Textile Concrete Panels

For the wall panels, roof, door and pit lining I'm going to be using thin panels of Textile Concrete. I'd never come across it before but its basically plastic-fibre reinforced concrete. You make it by pouring alternating layers of a runny cement slurry and plastic textile, as you can see below:

If you want concrete panels, you used to be able to get asbestos fibre-reinforced panels, but since asbestos rips your lungs to shreds if you inhale the fibres accidentally, its been banned in most countries, including South Africa. As a replacement you can get cellulose fibre reinforced concrete panels, which I would say is a bit more eco-friendly as the cellulose is from plant pulp. Unfortunately these materials are fairly brittle, and so crack easily.

Textile Concrete, on the other hand can flex quite a lot without cracking (it is ductile rather than brittle). This (I think!) is because the cement slurry has a latex-based chemical added to it, which I guess slows down the rate at which cracks propagating through the panel.
Which makes me think, maybe if you got cellulose panels and added the additive, then you would get eco-friendly, flexible concrete panels? (maybe?) Anyway

Over the past couple of weeks I've been playing around with different types and proportions of sand (some from the hardware store, and some from a riverbank down the road) which is mixed with cement, water and a latex-based additive. I've been leaving them for a day and then putting them in a tank of water for a few days to cure, and I've been experimenting with different curing times.