Identifier

etd-04102008-035013

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

Permanent deformation and moisture damage are the most common distresses found in asphalt pavements today. Extensive experimental studies have revealed that the use of hydrated lime in Hot-Mix Asphalt (HMA) mixtures can reduce permanent deformation, long-term aging, and moisture susceptibility of mixtures. In addition, it increases the stiffness and fatigue resistance of mixtures. The objectives of this study were to evaluate (1) the fundamental engineering properties of HMA mixtures containing hydrated lime compared to conventional mixtures designed to meet the current Louisiana Superpave specifications and (2) the influence of the method of addition of hydrated lime on the mechanical properties of HMA mixtures. Nine 19.0 mm Level 2 HMA mixtures were designed and examined. Siliceous limestone aggregates that are commonly used in Louisiana were included in this study. The nine mixtures were divided into three sets where the first set of three mixtures named as conventional or control mixtures did not include hydrated lime, and contained two SB polymer modified asphalt cement meeting Louisiana specifications for PG 76-22M, PG 70-22M, and a neat PG 64-22 asphalt. Mixtures in the second set included hydrated lime that was incorporated into the aggregate/asphalt cement mixture as slurry, whereas hydrated lime was blended dry with the asphalt cement for the third set of mixtures. For the latter two sets, the asphalt cements used were identical to the ones used in the first set, namely PG 76-22M, PG 70-22M, and PG 64-22. Mechanistic tests namely, Indirect Tensile Strength test, Semi-Circular Bend test, Dissipated Creep Strain Energy test, Dynamic Modulus test, Flow Number test, Flow Time test, and Loaded Wheel Tracking test were conducted to define the permanent deformation and endurance life of HMA mixtures with and without hydrated lime. In addition, physical and rheological tests on asphalt binders were performed. The overall results indicated that the addition of hydrated lime improved the permanent deformation characteristics of the HMA mixtures. This improvement was substantial particularly at higher testing temperatures for mixtures containing polymer modified asphalt binders.

Date

2008

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Louay N. Mohammad

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