concrete block - pipe running through it?

Hi,

I have a requirement to create a 400x400x500(d) concrete block for a tie down point.
My problem is that the return from the pool runs straight through the localtion where I want to put the block.....

------[--]-----

-- return line
[] concrete block

The block is being used as an anchor point for a cantilever umbrella.

The pipe is about 65mm in diameter and I was thinking of wrapping a 90mm PVC pipe around it as a sleeve, and then pouring the concrete block. This will give the 65mm pipe a 7.5mm gap all around to protect it fform damage.

Any suggestions/comments ??

Cheers
Geoff

Stuff some Expansion Foam [Sponge Rubber] inbetween the 65 and 90mm pipes to Centre ther and also stop the ingress on Concrete, Sand Dirt etc.
I take it that the 90mm Pipe will extend far past the sides of the Block of Concrete on both sides:)