Thesis
Evaluation of high percentage recycled asphalt pavement as base course materials
Washington State University
Master of Science (MS), Washington State University
2011
Handle:
https://hdl.handle.net/2376/100311
Abstract
The use of recycled materials for construction is beneficial to both the environment and the economy. Recycled asphalt pavement (RAP) is one of the most commonly used recycled materials. Different state departments of transportation allow the use of RAP in base materials at different percentages. Evaluation of engineering performance of base materials with RAP is important for proper pavement design. This study evaluated the potential use of high percentage recycled asphalt pavement as base course material without compromising the pavement performance in terms of stiffness, permanent deformation and permeability. RAP from two different sources were collected for lab testing. Resilient modulus (Mr) was selected to represent the stiffness of base course material and the models that account for the effects of moisture content on the resilient modulus of unbound materials were evaluated on crushed aggregates with RAP. In addition, models were proposed to account for the effects of temperature on the resilient modulus of base materials with RAP. Based on Mr testing results, permanent deformation was compared for specimens containing different percentages of RAP to evaluate the rutting potential. It was found adding RAP to virgin aggregate increased resilient modulus, but also increased rutting potential under certain conditions, such as 60°C (140°F), OMC-4 or OMC-2; and OMC at 20°C for RAP1. Repeated load triaxial test was conducted in order to evaluate the effect of RAP percentage on permanent strain of base course material. Tseng and Lytton introduced a permanent deformation prediction model in 1989 for granular base course material, and the model was modified by adding RAP percentage as a parameter for base course materials containing RAP. Constant head permeability tests were conducted for samples containing different percentages of RAP, and the results suggested that coefficient of permeability decreased with the increase of RAP percentage. In addition, freeze-thaw conditioning was applied to specimens to investigate the effect on and permeability. X-Ray Computed Tomography scanning was conducted for specimens containing different percentages of RAP. Lower air void was detected for specimens containing higher RAP percentage, which might be one of the reasons leading to higher Mr and lower permeability.
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Details
- Title
- Evaluation of high percentage recycled asphalt pavement as base course materials
- Creators
- Mengqi Wu
- Contributors
- Haifang Wen (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525003401842
- Language
- English
- Resource Type
- Thesis