Concrete

ZVar wrote:

Maldorian wrote:Steel is the only Metal you can use for reinforced concrete, because of the linear Expansion coefficient.

If the temperature changes, material expand with different rates. Concrete and steel expand with nearby the same rate, so that you can mix it.

Other materials would blow up the concrete if the temperature changes.

I was going to say the same thing, thank you.
One thing I wonder though, is since Iron and Steel are basically the same metal do they expand and contract at the same rate?
Or is the higher carbon in steel what causes the expansion/contraction to match concrete?

evilauthor wrote:Prior to Charis' industrial revolution, I seriously doubt iron was used anywhere as concrete reinforcement simply because Safehold couldn't make lots of iron cheaply. In fact, all the examples given of Safehold using concrete seem to be all examples where reinforcement isn't needed at all, aka canals and roads.

Of course, once Charis' industrial revolution gets going, that's probably going to change.

And IIRC, the only thing we know the Writ says about canals and roads is that it has very exacting standards on their construction. Which sounds more like the quality of the road and canal work, which may or may not include specific composition.

WeberFan wrote:

Keith_w wrote:I don't think the question is "Is someone still produce Iron in the Empire? Would be a waste of material." The question is, when they built or repaired canals before the war, what did they use to reinforce the concrete?

I'm not an expert by any stretch, but two solutions come to mind right away:
- They poured the walls without using any reinforcement / rebar at all. From one of the previous posters - concrete has good compressive strength. So long as the walls are properly backfilled, and the lock walls thick enough, I think they could have gotten away with it.
- They didn't pour the walls at all. Instead, they used concrete as a parge coat over a substrate, most likely dressed stone - like stucco I suppose. In this case, the stone would provide all the strength and the concrete / cement would only be a thick coat used for waterproofing.

This presupposes that ironmaking wasn't advanced enough, and that there wasn't any understanding about reinforcement being required. Given the Proscriptions, I can't see any civil engineering "research" going on. What they did probably came through the Writ and was mandated by the Archangels: "In God's Holy Canals, thou shalt always incorporate iron bars lest Shan Wei destroy thine efforts..."

evilauthor wrote:Prior to Charis' industrial revolution, I seriously doubt iron was used anywhere as concrete reinforcement simply because Safehold couldn't make lots of iron cheaply. In fact, all the examples given of Safehold using concrete seem to be all examples where reinforcement isn't needed at all, aka canals and roads.

Of course, once Charis' industrial revolution gets going, that's probably going to change.

And IIRC, the only thing we know the Writ says about canals and roads is that it has very exacting standards on their construction. Which sounds more like the quality of the road and canal work, which may or may not include specific composition.

Keith_w wrote:Definitely the last part about the Writ. The problem that I thought about when I thought about unreinforced concrete was during the winter when water levels are low, there is no equal pressure on the "inside" of the canal to counteract the external pressure from the earth as it freezes and expands, causing the canal wall to move into the canal. Not that I think that the canal will collapse in a single year, or even a decade, but over the years the damage will build up, springing leaks out and eventually collapse into the canal.

Hildum wrote:

evilauthor wrote:Prior to Charis' industrial revolution, I seriously doubt iron was used anywhere as concrete reinforcement simply because Safehold couldn't make lots of iron cheaply. In fact, all the examples given of Safehold using concrete seem to be all examples where reinforcement isn't needed at all, aka canals and roads.

Of course, once Charis' industrial revolution gets going, that's probably going to change.

And IIRC, the only thing we know the Writ says about canals and roads is that it has very exacting standards on their construction. Which sounds more like the quality of the road and canal work, which may or may not include specific composition.

Well, the Romans used horse hair in their concrete, so there are actually a lot of options. Hair is also used to strengthen mud bricks.

saber964 wrote: quote="Hildum" quote="evilauthor" Prior to Charis' industrial revolution, I seriously doubt iron was used anywhere as concrete reinforcement simply because Safehold couldn't make lots of iron cheaply. In fact, all the examples given of Safehold using concrete seem to be all examples where reinforcement isn't needed at all, aka canals and roads.

Of course, once Charis' industrial revolution gets going, that's probably going to change.

And IIRC, the only thing we know the Writ says about canals and roads is that it has very exacting standards on their construction. Which sounds more like the quality of the road and canal work, which may or may not include specific composition.
/quote


Well, the Romans used horse hair in their concrete, so there are actually a lot of options. Hair is also used to strengthen mud bricks.
/quote


IIRC the Chinese used rice flour in the mortar of the Great Wall that is stronger than the clay bricks. The bricks suffered from erosion while the mortar resisted it better.

Keith_w wrote:
Neat, thanks for pointing those other non-steel choices out.

Maldorian wrote:Steel is the only Metal you can use for reinforced concrete, because of the linear Expansion coefficient.

If the temperature changes, material expand with different rates. Concrete and steel expand with nearby the same rate, so that you can mix it.

Other materials would blow up the concrete if the temperature changes.