hahahaha. Dude. I wanted to write my post at 682, but figured I should finish out the author's explanation, just to see if he cleared things up in the following chapter, but no, he just doubled down on his position. The fact that the author chose aluminum powder as the secret ingredient shows that he did do research, but for some weird reason he chose a type of concrete that's used for an entirely different purpose. And I have no doubt I'm not the only reader who reacted like "Aluminum? Dafuq? Never heard of that being added to concrete. I wonder what it does?" *jumps on the google* I get that the author needs there to be some modicum of secrecy with his modern day technologies, so a "secret" ingredient like aluminum makes sense from a plot perspective to create WC's "unique" and superior concoction. Just like the tempering method used on the wootz steel swords happened to turn them into super weapons which obviously couldn't exist (even in modern day). At no point could anyone forge a sword, using any material or method, that could cut an entire block of Iron in half with one casual swing, so even some of the modern technologies have a little bit of fantasy mixed in. But the fact is the author is just using concrete as a paving material, he doesn't need to give it some super secret process that suddenly makes it ten times stronger, especially when that technique has no basis in reality, or at least the version that does exist in reality does the exact opposite of what the author wrote. Another reason is that there's no way this recipe could stay secret. I understood how the secret behind the wootz steel sword was able to be kept, but with the quantities of concrete he's going to be producing, there's no way everyone won't find out how it's made. It's nit-picky, but I'm only pointing this out because the author tried to get fancy with something that would have worked just fine had he written it normally. We'll also probably never read about the concrete recipe again as the author's already established the technology, just bothered me, because that's something I always do in these novels, is check to see if the technology the MC is implementing is an actual product. Did this with the different facial products the MC invents implements in Transmigrator Meets Reincarnator. Turns out they were things that replaced the lead based products that came before, and the MC actually used a superior product and valid technological advancement to write it out. I appreciate that attention to detail in that one aspect of the novels I read, bugged me that it didn't happen in this one.