> Many interesting points.
> Corpuscles Wrote:
> "Limestone is not entirely a product of
> - Interesting that the softest, (marble), would
> be the most reliant on pressure, if that's what
> you were saying there. If so, its counter
They are roughly equivalent it has to do with the chemistry.
I suggest you google that question.
Yes marble has to be exposed to heat, but such likely provided by crust folding pressure
> I'm in Canada btw, and spent many years rock
> climbing on our natural limestone escarpments,
> (which I just identified as dolomite), as well as
> many other places throughout North America. Even
> on my local harder version of limestone, the hand
> holds of popular routes become very polished and
> smooth just from hand friction. More so than any
> other rock I've climbed on, (including Granite,
> Sandstone, Basalt, volcanic tuff, quartz
> monzonite, etc.)
You are braver than I. Hang on tight!
> "Davidovits standard for limestone based
> geopolymer concrete is 90 MPA and he claims they
> have achieved 150 MPA."
> - Is that modern man made today, or is that
> referring to ancient identified geopolymer
> megalithic limestone?
Of course that is modern. With the advantages of detailed equipment to adjust the recipe.
I do not know (without reading papers) what the parameters of hardness from the megalithic sites were.
But an interesting question. I might try and find the analysis tables.
> "In slabs they still sometimes put in steel
> reinforcement but Geopolymer has extraordinary
> tensile strength already"
> - I realize, but for my cost efficiency
> presumptions, its probably cheaper to add rebar
> and less material to maintain tensile strength.
The added material is typically 3%. The rebar is mainly to overcome Building code standards imposed rather than a major need.
> "You are touching on some areas which restricts
> many from accepting/ considering the possibility
> of geopolymer use by Ancients. "
> - Good point. But coming from a perspective of
> the place holder term of 'magic stone softening',
> and reconsidering the geopolymer approach,
> strictly from the merits of the chemical analysis,
> I find the weakest part of geopolymer theory is
> the suggestion it was treated, produced, and
> worked with like modern day cement, and the
> remains don't support it to me, (lack of repeating
> patterns, simplistic brick shape vs polygonal,
> pillowed, etc.).
In regards to much of it, think of it as a plasticine like render. Have you ever cement rendered an old brick wall?
I do not think much of it involved molds.
You watched vid 4 - Egypt pyramids
The draw back stated by Davidovits in regard to the non associated magnetic survey was the lack of samples. Often they only get a small scrape not a core drill of a block which may have been mainly entirely natural stone , which was supplemented by some trowelled on render.
On the rock softening conjecture.
Copper smelters produce around one tonne of sulphuric acid for each tonne of copper concentrate. * Copper miners using the solvent extraction electro-winning process need around 3.0-3.5 tonnes of sulphuric acid to turn ore into one tonne of copper metal.
Try some on a block of granite and stand back and watch! ;-)
> I get the impression people think the repeating
> pattern of a brick is some kind of advancement,
> but the brick is stupid easy. Its those polygonal
> shapes that's next level. If I judge the ancients
> from their polygonal systems, with the assumption
> they had a concrete system that lead to that, then
> they had to have spent a LONG time with bricks
> first before getting there, and I can't see enough
> of that progression evidence.
Well in places like Mesopotamia and Egypt they did have lots of experience with brick (mud/clay bricks)
However, as you have been following, along lets talk "Sacsayhuaman" even though not intended in the thread OP.
You will have noted the main bulk of the walls are comprised of small stone and dirt (likely clay enriched) and has a shell of polygonal some very big blocks. You will also have noted a number of places where simply smaller stones are stacked on top of such. The problem with a stack of smaller stones is that with a shake if one stone is dislodged then an avalanche can occur. So if "they" had ability to mimic a geopolymer mix, then they smothered a group of smaller stones binding them together to form a larger less likely to move stone. They also shaped that group in 3 dimensions curves front to back, top to bottom, and the malleable external substance allowed a cut separation (or maybe a flax biodegradable mat) to create intricate close joins to create artificial movement joints. You know - the lines on your concrete are there so that if the concrete expands ,it will crack at that point, not in the middle in a crazed manner.
Mayans Inca whoever etc - Not very high tech, BUT extremely smart!
> So with a mind to reverse engineering from what I
> see, if it WAS geopolymer manufactured rock, then
> there had to be some factor about it, that limited
> it to a very thick viscosity like clay at its
> loosest. At least then I could see the challenge
> with mold making because you can't force thick
> clay into complex shapes. It would be just easier
> to approach wall building as blobs with cleaned up
> faces. But then you gotta wonder about those
No molds necessary in most cases.
Best mix for modern rendering If no time then just approx. at 3.45 mark for 15secs
The ancients seem to have applied a very thick coat. Sometimes it was too wet so they had to prop it at the bottom causing dents and bulges in the finished render.
Yep I know I seem crazy - likely true! ;-)
> I don't know. Alot hurts the geopolymer idea if
> its presented as cement. I think that part of its
> association needs to be refined and clarified to
> more accurately reflect the actual archeological
Have you watched Davidovits vid of making it? You could easily do it yourself especially if you hang off rocks at dizzy heights.
I probably should get off this hobby horse soon?
Edit in italic
Edited 1 time(s). Last edit at 08-Jan-20 22:17 by Corpuscles.