| dc.description.abstract | Potential challenges associated with depletion of good aggregate sources and management of excess reclaimed asphalt pavement (RAP) stockpiles increasingly motivate use of RAP in portland cement concrete (PCC) as a coarse aggregate replacement. A number of the existing works on use of RAP in PCC for pavement applications only focused on testing mechanical properties of PCC containing RAP (RAP-PCC). The findings addressing other significant aspects, such as durability, failure mechanism, fracture properties, and pavement performance evaluation, are limited; approach to formulate RAP-PCC mixture with minimum strength reduction is not available from the previous work. The lack of a good understanding of RAP-PCC’s behavior and its impact on pavement performance has hindered the implementation of RAP-PCC pavement in the field, and consequently may result in missing an opportunity for a potential good approach to use RAP.
Various aspects including mechanical properties, durability, microstructures, crack pattern, fracture properties, and pavement evaluation related to the use of RAP-PCC for pavement applications were comprehensively evaluated through robust experimental, analytical, and simulative approaches. The mechanical properties and durability of the RAP-PCC were tested through an extensive experimental program, followed by sufficient discussions of the results. An effective method using the total asphalt volumetric fraction to determine the optimum RAP replacement level in a RAP-PCC mixture was developed. The microstructures and crack pattern in the RAP-PCC system were subsequently investigated through several advanced techniques in order to provide scientific evidence and explanation for the RAP-PCC’s behaviors observed in the lab. The fracture properties of the RAP-PCC were experimentally determined through an innovative approach using specimens with semi-circular bending geometry. Finally, evaluation of the performance of rigid pavements containing RAP-PCC was carried out.
Based on the findings from this dissertation, RAP-PCC is a construction material with higher ductility and better fracture properties relative to conventional PCC. It meets the increasing need for sustainability and therefore should be greatly advocated. Although there may still be concerns on implementing single-lift pavement made of RAP-PCC at present, use of RAP-PCC as a bottom lift in a two-lift PCC pavement could be an alternative way to maximize the RAP usage with little compromise of pavement performance. | en |
