Date of Graduation

5-2015

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Degree Level

Graduate

Department

Civil Engineering

Advisor

Andrew Braham

Committee Member

Kevin Hall

Second Committee Member

Michelle Bernhardt

Abstract

While Full Depth Reclamation (FDR) has many potential cost and environmental benefits, especially over the lifetime of the pavement, it is necessary to be able to ensure that the recycled pavement will perform adequately. One way in which this can be accomplished is understanding how to best complete the structural design of FDR pavements. Because FDR is a combination of several different layers of material pulverized, mixed, stabilized and re-compacted, it does not fit neatly into any of these predetermined types of materials considered by the Mechanistic Empirical Design Guide (MEPDG). Current practice is to treat FDR as an unbound granular base layer, but this does not account for the added stability of the selected stabilization technique. However, previous research has shown that FDR may be more accurately characterized as a less-aged asphalt concrete. Until a new layer type is developed that considers the unique properties of these recycled, stabilized base courses, it is essential to understand how to use existing structural design tools to model FDR in a way that best captures its structural benefits. In this research, three different FDR mixtures, two of which were made from Arkansas highway materials, were designed and tested to obtain all necessary material properties required as inputs for the MEPDG to consider this material as both asphalt concrete (AC) and unbound granular material (UGM). Using traffic information from the two Arkansas highways and Arkansas climate data, two different MEPDG models were created for each mixture, one characterizing the FDR layer as an asphalt concrete and the other as an unbound granular material. A stronger correlation was found to exist between temperature and modulus, rather than stress state and modulus. All distress predictions by the MEPDG were higher for the FDR as UGM except AC rutting for one mixture and bottom-up fatigue cracking.

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