Expansion Joint Question for Retail Site

[raydefan]

I need to specify an expansion joint between both a proposed sidewalk and proposed building and proposed sidewalk and proposed curb and gutter. I have found two older plans for similar types of projects, each specifying a different type of expansion joint. The first specifies a '1/4" Thick Polyfoam Expansion Joint Material Set 1/2" below F.S.'. The second specifies both a '1/2" Asphaltic Strip set 3/4" below F.S. with an Elastometric Joint Sealer above it.' My question is, from experience, what is the better alternative? Also, why are the widths of the two joints different, and finally, should a joint sealer be specified fo the first alternative?

 

[GeoPaveTraffic]

First what you are talking about is an isolation joint, not an expansion joint. The goal is to separate the the two different structures.

As for the options you gave, not much difference. I typically see either impregnated asphalt or paper. Joint seal to match what is being used on the street.

 

[oldestguy]

Another point, it is likely the concrete will shrink some in the future, so the width is not important there.

However, for a long concrte pavement there may be heat expansion problems in very hot weather, but it is unlikely that any of the usual joint fillers will not be sufficient to prevent an occasional blow up in very hot weather.

In my experience I hae not ever seen a sidewalk expand so much as to be noticeable.