[iasmseanyoung]

Concrete has a high compressive strength without steel rebars. Steel rebars are added to concrete to increase its tensile and sheer strength. The article alludes that these polymer reinforcements can replace steel but then only talks about increasing the concretes compressive strength, which exactly not why they're used.

[jcims]

The article did kind of circle around the objective of the work without digging into it. The picture and some of the text (strain test) indicates they are evaluating tensile loads, but it didn't really say if this was intended to increase mechanical performance, reduce weight, reduce concrete used, etc.

I think the point, given the title, is to reduce the volume of concrete that is cured for a given pour by replacing some of it with polymers.

[mjevans]

Using even less material seems likely to lead to most buildings trying to do only that and failing to include any other mechanism for acoustic isolation and privacy.

I am almost equally worried about other previously assumed goals that traditional construction methods happen to fulfill but which could be overlooked due to under-specification. What things? I don't know, and my worry is that experts in those fields might not either until that data is gleaned the hard way.