Hello, I am planning to build a well-insulated 'shed' type of office
with timber walls secured to thick timber posts, and with concrete
foundations.

I realise I could dig deep holes at each corner for the posts, and
leave it at that. But could someone tell me what those things are
called, made of galvanised steel, that you insert into the concrete
and then secure the posts to (or inser them into), and then tighten up
to make them rock solid?

In a bigger version they are used to secure tall signs to on petrol-
station forecourts; and at well-made 'temporary' buildings such as
some bird hides. I guess hundreds of uk.d-i-yers will know what they
are called! I'd be very grateful if someone could remind me, so it
will be easier for me to check them out.

Many thanks!

Best regards,

John