General comments/chat, page-41954

There may be large amounts of flyash buried. But most flyash is not useful for concrete. If LOI is up air entrainment becomes highly variable. Many buried flyashes would need to be processed to comply to the current specs consuming more power and increasing costs. Three different avenues to getting future concrete producing less carbon follow.

1 Geopolymer concretes may eventually become acceptable and depending on the constituents they may be low to 0 carbon. Very early days in this area.

2 The interest in metakaolins is as a flyash replacement not so much a cement replacement like a geopolymer would. These are low cost $100-$200 per tonne range. Historically they have been inconsistent in properties unless processed which drives price up and makes them non competitive against flyash. But when flyash goes they may be more attractive.

3. Additives that replace some cement and flyash while improving properties. This is ADN's wheel house. if a geopolymer has some undesirable properties the additive may assist. Equally any flyash replacing SCM like metakaolin may need the additive to get the right properties. So I think an haloysite kaolin is well placed to assist in any future direction.