Bricks, Masonry, Asphalt and Concrete - cobblestones not sticking to concrete

I'm laying cobblestones as edging for my driveway, which will be paved after, using 80 lb bags of Sackrete Concrete Mix.

However, since the sizes of these stones vary widely, some didn't need to be tamped in much and therefore are basically just resting on the surface of the concrete with no adhesion to it.

Is there an adhesive I should use for these stones?

My paving contractor suggested I Lay these in concrete but to leave "finger joints" between the stones, but to NOT mortar the joints. (I think the reasoning being drainage, and to go with the rustic look of the size-varied stones.) Then just backfill the rear side with dirt.

I liked the idea, so as to save the time of mortaring the joints, but now I'm wondering if this will be sturdy enough.

Thoughts?

It sounds like we need more information.

I never heard of a paving contractor using 80# bags of Sakrete for a driveway. It is costly and will not give you a durable driveway, despite the best efforts of Sakrete to make a uniform product. - They just do not have a product that is as cheap to use or as durable as ready-mix concrete.

What is the size of the driveway and what is the base under the driveway and the edging?

Cobblestone can make an attractive edging, but they have nothing to do with the paving. They have no structural value, but can contain the concrete when he pours it.

Never use an adhesive. If the Romans did, it would have been popular by now. They did have very good adhesives.

There seems to be more to this than a simple driveway. - More info please.

Dick

Okay, thanks for your interest. Feel free to ask any specific questions. I see how I confused you, my sentence structure was awful!

The contractor will pave with asphalt, while I have elected to do the edging MYSELF, to save some money. The Sakrete is only being used by ME, as a footing for the edging.

For edging, he charges $15/ft to reuse my existing stones, or $20/ft with new. I have more time than money right now, so I'm doing it, and the contractor was kind enough to show me how to drive some pins and pull some lines to get me going. I'm doing a run of about 80' on one side of the driveway and 30' on the other.

After I'm finished making a mess of the edging the contractor will come in to scrape/level and blacktop.

So, as a novice, I am getting 10-12 80lb bags of Sakrete at a time, setting about 4-5 stones from each, doing things poorly, and (hopefully) getting better as I go. These loose stones were from the start of the job, when I was at my worst. Unfortunately, they are at the top of the driveway (by the sidewalk) where they will be most seen, and somewhat likely to get inadvertently driven on from time to time. To make matters worse, I probably shorted the footing there trying to stretch out my concrete.

I can think of at least 4 reasons why these rocks didn't stick:

1. As they were existing, and formerly dry laid, they may have had a thin layer of dry soil on their bottoms.

2. I think my helper jostled some while they were settling.

3. My mix may have been too dry. It's a bit crumbly.

4. They just weren't tamped deep enough into the mix.

Therefore, I have some loose stones I'd like to reset, as well as a few others I'd like to make loose in order to re-do them for esthetic reasons. Thus, how best to adhere those stones to the footing without having to bust up the footing too much and without adding too much height with mortar from underneath?

Oh, another bit of info... The stones range in height from about 6"-10", but I only want about 1.5"-2" of reveal above the pavement, so there should be some degree of support from the pavement and back filling with dirt. Think it's okay to keep the joints open?