Questions on Reconstructing a Curb Adjacent to AC Pavement 1

[raydefan]

I've got a couple of questions on reconstructing a curb adjacent to AC pavment. The first one is, what is the width of the AC strip to remove and reconstruct adjacent to the new curb. From my experience with LA County Public Works, they want 2', but I've also seen 1'. Is this a constructability issue and if so what is recommended? Also, LA County specifies a slurry seal to be reconstructed instead of AC pavement. They say that it is because AC pavement does not perform as well a slurry seal when there is such a small strip being laid. Anyone have any thoughts on this?

 

[GeoPaveTraffic]

The strip needs to be wide enough to achieve good compaction, so I would go with 3 feet. That is wide enough to use a plate compactor and still have room to move it around. However, if the existing asphalt is in good shape, why not just saw cut the asphalt and place the concrete against the saw cut?

 

[jeremyk55]

I'm assuming that slurry seal is the same as flowable fill. The benefit of using flowable fill is that you don't need room for compaction, so you should be able to get by with a 1' saw cut. I would caution you to verify the integrity of the pavement near the edge. If there is pavement distress outside the 1' strip, I would recommend removing a wider strip.

 

[GeoPaveTraffic]

A slurry seal is nothing like flowable fill. It does require compaction, and I have never seen it put down in greater than a couple of inches of thickness and then only in ruts. Slurry seals are normally only one rock thickness thick.

 

[jeremyk55]

I wasn't sure about what slurry seal was. Locally, it is quite common to use flowable fill (concrete with a high w/c ratio) with an inch or so of asphalt surface ajacent to new/replaced curb. The reduction in labor and asphalt replacement width often makes it economical.

 

[xantics]

I've seen full depth ac plug used for the 1'-2' width of pavement removed when placing curb on existing pavement. This is common practice up here in San Francisco and surrounding cities.