I hypothesize that one of the reasons the yarn performed so much better than the deer net is because it is more permeable and thus formed a better bond with the concrete.
In this scenario, I would imagine that it would be "locally tensioned" because the cement is effectively tightly bonded across any point of stress. Would be an interesting experiment!
Isn't the point of pre-tensioning is not the actual tension on the reinforcement, but the pre-loading of the concrete - so it needs to happen everywhere in the volume of the concrete, not just next to the reinforcement?
Interesting point; I see what you are saying like during the curing process, the tension in the yarn weave itself would pre-tension the dried slab. But I wonder if acrylic yarn would have a sufficient effect and to what extent.
If anyone has science fairs coming up, these seem like excellent experiments!
If it's stretchy or wavy, the concrete may crack before it starts to produce tension