One alternative to traditional concrete is autoclaved aerated concrete[1], a 70 year old material that's more eco friendly. Some of the advantages are mentioned in this video[2]. I'm guessing higher upfront cost means it's not competitive with traditional concrete.
[1] https://en.wikipedia.org/wiki/Autoclaved_aerated_concrete
[2] https://www.youtube.com/watch?v=FS3BTDBMt7I