Concrete not lost after the fall of Rome

[Hobelhouse]

In Europe, the techniques to make concrete were lost after the fall of Rome, up until the 17th century. What if the formula had not been lost? How would this have affected architecture and technology?

I imagine it would have had quite a few applications for both of the iconic structures of the Middle Ages, the castle and the cathedral.

 

[Lalli]

Probably on Middle Ages is better roads and then information and troops can move faster. This is of course big effects for history. Wondering how this effect for feodalism. Maybe we see stronger central governments.

 

[LSCatilina]

Probably on Middle Ages is better roads and then information and troops can move faster. This is of course big effects for history. Wondering how this effect for feodalism. Maybe we see stronger central governments.

The roman roads weren't adapted to medieval trade anyway.
They were slowly abandoned because merchants used to carry more stuff and for that using devices that damaged these roads.

A part for the troop movments, they weren't really that used, or only when it was a possibility to maintain them regularly. Furthermore, the dynamic of trade used different pathwats because of
-Town to town trade instead of international one
-New trade centers : the mediterranean cities during the middle-ages (due to Saracanic and Norman raids) lost some importance and places were the romans didn't built road gained some.

For the feudalism, it didn't happen becaus of the lack of ways of trade and army moves. It happened because : weakness of royal power before normans, saracens, slavs, maygars.
Actually, more usable roads would means : invasions more importants due to more easy-made and maintenable roads (the muslims and maygars followed the roman roads to raid) and feudalism maybe so.$

For the troops going faster..i doubt it : the roman roads were adapted to the high-medieval army and a concrete one would have not only necessited a more important investment, but wouldn't have given a real advantage to a mainly cavalry-based army.

And, finally, regarding how concrete was lost...
It's not because we don't have today's remain of concrete that it simply disapperead by magic.
In fact, we have some exemples of concrete building or knowledge of concrete technology before the XVIII and the alleged "re-discovery", such as the De Architectura of Renaissance italy.

During middle ages, we know for certain that pozzolan was used at least since the XIII.

I think it was not "lost" because of a lack of knowledge but because it wasn't adapted to the era : concrete was used for the romans mainly for big monuments that they wanted to last.

Middle-Ages is about a more important modificability of building : they have to be adapted in case of a change of technology : just look at the changes of castles between the XI and XV. It's the sames but adapted.

And for the ressources : it's more easy to use wood and stone directly as it comes. It's what roman did for not monumental architecture.
Furthermore, the medieval era know how to use basic ressources without a more big investment in material : cathedrals of stone or brick are still here today.
They just didn't need concrete, and therefore not used it.

 

[Vitruvius]

I discussed some of the architectural implications in another thread. Some of the other posters made good points about its implications for fortifications and the problems with Roman concrete vs modern concrete, which have some very important differences most notably in the way they are poured/set.

 

[CandyDragon]

I think that concrete really just wasn't what the societies and cultures that developed with the later Empire needed. IIRC, you hear about the decay of the roads at the same time that you hear about the great semi-feudal estates of the Senators. The changes are simply a function of the change in societal structure. It would require a very different impetus for the Middle Ages to keep concrete relevant. IIRC, you see less concrete structures later in the Empire. Dazzling, beautiful buildings, at least in the West, were no longer especially needed, as the ability to survive an increasingly lawless area became more crucial. Cost was also a factor. The cheap, wooden palisades that initially arose were essentially more cost effective, requiring less building materials, and less worker expertise. The later castles developed from these palisades upon mounds, not from the Roman forts. Of course, my knowledge is relatively stale when it comes to this topic, and I believe that the palisade and mound castles were largely in Britain... Oh well...

 

[Vitruvius]

I think it was not "lost" because of a lack of knowledge but because it wasn't adapted to the era : concrete was used for the romans mainly for big monuments that they wanted to last.

Middle-Ages is about a more important modificability of building : they have to be adapted in case of a change of technology : just look at the changes of castles between the XI and XV. It's the sames but adapted.

