JM goes on later in the video to say "you can change the...

JM goes on later in the video to say "you can change the additives that go in there and cut costs out"

As far as I know HK would be the most expensive thing in the concrete mix (sand water cement agg), unless we are talking about additives which go into different mix designs eg superplasticizers as an additive in self consolidating concrete (a concrete mix that an ADN ANN mentioned)
so we can replace more expensive additives in concrete which brings the cost down while also keeping the performance benefits?