Two separately funded projects examined the potential for ASR in aggregates. The first project was sponsored by the Wyoming Department of Transportation (WYDoT) while the second one was sponsored by the Oregon Transportation Research and Education Consortium (OTREC). For the WYDoT sponsored project, eight different Wyoming aggregate sources were chosen to be analyzed and classified for alkali-silica reaction, or ASR, reactivity. Wyoming aggregates were tested using three different laboratory methods including the Concrete Prism Test (CPT), the Accelerated Mortar Bar Test (AMBT), the Chinese Accelerated Mortar Bar Test (CAMBT), as well as large scale field blocks exposed to outdoor conditions. Preliminary conclusions from laboratory testing were made about the reactivity of each aggregate source. Specimen bars from each test and cores from the large scale blocks were subjected to petrographic analysis to confirm the presence of ASR. The OTREC project consisted of a four university study that took previous large scale field blocks and re-crushed them into recycled concrete aggregate (RCA). A modified AMBT test procedure was used to account for modified material properties due to the presence of RCA. Next, a second round of modified AMBT testing was performed with two university laboratories using different RCA sources. Large scale field specimens were cast using RCA and subjected to outdoor exposure for comparison at a later date.