1- I was told by a South New Jersey, USA paver contractor that a lot of contractors, as a standard practice, in Southern New Jersey, where the soil is mostly sand, simply pour concrete over the compacted sand, and lay pavers over the dried poured concrete (he did not specify whether bedding sand or masonry adhesive was used as a layer between the pavers and the concrete base).
This of course runs contrary to my ICPI training that states you need a "flexible" pavement with a compacted sub-grade, base (which it appears is called sub-base in the UK), sand etc etc..
2- Today I was presented with a set of drawings for a pedestrian pavement application by a municipal engineer. The cross drawing shows the pavers on 1" of bedding sand on top of . . .concrete, again. The concrete base had some sort of a funky drainage system where there were drains placed vertically from the sand setting bed to a pipe, I think, that drained water out to a perimeter drain of some sort.
I looked at the plans, and said, OK . . . .
My initial thought is this: I sell concrete pavers against poured concrete primarily due to the fact that over time, concrete is going to fail and crack under loads and freeze thaw cycles. Soooo . . . . . if concrete is an acceptable base, then besides design considerations, why sell concrete pavers? And wont the joints in a rigid interlocking pavcement simply crack under loads? Is the material used to fill the joints adequate for transferring horizontal load from paver to paver?
I do know the ICPI has reccomendations for overlaying pavers over existing concrete when you want to cover up ugly concrete with pavers, but I'm talking about totally new applications.
What are your thoughts on these applications as a matter of course, in terms of both structural stability and labor savings?
Thanks, PM Dan
