WI: concrete technology never lost?

For unknown reasons, Roman concrete making technology became completely unknown during the Dark Ages. Was it still in use in the Eastern Empire? During the Middle Ages, Western European construction were stone based. Concrete wasn't reinvented until the Renaissance.

It seems bizzare something so simple could be lost when stone age societies like the Mayans were able to preserve their concrete making process. What if the knowlege was retained, how different would architecture and fortification be?
 

Vitruvius

Donor
Roman concrete isn't perfectly suited for the architectonics of Gothic but then again Gothic as we know if will probably never develop due to butterflies (it emerged as a local variation of Romanesque within the Ile de France). I would expect larger but not necesarily taller interior volumes. For example the late Roman Basilica of Maxentius and Constantine which was largely based on the typology of a Roman bath. If that could continue and be used in Early Christian buildings then expect massive concrete vaulted halls for the faithful to assemble and worship.

But its hard to say. Roman civic architecture was remarkably conservative in style. They were sill building civic basilicas with flat timbered roofs and colonnades when they were perfectly capable of building massive concrete vaulted spaces, which you see in the baths. Aside from the Pantheon most major temples were like wise conservative pseudo-peripteral structures. It was only late in the Empire as traditions were breaking down (and technology was being lost) that you see more experimentation like Diocletion's Palace or Maxentius & Constantine.

Infrastructure would be greatly affected not just in fortifications but in retaining walls, aqueducts, cisterns etc. Then again it doesn't mean those things would be built just that there is the potential to build them on a greater scale. Also there's a lot of associated technology and know how that needs to be maintained to build the largest structures. The Pantheon for example is not just a big concrete dome but incorporates a careful layering a precise concentrations of aggregate (fine ground light weight pumice in at the top, larger dense stones towards the botton) to maximize weight and strength. It also needed a large amount of scaffolding to support the dome while it was being constructed. Another key to any Roman concrete structure was brick reinforcing, such as the brick relieving arches built into the walls of the Pantheon.

So ultimately the affects of surviving concrete technology will depend upon how much associated engineering knowledge survives as well as the logistical capabilities of the society in question. Without the knowledge of aggregates weight will become an issue and will limit fenestration ie def no concrete 'Gothic'. Same goes for brick reinforcement. And without the man power large projects are questionable - remember concrete has to be set continuously, its not like laying bricks or stone it can't be done one piece at a time start and stop.
 
Roman concrete isn't perfectly suited for the architectonics of Gothic but then again Gothic as we know if will probably never develop due to butterflies (it emerged as a local variation of Romanesque within the Ile de France). I would expect larger but not necesarily taller interior volumes. For example the late Roman Basilica of Maxentius and Constantine which was largely based on the typology of a Roman bath. If that could continue and be used in Early Christian buildings then expect massive concrete vaulted halls for the faithful to assemble and worship.

But its hard to say. Roman civic architecture was remarkably conservative in style. They were sill building civic basilicas with flat timbered roofs and colonnades when they were perfectly capable of building massive concrete vaulted spaces, which you see in the baths. Aside from the Pantheon most major temples were like wise conservative pseudo-peripteral structures. It was only late in the Empire as traditions were breaking down (and technology was being lost) that you see more experimentation like Diocletion's Palace or Maxentius & Constantine.

Infrastructure would be greatly affected not just in fortifications but in retaining walls, aqueducts, cisterns etc. Then again it doesn't mean those things would be built just that there is the potential to build them on a greater scale. Also there's a lot of associated technology and know how that needs to be maintained to build the largest structures. The Pantheon for example is not just a big concrete dome but incorporates a careful layering a precise concentrations of aggregate (fine ground light weight pumice in at the top, larger dense stones towards the botton) to maximize weight and strength. It also needed a large amount of scaffolding to support the dome while it was being constructed. Another key to any Roman concrete structure was brick reinforcing, such as the brick relieving arches built into the walls of the Pantheon.

So ultimately the affects of surviving concrete technology will depend upon how much associated engineering knowledge survives as well as the logistical capabilities of the society in question. Without the knowledge of aggregates weight will become an issue and will limit fenestration ie def no concrete 'Gothic'. Same goes for brick reinforcement. And without the man power large projects are questionable - remember concrete has to be set continuously, its not like laying bricks or stone it can't be done one piece at a time start and stop.

Good points. In this context, it's instructive to point out the knowledge of concrete need not result in any engineering and architectural advancements. As pointed out by the original poster, the Maya also made and used concrete. But they made little use of their concrete other than to pave surfaces and as a more permanent analog to mortar and stucco in traditional stone on stone masonry. Everything the Maya built could have been built without concrete. While the Maya artists and architects could design beautiful and impressive architecture, all of it was based essentially on piling up rubble, stone, stucco and concrete facing, stone on stone techniques, and lots of manpower. "Engineering" in the Greco-Roman sense did not exist.
 

