| dc.description.abstract | Conventional methods of replacing roadways are beginning to negatively impact the environment. The continued use of high volumes of cement will continue to exacerbate the increasing levels of carbon dioxide. In addition to cement concerns, removing existing deteriorated pavement will continue to stress already overburdened landfills. In an attempt to alleviate these issues, engineers have been investigating methods to increase the environmental sustainability of concrete pavements. One method being investigated to reduce the overall cement content, and another is to incorporate construction waste in the form of recycled concrete aggregate (RCA) and fly ash. The first method, Cement-Limiting, investigated three different aggregate optimization techniques (Coarseness/Workability, Percent Retained, and Power 45) to reduce the amount of void space in a concrete mix, allowing a reduction in the cementitious material. The second method, High-Volume Recycled Material, investigated using up to 100% RCA replacement of natural aggregate and up to 75% fly ash replacement of cementitious material.
To test the performance of both of these mix designs, multiple ASTM laboratory tests were performed on the fresh and hardened concrete, as well as full-scale, instrumented field implementations. These results were monitored and compared to the Oklahoma Department of Transportation (ODOT) Specifications, as well as to commonly used concrete mix designs. Analysis of the results indicate that the Cement-Limiting mix design adequately performed or surpassed ODOT Specifications the Class A standard pavement concrete mix and the, while the High-Volume Recycled Material mix design performed up to the ODOT Specifications, but not to Class A mix. | en_US |
