Now, combine these polymer reinforced technologies with 3-D printing advances to remodel our world!

And CO2 free cement? Has New Atlas ever had a look at this ? https://tececo.com/simple.eco-cement.php

Unless I've missed something this is not new. We were using ready mixed concrete with fibre filaments added to reduce rebar quantities and shrinkage cracking 10 years ago in South Africa.

Interesting but only if the polyethylene came from a recycled source as we really don't need to add more plastic into the environment! May as well use hemp fibre instead as that has been found to be an excellent addition.

The use of PP fibers are decades old, and "metal fibers" are NEVER put into concrete - re-bar and re-wire, yes. Pre- or post-tensioned rods or cables, yes. I mean, I'm sure this is an advance, but I don't understand what it is.

I suspect the whole 'too much CO2' greenhouse gas promotion is false. Greenhouses still have to use CO2 generators in order to help their plants grow. And, oh yeah, CO2 is not a toxic gas, as is CO. Hempcrete may still offer a better solution.

Most of the fibered cement is still asbestos cement, as it was put on as asbestos shingles between 1920 and 1970. Asbestos is relatively cheap and has the right elastic modulus to make a two phase material when combined with cement. It bonds well to the cement. Glass fibered cement has been used to replace asbestos. Glass rebar is used in salt water applications. Graphite works well, as it can have the same modulus as steel and asbestos but it is much more expensive.

As others have indicatated, HEMPCRETE BEATS THEM ALL. Stop trying to reinvent the wheel!

So the plants will have less CO2 to feed on, less plants, less oxygen for us all to breathe, less oxygen, less mental capacity, more cancer and disease. And CO2 has been debunked as a cause of global warming now, with Russian scientists having been saying for years that we are in fact heading into a mini ice age, and the science bears that out with global temperatures actually dropping now, not rising. Besides, atmospheric CO2 levels have never had any influence on global temperature in past centuries, and the gradually changing relative positions between the Sun and Earth in varying orbital cycles are what are really responsible for changing global temperatures. I don't think that stuff will really be very green when future generations find asbestos-like deposits of the plastic fibres in the soil when this 'concrete' breaks down. I am all for materials being used that really are green in how they eventually do eventually break down. Roman concrete structures from 2,000 year ago still exist, but they used a different method of production, using sea water to produce such resilience, and their concrete does not eventually break down to leave nasty sharp plastic fibres in the ground. See; 'Scientist believes she’s found the recipe for ancient Roman concrete used 2,000 years ago'. Also; 'Mystery of 2,000-year-old Roman concrete solved by scientists'.

Yes in the old days we did use metal fibers in concrete, we are currently using fiberglass.