OBone wrote:

Thanks for the replies. I have to run a cable as it will be used for
broadband. I will also place the cable in the conduit before laying it in
place.

It might be more practical to put in a draw-string (use polypropylene
twine) and temporarily plug the ends of the tube to prevent concrete
entering. Then pull your cable through later, when the site conditions
are more amenable to delicate operations.

--
Andy