has created an opportunity to determine the stiffness (E) of asphalt binder, mastic, and other phases while they are being integral parts of an AC sample and also, under compression (indentation) loading. This project proposes to conduct dynamic shear modulus (G*) and nanoindentation stiffness (E) testing of selected performance grade (PG) asphalt binders, examine possible correlation between G* and E, and possibly replace the existing G*-based equation with E-based equation for pavement design. This proposed study may dramatically improve the way our asphalt pavements being designed using the new Pavement ME Design software.
状态: Completed
资金: 152000.00
资助组织: Department of Transportation
开始时间: 20140910
预计完成日期: 20150909
实际结束时间: 20160930
主题领域: Design;Highways;Pavements
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