De or het betonwapening?

The correct Dutch article is:

de betonwapening

Rule Words ending in -ing: almost always de. See the rule

How to use betonwapening

the betonwapeningde betonwapening
this betonwapeningdeze betonwapening
that betonwapeningdie betonwapening
our betonwapeningonze betonwapening
your betonwapeningjouw betonwapening
every betonwapeningelke betonwapening
which betonwapening?welke betonwapening?
a big betonwapening / the big betonwapeningeen grote betonwapening, de grote betonwapening