Irradiated by gamma rays, heh?
Can it be called HULKcrete?

Strictly speaking, this is downcycling rather than recycling.
Recycling would be making new plastic bottles from used plastic bottles.
Also, how would this concrete be disposed of when the building is eventually demolished?
Regular concrete can be recycled by crushing and grading it in to aggregates. Can that be done with this "plastic concrete"?

does it make the concrete harder or softer? i'm thinking of using it for roads. any place that gets worn by abrasion.

This could be valuable for nuclear waste storage.

No reason it could not be recycled. The plastic is ground to a powder.

I wonder how adding the ground irradiated plastic compares to adding fly ash, silica fume or polyvinyl alcohol and whether it will additionally strengthen concrete that has also been strengthened using those other additions.

I know of gamma rays being used in England for substantially extending shelf life of fresh produce. Just wonder why it is not more widely used and a lot of food is allowed to rot !

What concrete was used? Grancrete brags it is 500% stronger. And what is the cost of irradiation?
I don't support any eco-measures that need subsidy. Doing so is asking to be scammed by politicians/business. See: Alternative energy.

Plants love carbon dioxide. Water vapor is the real greenhouse gas. Let's do something about that.

https://newatlas.com/cement-overlooked-carbon-sink/46569/ Would be funny if this caused the new found carbon sink mechanism to fail and make concrete once again a net producer of carbon rather than the new found carbon sink that it is now considered to be.