SAWING AND SEALING OF JOINTS IN ASPHALTIC CONCRETE OVERLAYS

One method used to rehabilitate portland cement concrete pavements is to place an asphaltic concrete (AC) overlay on the existing pavement. The overlay, which can improve the pavement's structural capacity and rideability, can also create maintenance problems. These problems result from reflection cracking at the location of joints and cracks in the underlying slab. A method used to control the reflection cracking problem is to saw a joint in the AC overlay above the existing joint and then seal the joint (i.e., sawing and sealing). The performance of AC overlays with sawing and sealing was the subject of a national study. Pavements with up to 10 years of service life were evaluated through condition surveys, roughness measurements, and deflection measurements. Both saw-and-seal pavements and control sections were evaluated. The analysis indicated that sawing and sealing improves the rideability of the AC overlay and significantly reduces the amount of transverse reflection cracking.