what is mastic adhesive?
Answers:
I think you're referring to the adhesives sold under the names "no nails" or "nail power". They enable you to fix quite heavy things onto a sound support without the need for drills, plugs, nails or screws.
They come in a tube which is loaded into a mastic gun ,some don't even need this, they have their own system.
It tells you on the tube what weightin lbs or kg the adhesive can support.
This stuff is great for fixing plinths, tiles, even shelves.
Other answers:
petroleum based ceramic tile adhesive
petroleum based ceramic tile adhesive
well yes and there is also a mastic for vinyl sheet flooring
Tubes of silicon base adhesive, used for joining & sealing the joints in fishtanks for example