Vitruvius

Donor
Giving it more thought I thinks its possible that if the knowledge of concrete was retained in a very basic way and used only in a limited fashion through the middle ages it might provide an interesting foundation for Renaissance innovation. I could see Brunelleschi building the Duomo in Florence with concrete, or Alberti's Sant'Andrea in Mantova with a huge concrete barrel vault. It could also be useful in construction the large bastions of Renaissance fortifications. Renaissance architects made extensive studies of Roman ruins and men like Brunelleschi were make great advances in engineering so its possible they could rediscover Roman construction methods if they are at least familiar with producing and using concrete already. But I still can't see significant architectural use of concrete pre-Renaissance without fundamental changes in Medieval societies, ie retaining a lot more knowledge and advanced civil society.
 
A truly fascinating thread and I'd like to thank everyone who has posted in it, especially Vitruvius.

Thank you all again.
 
Medieval siege warfare would be radically different from OTL. Rome's city walls in the middle ages were built in the days of the Empire, and held for more than a thousand years. Some parts of them can still be seen today. Not surprising, as they were 10 meters wide concrete walls... nigh impossible to break through with contemporary siege engines.
Of course, such fortifications have to be big to be effective: in small castles tipical in the Dark Ages, wooden palisades, stone walls and earthworksworks is still cheaper to build, and in strategical bottlenecks such as mountain passes, they are justified becouse bringing siege engines there is freaking difficult.
But in general, wealthy cities would be bigger with stronger walls, and would accumulate much more influence much earlier than OTL.
 
I had a vague idea that Roman concrete was a mix of materials found locally in Italy, including things like volcanic ash or pumice or something similar. Did the Romans use concrete in places like Britain, which is a bit light on for volcanoes, or more conventional stone, brick and mortar construction?
 
I had a vague idea that Roman concrete was a mix of materials found locally in Italy, including things like volcanic ash or pumice or something similar. Did the Romans use concrete in places like Britain, which is a bit light on for volcanoes, or more conventional stone, brick and mortar construction?

Well the Hagia Sophia in Constantinople used concrete. Does anyone know if the Eastern Empire continued concrete construction after the fall of Rome?

Even basic concrete techniques could be used to build roads and reinforce walls. Perhaps Medieval commerce would get a boost while strengthened walls would maintain Feudalism a little longer from the threat of cannons?
 
Well the Hagia Sophia in Constantinople used concrete. Does anyone know if the Eastern Empire continued concrete construction after the fall of Rome?

Even basic concrete techniques could be used to build roads and reinforce walls. Perhaps Medieval commerce would get a boost while strengthened walls would maintain Feudalism a little longer from the threat of cannons?

I'm thinking of a stronger Hansa whose member cities find themselves virtually impregnable to the advances of greedy kings, particularly when reinforcement and resupply can come by sea.
 
Medieval siege warfare would be radically different from OTL. Rome's city walls in the middle ages were built in the days of the Empire, and held for more than a thousand years. Some parts of them can still be seen today. Not surprising, as they were 10 meters wide concrete walls... nigh impossible to break through with contemporary siege engines.
Of course, such fortifications have to be big to be effective: in small castles tipical in the Dark Ages, wooden palisades, stone walls and earthworksworks is still cheaper to build, and in strategical bottlenecks such as mountain passes, they are justified becouse bringing siege engines there is freaking difficult.

But in general, wealthy cities would be bigger with stronger walls, and would accumulate much more influence much earlier than OTL.
Close to my thoughts as can be seen in my TL where concrete took off around 1000 AD (because a lot of the Roman documents that were lost over the years were copied and saved by the Alt-Spaniards). Cities retain a lot more power and the politics regarding them is dominated by power sharing agreements in general with the nobility always always always based in a city. In Spain itself the nobility are essentially the leader of the city council/royal representative.
 
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Oddball

Monthly Donor
Early concrete have one crucial weakeness:

It lacks the modern adition of reinforcement. One of the reasons that concrete is so useful is the adding of steel (or other material) reinforcing bars. Concrete is strong in carrying compressing load, but very weak to tension load.

I have a sneaky suspicion that this will reneder concrete less practical to use than you hope, before the industrial revolution and large scale production of a reinforcing methode.

[/ engineering rant] :eek::D
 
I would wager stonemasons lose some of their prestige, or better yet share it with the "Mixers"... the stirers of the pot!
 
I had a vague idea that Roman concrete was a mix of materials found locally in Italy, including things like volcanic ash or pumice or something similar. Did the Romans use concrete in places like Britain, which is a bit light on for volcanoes, or more conventional stone, brick and mortar construction?


Actually, that was the problem. The Roman recipe for concrete involved a certain kind of sand only found near Mt. Vesuvius. Once the Empire fell, it became more and more expensive to ship it. It didn't help that the Byzantines, who normally controlled the area, weren't too keen on anyone else getting their hands on it. Which means that while quite a few architects and builders had access to the recipe itself, any attempt to reproduce it led to a soupy mess that would never work.
 
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