FIELD INVESTIGATIONS OF SELECTED STRATEGIES TO REDUCE REFLECTIVE CRACKING IN ASPHALT CONCRETE OVERLAYS CONSTRUCTED OVER EXISTING JOINTED CONCRETE PAVEMENTS

Seven pavement rehabilitation strategies for reducing the extent and severity of reflective cracking of asphalt concrete (AC) overlays constructed over jointed concrete pavements were designed and the effectiveness of the strategies was evaluated. The seven rehabilitation strategies were selected after conducting an extensive literature search of documented attempts to reduce reflective cracking. The general descriptions of the seven strategies selected for this study are (a) full-depth repair; (b) crack and seat; (c) crushed stone base interlayer; (d) open-graded AC interlayer, (e) styrene-butadiene-styrene modified seal coat interlayer; (f) 7.6-cm (3-in.) dense graded, coarse surface AC overlay; and (g) 3.8-cm (1.5-in.) dense graded AC overlay. A technique involving sawing and sealing joints in the AC overlay directly over the transverse joints in the concrete pavement was investigated as well. These seven strategies were constructed under carefully controlled conditions, with continuous documentation of material properties, layer thicknesses, and environmental conditions during construction. The preliminary results of the research project, including early-age performance with respect to reflective cracking, rutting, and pavement profile measurements, are presented.