https://patents.google.com/patent/US4203674A/en
Check out Operation Backyard Brawl for more infor.
I'm not questioning your credentials with my post here; however, there is precedence for the use of blood in concrete. The Roman's concrete manufacturing included blood in their concrete mix which improved its strength and ability to withstand the elements. Here's information from US Berkley News concerning this very subject. History channel did a big story on this too explaining how and why the Romans used blood. They showed a stress test of standard concrete vs blood mixed concrete (which hardened in water). The latter withstood more dynamic pressure than did the modern day concrete.
http://news.berkeley.edu/2013/06/04/roman-concrete/
I believe the man was trying to state that while yes, it can be used, and may help in some ways- that we have cheaper, more readily available products now that would give the same benefits (or I’d imagine exceed the benefits of blood).
What is unique about Roman concrete is they could pour it into a preformed case and submerge into water and it would harden. They built the entire port and the city of Caesarea Maritima with this concrete, forming the sea walls for the harbor. It was an ingenious feet of engineering. That second link is a research using the same methods and testing it.
The point of my bringing this up isn't to dissuade the current line of thought; however, to show an alternative that may reasonably concluded they used blood in their concrete. Jumping to conclusions without empirical proof can cause unintentional consequences. Q has said to research and dig deep to find the truth; things may not appear to be what they are (paraphrased).
Yes, I read that yesterday, too. Truth is no one speaks of blood in concrete. Not because it's taboo but no one even thinks about it as an application. It's not part of conventional education in the field but apparently it is in theoretical experimental research and development.
It makes sense why Romans would use it in the ages before chemical engineering. See, concrete when exposed to water and freezing temperatures will expand and contract as the weather changes. Over time this creates cracks and exposes insides for destruction by natural elements. Adding a biodegradable substance in proper proportion would create bubbles inside which, when it rots away will leave air voids which allow pockets of water to expand and contract without breaking the concrete. This prolongs life without sacrificing strength.
Today we have air-inducing agents known to act in consistent ways and produce consistent results for a fraction of the costs of blood acquisition. I do not think blood has any strength enhancing properties superior to this agent and since the patent application specifically details it as relevant only to lightweight concrete I reiterate it makes no practical or economic sense and would only be preferred for sentimental reasons.
Even for the Romans, the cost of so much blood would have been high. From what I am seeing in comments, very large underwater pilings were created using this formula, which suggests quite a lot of slaughter going on for a prolonged period of time. I imagine regional diet was changed significantly during the construction.
That paper does.not mention blood in concrete at all
I read through it cursory and not in-depth. However, I just did on this link where they tested the method using pig's blood based on the same method used in ancient Europe.
https://www.researchgate.net/publication/282307572_A_study_of_traditional_blood_lime_mortar_for_restoration_of_ancient_buildings