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 F. Braham

Committee Member

Kevin D. Hall

Second Committee Member

Clinton M. Wood

Keywords

Applied sciences; Asphalt emulsion; Asphalt foam; Full depth reclamation; Performance testing; Portland cement; Transportation materials

Abstract

Full depth reclamation (FDR) is a flexible pavement recycling technique that has not been explored in the state of Arkansas. FDR is unique in that it incorporates the entire flexible pavement section as well as a predetermined portion of the underlying base and sub-base materials with a stabilizer to create a new, stronger stabilized base course. Common stabilization techniques include the addition of asphalt emulsion, asphalt foam, or cement. Using the North Carolina emulsion FDR mix design, the Wirtgen foam FDR mix design, and the Portland Cement Association cement FDR mix design, field materials from four Arkansas highways in the Fayetteville Shale and Brown Dense Shale areas were gathered and used to produced laboratory stabilized FDR samples to determine the potential future use of these mix designs in Arkansas. Initial testing to determine mix properties were performed, which included determination of gradation, Atterberg limits, and sand equivalency testing. Optimal stabilizer contents were determined using the indirect tensile strength test for asphalt emulsion and asphalt foam stabilization and the unconfined compressive strength test was used for the cement stabilized samples. Once the mix designs were validated and optimal contents were determined, performance testing began on new samples produced at optimal stabilization contents from two of the highways to determine material characteristics and to determine if the performance tests are valid for use with FDR materials. For the asphalt emulsion and asphalt foam samples, performance testing included dynamic modulus in indirect tension mode, creep compliance, semi-circular bend, and indirect tensile strength. The cement stabilized samples were tested using the tube suction test and the semi-circular bend test. Results indicated dynamic modulus is a viable testing indicator for rutting and low temperature cracking, while creep compliance may not be suitable for FDR materials. The semi-circular bend test indicated that it is a testing option when using asphalt stabilized materials but another option may be needed for cement stabilization. The indirect tensile strength and tube suction tests are quantifiable moisture susceptibility tests that worked well with the FDR materials.

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