Field Experiences with RDD and Overlay Tester for Concrete Pavement Rehabilitation

Abstract

Since reflective cracking is related to both the existing pavement condition and the overlay material, appropriate tools are needed to characterize both properties. The rolling dynamic deflectometer (RDD) was employed to measure the continuous deflection profiles that relate to vertical movements of the underlying joints and cracks. An overlay tester (OT) was utilized to characterize the asphalt mix’s ability to resist reflective cracking. The reported threshold values were employed in the study that include: (1) W1–W3=6.5 mils for composite pavement with old asphalt concrete (AC) overlay; (2) W1–W3=5.5 mils for exposed concrete pavement; and (3) 700 cycles of the OT were employed to evaluate six field rehabilitation projects (SH12, IH20, US96, SH73, SH225, and IH44). It was found that although there were severe transverse cracks and spalling on US96, all W1–W3 deflections were less than 5.5 mils , indicating low risk for reflective cracking. A stone-mastic asphalt (SMA) layer was placed 3 years ago and t...