Journal of Transportation Engineering · 2004 · 213 citations · 8 references
Repeated loading of crushed rock aggregate causes permanent deformation that is compared with conventional shakedown responses. The study introduces a modified shakedown response set and uses the elastic shakedown limit to predict stable behavior or rutting in pavement granular layers. The elastic shakedown limit of Granodiorite is applied to dimension pavement granular bases and its design is compared to an empirical German procedure. Triaxial tests show that the conventional shakedown approach only partially captures observed responses, while the new elastic shakedown limit approach demonstrates benefits and limitations when benchmarked against the German design.
The paper reports the results of several repeated load triaxial tests performed on a crushed rock aggregate at different stress levels. The development of the resulting permanent deformation that accumulates with the repeated loading is described and compared with the types of responses usually described by the shakedown approach. It is shown that the existing shakedown approach can describe some, but not all, of the observed responses. Thus a modified set of possible responses is defined in shakedown terms and some explanations of the differences from the conventional approach are given. The elastic shakedown limit can be used to predict whether or not stable behavior occurs in the unbound granular material layer of a pavement construction or whether rutting will occur. With this information a pavement's granular base may be dimensioned. The elastic shakedown limit of a Granodiorite has been used in this manner and the resulting design compared with an empirical German design procedure. The paper concludes with an assessment of the benefits and limitations of the new approach.
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