I don't think there is any requirement to read an article - that's implicit in the guideline that you don't comment on whether a poster read the original article.

I would say 75-80% of the time I read the comments first, and probably close to 25% of the time I never read the posted article. Also - I found that comment regarding modern concrete, and the pointer to PracticalEngineering to be, by far, the most interesting comment so far - significant contribution. (And yes, I did read both in their entirety)

Perhaps a better response might have been, "The PracticalEngineering article is missing the key detail regarding the exothermic hot baking associated with using quicklime instead of, or in addition to, the slaked lime, and the self-healing properties associated with that. Though the lack of corrosive iron, long curing times, and large structures might be more important - and its unfortunate the original article doesn't mention those as an important detail to at least demonstrate the authors were aware of this."

That link is 'old news'.

What the poster of that link effectively said is that I know all there is about this topic, then post an 'interesting' link as his source, without realising that the current topic is new development not covered by it.