sci.archaeology
[Top] [All Lists]

Re: Scientist Says Concrete Was Used in Pyramids

Subject: Re: Scientist Says Concrete Was Used in Pyramids
From: Florian
Date: Mon, 4 Dec 2006 14:00:39 +0100
Newsgroups: sci.archaeology
prd <X_header@xxxxxxxxxxx> wrote:

> > Watch the movie?
> 
> I also am not going to watch the 'passion of the christ', either nor any
> number of movies recommended by idealistic pundits. I go to movies to be
> entertained, not educated, for education you better to read the
> peer-reviewed primary literture. 
>   Otherwise you would tend yourself to Mel Gibson like faiths in
> life, living someone elses problems. 


Frankly, it won't kill you to watch a 4 min movie on the internet.
Especially when it helps to understand the point of view of a person.

> > I suppose this is much easier to carry concrete in bags than carrying 2
> > tons blocks.
> 
> They would have carried it in trays, when water was added, mixed and the
> with two men dumped into a form, the trays carried back and reloaded.

Nope. The water can not be added in situ, just before pouring in the
cast.
The limestone has to be soaken for days before it is usable.
It's just silly. if you watch that tiny movie you'll understand
immediately that your view of the process is wrong.



> > Building a pyramid was also about faith and devotion.
> 
> Faith does not produce offspring, faith does not feed a family, faith
> does not plant grain or irrigate it, faith cannot make the sun come up
> nor go down.

May be not. But it certainly push believer to make extraordinary (some
will say silly) things.

 
> > Those things are
> > hardly consistent over long period of time. A lost technic could also
> > prevent further gigantic building.
> 
> But technically a pyramid is easy to build. You can buy sqaure cobble
> at just about any material yard, start with one stone on one corner, begin
> adding one layer of stone at a time, morter between the joints, you can
> keep doing this indefinitely 
> > How can it be identical??? moving a 2 stone blocks to the top of a
> > pyramid can't be compared to moving limestone concrete in bags.
> 
> You assume that the scalar problem cannot be worked out. Consider
> 1 man can carry, repeatedly 1 50 lb bag of concrete. 
> If I give that man a wheel burrow he can carry 300 lbs of concrete. 
> If I put 4 men on a cart they can carry a ton of concrete. If I put
> 10 men on a massive cart, they can carry 20 tons of concrete. Bags are
> no longer of any importance. [...]

You missed the point. The issue here is moving the thing up. It is
faster to move reconstituted limestone in bags to the top of a 100
m-high pyramid than use levee to elevate a 2 tons block.


> > 3 hours a block? I did not see any clues about the time needed to quarry
> > a block in the link you cited. I'm interested in any reference on the
> > subject proving your point.
>  
> This is based on my experience. Although I would need a sample of the
> stone to be more accurate, assuming that their limestone was similar in
> hardness to the limestone we used to have to cutthrough in our remodeling
> projects. 

OK. Your experience. I rather like another estimate (actually quite hard
to find on the web).


> All concrete (except asphalt concrete) is limestone based.
> 
> Limestone --Heat--> CaO (see below)
> CaO + Ash + Sand + Aggregate + Water = Concrete. 
> Some of the more silty sand and ash are some of the harder
> ancient concretes. 

Sorry. That is not the chemistry involve in reconstituted limestone.
there is no heating or CaO involved.

Chemical reaction1: 
Si 2O5,Al2(OH)4 + 2NaOH = > Na2O.2SiO2Al2O3.nH2O 
 kaolinite clay + soda = > hydrosodalite 
 
Chemical reaction 2:  
Na 2CO3 + Ca(OH)2 = > 2NaOH + CaCO3 
Sodium carbonate (Egyptian natron) + lime = > soda + limestone 
 
Summary of the re-agglomerated stone binder chemical formula:  
clay + natron + lime = > feldspathoids + limestone (i.e. a natural
stone).

> Then it is not concrete, because in ancient Aluminum poor cements the
> reaction that gives rise to concretes strength is between the CaOH, the
> Ash, and the Si-O, also known as Alkali-Silicon Reaction.

Don't call it concrete if you want. May be "reconstitued limestone" is
more appropriate.
I stripped the following text because, although very interesting it does
not apply to the chemistry of  "reconstitued limestone".
I hope you don't mind :-)


> > You're welcome. But calling me a liar won't help the debates. right?
> 
> No, but it points out a fact, when confronted with critiques you
> respond with falsitudes and inaccuracies (see post by D. Weller for
> but another obvious example of your tailspin). 

I may be inaccurate sometimes, but that is because I don't know the
subject very well. I learn while reading the different posts and looking
for more information on the internet. 

My point with D. Weller was that Lehner considered the quarry worker as
part of the 2500 primary worker, i. e., they were not thousands of
quarry workers.

 
> Concrete and lime based cements are an interesting topic of archaeological
> discussion, even on my very strict standards, but more often than
> not we don't discuss the archaeology of concrete, but the debunking of
> some kooks theory. As you will read above. 

I don't feel concern by those kooks theory.
My interest in the concrete theory just arise from the later paper of Dr
Barsoum.
I thought his work was very interesting and deserved to be taken in
consideration even if more research is needed to confirm his findings.
Then I figure out that another scientist (Davidovits) made similar
obervation using X-Ray analysis and developed a complete theory based on
original geopolymer chemistry.
that's all.


> IOW, he believes the stones were built in Situ, which means why do 
> they build the structure in blocks at all. you have 4 guys hauling a cart
> 1 guy hauling water, they mix the cement and spread it out over a fill
> in area. There is no need for blocks. 

The process is different than mixing water and concrete then pouring
right after mixing. I already offer some possible answers for
blocks-vs-large area:

- evolution of the previous brick technology that involves casting of
clay.
- drying time
- crew size
- ergonomy of cast size
- mix of quarry stones and reconstituted stones
- size of the batch of reconstituted limestone
- all of the above




> Secondarily the density of concrete
> is 2.3 to 2.5 and the density of the pyramids is 1.8. 

One more time. 2.3 to 2.5 density is for sand concrete, not for
reconstituted limestone.

> BTW just because limestone is soft does not mean if falls apart in water.
> There are limestones in texas so soft you can imprint them with your fist
> and have survived the 'flash flood capital of the world' for 50 million
> years. 

The limestone in question contains a lot of kaolin clay. that's why it
disagregates easily.


-- 
Florian

"Tout est au mieux dans le meilleur des mondes possibles"
Voltaire vs Leibniz

<Prev in Thread] Current Thread [Next in Thread>