15 March 2001
it should be level or no higher than 1/8 inch (3 millimeters) above the surrounding patch surface
3.2.8. Seal the patch. After completing the patch, the final step is to seal the edges with an
appropriate joint sealant material (Figure 3.13.). This will give added protection from water
infiltration. The edge seal should be no more than 2 inches (50 millimeters) wide.
3.3. Procedural Steps (Partial-Depth Patch). The following steps should be conducted for the
placement of a partial-depth patch.
3.3.1. Mark the repair area. This is the same as for a full-depth patch (Paragraph 3.2.1.).
3.3.2. Saw the pavement. A concrete saw equipped with a diamond-tip or abrasive blade
(Figures 3.4. and 3.5.) is used to saw the pavement. Saw cuts shall overlap so that a vertical and
square corner is formed (Figure 3.6.). Since diamond-tip blades usually require water, the repair
area should be completely dry before it is repaired. However, there are some types of
diamond-tip blades designed to dry cut asphalt pavements. The abrasive saw blade has
advantages of lower cost and does not require water when sawing. A disadvantage is that the
abrasive blade tends to wear quickly. The depth of cut should be controlled to allow cutting to the
depth required for the repair. Make sure that the saw blade is rated for the RPM of the saw;
otherwise, the blade could shatter during sawing if the blade does not have the correct RPM
3.3.3. Jackhammer and remove defective material. This is the same as for a full-depth patch
3.3.4. Apply tack coat. A thin tack coat should be applied to the edges and bottom of the patch.
This coating provides a good bond between the old and new materials. The patch area edges
shall be clean, dry, and free of any dust to ensure that the tack coat will bond to the edges.