On 16 Dec, 14:29, "John" wrote:
A friend has asked me to install a security post at the end of his driveway,
the sort that lay down flat and lock. *The problem is his drve is block
paving

Don't do it. Although it's fine for a "Don't park here" visual
deterrent, someone will eventually nudge the post by accident and then
it will lift the blocks clean out.

If you do this, lift a few blocks, clear out a bucket-sized hole and
get some concrete down there. Then bolt long and go into the concrete
(maybe just cast some rag bolts in and leave studs poking up).

Otherwise resin fittings are a good idea into blocks. Otherwise use a
big plastic wallplug, but Rawlbolt shield anchors are unnecessary (for
a deterrent post) and will cheerfully split a brick.