EVALUATION OF OHIO SUPERPAVE PROJECTS

Beginning in 1996 the Ohio Department of Transportation (ODOT) used Superpave designed hot-mix asphalt at some construction projects. The introduction of this new technology prompted a need to collect data that would help to relate engineering characteristics of constructed pavements with their future performance. This research study was undertaken to collect data in a uniform, organized manner for the ODOT's initial seven Superpave paving projects. A database was developed to hold information regarding road inventory, pavement design, used materials, job mix formula, construction process, cost, and condition survey. The database structure allows for the inclusion of additional paving projects and subsequent condition surveys. The study concluded (based on available information) that: Pavement constructed using Superpave designed hot-mix asphalt was about 20% more expensive than pavement made of conventionally designed mixes; The cost increase was greater for surface than intermediate mixes; A desired level of field compaction was difficult to obtain in all surface and some intermediate mixes; Differences in the achieved field densities of the asphalt mixes over the duration of the paving process were statistically significant; and Initial pavement distress had a form of ravelling and cracking. The study recommended continuation of the data collection process, changes in the data collection approach, and close examination of the compaction procedure and type of rollers that are used.