And for the ressources : it's more easy to use wood and stone directly as it comes. It's what roman did for not monumental architecture.
Furthermore, the medieval era know how to use basic ressources without a more big investment in material : cathedrals of stone or brick are still here today.
They just didn't need concrete, and therefore not used it.

Romans had a mixed use of concrete in civic architecture that was more dependent upon tradition than any practical concerns. As I noted in the other thread some Roman building types, mostly those involved in government or religious ceremony, were extremely conservative in design and style. The typology of a Roman (civic) basilica for example was extremely conservative. Take the Basilica Ulpia for example. The basilica retained the traditional post and lintel stone construction of Greek columnar architecture when the Romans were perfectly capable of building large concrete vaulted halls, as evidenced by Trajan's Market built contemporaneously on the Quirinal next to the Forum or by the Pantheon built only a few decades later. Furthermore the construction of the Forum of Trajan necessitated the removal of a large portion of the Quirinal Hill, allegedly to the height of the Column of Trajan, so clearly it was a major building involving a huge undertaking in manpower and resources. Yet it was deliberately built in an 'older' style and did not take advantage of Roman concrete.

It is only towards the 4th century that concrete begins to appear in Roman civic and religious buildings. The Basilica of Maxentius and Constantine essentially borrows the typology of the Roman bath instead of drawing upon the traditional Greek columnar hall. You see a lot of other interesting choices, like the arched colonnade in the Palace of Diocletian - the final synthesis of the Roman arch and the Greek columnar orders, appearing around the same time. Basically conventions were breaking down mirroring the chaotic state of the Empire.

You do have a point in that pure stone would be easier for a medieval people to use in that it didn't require the same level of logistical or technical capabilities. Roman concrete required a certain level of engineering knowledge, about how to calculate aggregate sizes and mixtures and the placement of brick reinforcement arches for example, that went beyond the mere formulation of the concrete itself. It also required a high degree of man power. Roman concrete wasn't quite the same as the modern stuff. It was 'thicker' and applied more like mortar than poured like modern concrete. So in the Pantheon, for example, it was hand applied by workmen by the bucket load and large pieces of aggregate, pumice or sometimes pottery, were hand placed into it rather than mixed. This had to be done in a continuous process, since it was like modern concrete in that it had to be done in one pour or in this case one 'set'. That kind of operation especially for a large building would be beyond the capabilities or specialized knowledge of medieval societies. Medieval Cathedrals we're built over decades or sometimes centuries. The dome of the Pantheon had to be built in one continuous 24/7 application of concrete until complete.

Then we return to conventions. Christian churches adopted the typology of the Roman civic basilica when the church received official recognition. Thus christian churches adopted the central aisle and side aisles with a columnar screen. Vaulting didn't really even enter into the equation until about Justinian and even then never really displaced the basilica type except in the Byzantine Empire. And you don't really need concrete to build a basilica, as the Romans clearly showed us. Since churches were the main monumental building in most medieval communities there was little impetus to build buildings in concrete when stone or brick would suffice. Combined with a decline in resources and specialization concrete construction quickly fell by the wayside.

 

[LSCatilina]

Yes i mostly agree with that, except with the supposed decline of ressources and specialization.

As you pointed many roman architectural features were about tradition, and after the fall of their Empire, local populations used back local traditions particularly in Gaul were celtics uses reappered (mainly confused with german ones).

For the monumental architecture in the western world, i wouldn't say that churches and cathedrals are the only ones : we have unfortunatly lost many palaces of pre-1100 era because they were destroyed by post-carolingian invasion or reused.

Again, this is the main point of all medieval monumental architecture : it have to be remade if needed. Why we have so many churches and cathedrals remaining mostly of one style?
Because it was an huge thing, hard to be modified without be razed and even there it's need an awful time and ammount of money to finish the building.

So it wasn't just interesting to make it modifiable : at the contrary of civil architecture. Castles, palaces, fortress of early middle-ages are today mainly lost in their original state because they are modified in order to be adapted of new needs.

It's the principal difference with the roman architecture which is supposed to be put into a tradition : medieval one is an utilitarian one.