Thrust blocks are made of concrete so pipes can't move. Typically at the 90 ell the concrete is poured so the pipe can't move.

Good luck,
Tom

So I just mix up some cement and pour it in the hole next to the ell - no form or anything?

Thats about it. On large pipe for golf courses we would prefab them then set the prefab with more concrete on site.

Just takes the flex out of the pipe in the case of a surge.

Good luck,
Tom

Thanks Tom.