𝕸 Construction - large, small

Aqueducts and Underground Passages of Exeter ..
Arundel Castle ..
Battleship - 18th C ..
Bauen wie im Mittelalter ..
Brochs - Scotland ➧
Castles - medieval ..

Destruction 

Transport
Handcart .. 

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Aqueducts and Underground Passages of Exeter

Aqueducts and Underground Passages of Exeter

Underneath the streets of the English city of Exeter their lies a network of medieval tunnels. For hundreds of years they were used to bring fresh drinking-water to the city.

Following the lead of the city of London, Exeter had lead pipes bringing water from a natural spring into the public fountains in the centre of the town. However, by the fourteenth-century the pipes were springing leaks and need to be dug up so much that the citizens decided to build a system of underground tunnels where the pipes could be placed.

http://www.medievalists.net/2014/06/medieval-plumbers-exeter/
https://www.youtube.com/watch?v=jT4SrBjjrog

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Arundel Castle

https://www.youtube.com/watch?v=Abb6KVNj_RU .
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Bauen wie im Mittelalter

https://www.youtube.com/watch?v=u6NI66rrktc .

In Meßkirch nahe dem Bodensee soll eine komplette mittelalterliche Klosteranlage entstehen. Ohne moderne Maschinen und Strom - so, wie im Mittelalter. Ein gigantischer Feldversuch, den wir die ersten drei Jahre begleitet haben. Mehr zur Geschichte im Südwesten:

In Meßkirch near Lake Constance a complete medieval monastery complex is to be built. Without modern machines and electricity - as in the Middle Ages. A gigantic field trial that we accompanied for the first three years. More about the history in the southwest


SWR-Kanal abonnieren unter http://bit.ly/ySWR
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Castles - Secrets of the Castle & Château Guédelon


Castles - medieval ..
Castles - Secrets of the Castle & Château Guédelon ..

Secrets of the Castle playlist:

Guédelon

Photos:
Guédelon Castle – New Medieval Chateau Rises in France.

Châteaux Guédelon links .
posted by mediea
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Castles - medieval

Guédelon > .
S Guédelon - 25 years to build 13th C castle with period tools - Kirsten > .
Ludlow Castle, Shropshire - mortar & building techniques - HiHi > .

Brochs - Scotland ➧

 Guédelon and medieval castles
https://www.youtube.com/watch?v=CboJzrDhoSk

[Medieval] Castles - Functions & Characteristics (1000-1300) - MHV
https://www.youtube.com/watch?v=QhzsM2SFoeQ
Medieval Castles - Elements of Fortifications
https://www.youtube.com/watch?v=IghzU9Dr6VU

Secrets of the Castle - Guédelon documentary, Caerphilly, Conwy, Kenilworth - siege engines - BBC, Battle Castle - archanth
https://www.youtube.com/playlist?list=PLrYzzr8yja6Fv4glws0Sqf3GBLXL_El8W

Medieval Warfare: Castles of War
https://www.youtube.com/playlist?list=PLCpYM0jg1d5OpPWcTwIxVsz6F4JJxWFnr

 Harlech Castle, Wales .. 

Torsion siege engine
https://en.wikipedia.org/wiki/Torsion_siege_engine
Siege engine
https://en.wikipedia.org/wiki/Siege_engine

What are the tactical advantages of a trebuchet over a catapult, and vice versa?
https://www.quora.com/What-are-the-tactical-advantages-of-a-trebuchet-over-a-catapult-and-vice-versa .

Siege Tower ➧   

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Cement & Pozzolans

Medieval Skyscrapers - Ancient Inventions > .
Early European Technology - arch >> .
Cement: A Really Hard Problem - ScSh > .
Ludlow Castle, Shropshire - mortar & building techniques - HiHi > .

Pompēiānī recycled construction materials .

It is uncertain where it was first discovered that a combination of hydrated non-hydraulic lime and a pozzolan produces a hydraulic mixture (see also: Pozzolanic reaction), but concrete made from such mixtures was first used on a large scale by Roman engineers. They used both natural pozzolans (trass or pumice) and artificial pozzolans (ground brick or pottery) in these concretes. Many excellent examples of structures made from these concretes are still standing, notably the huge monolithic dome of the Pantheon in Rome and the massive Baths of Caracalla. The vast system of Roman aqueducts also made extensive use of hydraulic cement.

Although any preservation of this knowledge in literary sources from the Middle Ages is unknown, medieval masons and some military engineers maintained an active tradition of using hydraulic cement in structures such as canals, fortresses, harbors, and shipbuilding facilities. The technical knowledge of making hydraulic cement was later formalized by French and British engineers in the 18th century.

Alite as precursor of silicate phases found in medieval lime mortar

The composition of alite rich in CaO (71.6 wt. %) and relatively poor in SiO2 (25.2 wt. %) (see the hereabove table) may help to understand why in particular conditions, if a sufficiently high temperature is reached in a lime kiln during enough time, alite can also be directly formed by pyrolizing only siliceous limestone (containing amorphous SiO2 impurities up to 25 – 30 wt. %). Hydraulic mortar or pre-Portland cement may have been occasionally produced on a small scale in this way during the medieval epoch in locations where limestone was cemented by amorphous silica or contained chert nodules or a lot of clay impurities.

This is likely the reason why some old medieval lime mortars used to build the Tournai cathedral (Belgium) exhibit an unexpected hydraulic character as revealed by a mineralogical study made by Mertens et al. (2006) who evidenced the presence of wollastonite and rankinite along with CSH phases in lime mortars. The only explanation for the discovery of these silicate phases not normally expected in lime mortar is that they have been formed by the hydration of calcium silicate such as Ca3SiO5 (C3S) or Ca2SiO4 (C2S) formed at high temperature along calcium oxide in the lime kiln. Indeed, in the area of Tournai (Belgium), the Tournaisian limestones are particularly rich in amorphous silica and exploited as building stone and for making lime mortar since very ancient ages. It is presently unknown if the cathedral builders of this area were aware of the hydraulic properties of their lime mortar or intentionally developed its use after their fortuitous finding.

Campi Flegrei Caldera . 
A series of geothermal chemical reactions occurring beneath Italy's Campi Flegrei (near the town of Pozzuoli) is creating lime that then reacts with volcanic pozzolana ash in the caprock to form a concrete-like substance.

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