Concrete is a highly versatile structural material, readily formed into bespoke shapes on site if required. But with concrete, we are always battling with its massive nature when designing floors. Most concrete floors probably weigh five times more than the live load that they end up supporting.
There are more efficient ways with concrete: design post tensioned or pre-stressed concrete floors, or look at something like Cobiax or waffle slabs.
If you want to reduce the embodied carbon of your concrete, then make sure you specify a high percentage of cement replacement in your mix.
Concrete Sketch Book
Download the pdf : Concrete Sketch Book