To make this composite material you start with hammer-milled wood fibers. Chips or sawdust would work, but strength and insulation would be compromised. You want the fibers to be as long as possible.

The mix by volume (I use a 5 gallon bucket)
3 parts wood fibers
1 part shredded foam
1 part portland cement

1/2 part water - add more as needed to achieve a workable mix, do not over-water

Mix in a standard concrete mixer. I've found that at least 5 minutes is needed to fully coat all materials with cement.

It's best to start with the water and portland cement, then wood fibers, and finally shredded foam.

The material can be cast into blocks or into wall cavities with a slip-form. 2x6's or 2x12's are temporarily screwed to vertical 2x4's or 2x6's. The mix is poured or shoveled in, compacted (to remove air pockets), and the forms removed after an initial delay. It's best to wait a few hours, but no more than 24 or the form removal will