Author Description

Construction of hot mix asphalt (HMA) overlays on top of old concrete pavements is the most common concrete pavement rehabilitation strategy. These overlays, however, are usually subject to reflection cracking related to the movement of the old concrete slab. In addition, these overlays may also be vulnerable to rutting when subjected to large traffic volumes of heavy trucks. Concrete overlays have the advantage of being rut resistant compared to HMA overlays. However, the current national experience of the performance of these overlays is still, relatively, limited compared to HMA overlays. In addition, doubts are often raised about the cost effectiveness of these overlays, the ease of their rehabilitation at the end of their design life and the period of time required closing the road to traffic for ongoing and post construction operations. This report presents an evaluation of three concrete pavement rehabilitation techniques employed on interstate highway I – 65; • A fiber modified HMA overlay on cracked and seated concrete pavement, • An HMA overlay on rubblized concrete pavement, and • An unbonded concrete overlay on 30mm intermediate HMA layer on old concrete pavement. Evaluation of these techniques will continue till the year 2013 by the Research Division Staff. Performance of these rehabilitation techniques is also compared with that of restoration (no overlay) techniques applied in 1985 on the same highway segment. It was concluded that all rehabilitation techniques performed satisfactorily. “Unbonded concrete overlay” segment exhibited the best performance in reflection cracks elimination, structural capacity and skid resistance. “Rubblized” segment exhibited the best performance in ride quality and uniformity of structural capacity. Life cycle cost analysis without road user costs suggested that the “unbonded concrete overlay” was slightly more cost-effective than the other segments.