It is my understanding that one of the common methods, at one time at least, of disposing of chips and certifying them as destroyed was to mix them into concrete or asphalt and use them in construction (Foundations etc.), remodeling and parking lots.... I recalled contributing to a similar thread some time ago and have done a search through the archives to find some of the past posts that will address your question. I had done a GOOGLE search at that time and came up with a little information. It seems that a big part of the discovery of chunks of such concrete filled with chips was during the demolition of The Dunes. Check out some of the posts to the attached link. As usual, the entire thread appears at the bottom of the attached post.

http://www.thechipboard.com/cgi-bin/tcbarc07/tcbarc07.pl?read=202830

From what I have read it seems that there could be chunks of concrete containing chips around parks, golf courses, other casino properties etc. Wherever someone might have needed some fill to add to a landscape or construction project.