Interaction nonlinearity in asphalt binders
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- 作者：Arash Motamed (1) motamed@utexas.edu
Amit Bhasin (1) a-bhasin@mail.utexas.edu
Kenneth M. Liechti (2) kml@mail.utexas.edu - 关键词：Asphalt binder – ; Dynamic shear rheometer – ; DSR – ; Pavement – ; Viscoelastic – ; Interaction – ; Nonlinear – ; Normal stress
- 刊名：Mechanics of Time-Dependent Materials
- 出版时间：May 2012
- 出版年：2012
- 期刊代码：85_13852000
- 类别：med
- 卷：16
- 期：2
- 页码：145-167
- 数据来源：sp
摘要
Asphalt mixtures are complex composites that comprise aggregate, asphalt binder, and air. Several research studies have shown that the mechanical behavior of the asphalt mixture is strongly influenced by the matrix, i.e. the asphalt binder. Characterization and a thorough understanding of the binder behavior is the first and crucial step towards developing an accurate constitutive model for the composite. Accurate constitutive models for the constituent materials are critical to ensure accurate performance predictions at a material and structural level using micromechanics. This paper presents the findings from a systematic investigation into the nature of the linear and nonlinear response of asphalt binders subjected to different types of loading using the Dynamic Shear Rheometer (DSR). Laboratory test data show that a compressive normal force is generated in an axially constrained specimen subjected to torsional shear. This paper investigates the source of this normal force and demonstrates that the asphalt binder can dilate when subjected to shear loads. This paper also presents the findings from a study conducted to investigate the source of the nonlinearity in the asphalt binder. Test results demonstrate that the application of cyclic shear loads results in the development of a normal force and a concomitant reduction in the dynamic shear modulus. This form of nonlinear response is referred to as an “interaction nonlinearity”. A combination of experimental and analytical tools is used to demonstrate and verify the presence of this interaction nonlinearity in asphalt binders. The findings from this study highlight the importance of modeling the mechanical behavior of asphalt binders based on the overall stress state of the material.