Paver surface problem

We have an extensive mortar/brick paver sidewalk which nearly encircles our house. It is on a concrete slab. It is about 18 years old and has begun to fail. The brick pavers have started spalling, cracking the faces and the mortar. At one time 3-4 years ago a mason came out and cut out about 40 of the pavers and replaced them, but it was expensive and I don't think we can keep up these repairs.

I am interested in thoughts on replacing this surface. My thought was to remove the pavers down to the slab and then lay concrete block or brick right down on the concrete slab, without mortar. This way I could pull up a piece and replace it if damaged.

Would this work? Are there better solutions? How would I secure the edges and keep the bricks or blocks from working their way off the slab?

Thanks in advance!

SB