Editing Concrete (section)

==History==
===Ancient times===
Concrete floors were found in the royal palace of [[Tiryns]], Greece, which dates roughly to 1400 to 1200 BC.<ref>{{cite book|author1=Heinrich Schliemann|author2=Wilhelm Dörpfeld|author3=Felix Adler|title=Tiryns: The Prehistoric Palace of the Kings of Tiryns, the Results of the Latest Excavations|url=https://archive.org/details/bub_gb_pw4BAAAAMAAJ|year=1885|publisher=Charles Scribner's Sons|location=New York|pages=[https://archive.org/details/bub_gb_pw4BAAAAMAAJ/page/n266 190], 203–204, 215}}</ref><ref>{{cite arXiv|first =Amelia Carolina|last = Sparavigna|title = Ancient concrete works|eprint= 1110.5230|class = physics.pop-ph|year = 2011}}</ref> Lime mortars were used in Greece, such as in Crete and Cyprus, in 800 BC. The [[Assyria]]n Jerwan Aqueduct (688 BC) made use of [[waterproof concrete]].<ref>Jacobsen T and Lloyd S, (1935) "Sennacherib's Aqueduct at Jerwan," ''Oriental Institute Publications'' 24, Chicago University Press</ref> Concrete was used for construction in many ancient structures.<ref>{{Cite journal|title=Ancient Concrete Structures|author=Stella L. Marusin|journal=Concrete International|volume=18|issue=1|pages=56–58|date=1 January 1996|url= https://www.concrete.org/publications/internationalconcreteabstractsportal/m/details/id/9377}}</ref>

Mayan concrete at the ruins of [[Uxmal]] (AD 850–925) is referenced in ''Incidents of Travel in the Yucatán'' by [[John Lloyd Stephens|John L. Stephens]]. "The roof is flat and had been covered with cement". "The floors were cement, in some places hard, but, by long exposure, broken, and now crumbling under the feet." "But throughout the wall was solid, and consisting of large stones imbedded in mortar, almost as hard as rock."

Small-scale production of concrete-like materials was pioneered by the [[Nabataea|Nabatean]] traders who occupied and controlled a series of oases and developed a small empire in the regions of southern Syria and northern Jordan from the 4th century BC. They discovered the advantages of [[hydraulic lime]], with some self-cementing properties, by 700 BC. They built [[kiln]]s to supply mortar for the construction of [[rubble masonry]] houses, concrete floors, and underground waterproof [[cistern]]s. They kept the cisterns secret as these enabled the Nabataeans to thrive in the desert.<ref name="Gromicko-2016">{{Cite web|url=https://www.nachi.org/history-of-concrete.htm |title=The History of Concrete |last1=Gromicko|first1=Nick|last2=Shepard|first2=Kenton|date=2016|website=International Association of Certified Home Inspectors, Inc.|access-date=27 December 2018}}</ref> Some of these structures survive to this day.<ref name="Gromicko-2016" />

In the [[Ancient Egypt]]ian and later [[Roman Empire|Roman]] eras, builders discovered that adding [[Pozzolan|volcanic ash]] to [[Lime (material)|lime]] allowed the mix to set underwater. They discovered the [[Pozzolanic activity#Reaction|pozzolanic reaction]].<ref>{{Cite web |date=2023-01-06 |title=Riddle solved: Why was Roman concrete so durable? |url=https://news.mit.edu/2023/roman-concrete-durability-lime-casts-0106 |access-date=2024-10-25 |website=MIT News {{!}} Massachusetts Institute of Technology |language=en}}</ref>

===Classical era===
[[File:Rome (Italy, October 2019) - 275 (50589571796).jpg|thumb|Exterior of the [[Roman Pantheon]], finished 128 AD, the largest unreinforced concrete [[dome]] in the world.<ref>{{Cite web |title=Roman Concrete Research |first=David |last=Moore |url=http://www.romanconcrete.com/ |access-date=2022-08-13 |archive-url=https://web.archive.org/web/20141006012615/http://www.romanconcrete.com/|url-status=live |date=6 October 2014 |website= Romanconcrete.com|archive-date=6 October 2014 }}</ref>]]
[[File:Pantheon (Rome) - Dome.jpg|thumb|Interior of the Pantheon dome, seen from beneath. The concrete for the [[coffer]]ed dome was laid on moulds, mounted on temporary scaffolding.]]
[[File:Museo Foro Caesaragusta - Cloaca del foro 03.JPG|thumb|upright|''[[Opus caementicium]]'' exposed in a characteristic Roman arch. In contrast to modern concrete structures, the concrete used in Roman buildings was usually covered with brick or stone.]]

The Romans used concrete extensively from 300 BC to AD 476.<ref name=MAST>{{cite web|title=The History of Concrete|url=http://matse1.matse.illinois.edu/concrete/hist.html|publisher=Dept. of Materials Science and Engineering, University of Illinois, Urbana-Champaign|access-date=8 January 2013|url-status=live|archive-url=https://web.archive.org/web/20121127052951/http://matse1.matse.illinois.edu/concrete/hist.html|archive-date=27 November 2012}}</ref> During the Roman Empire, [[Roman concrete]] (or ''[[opus caementicium]]'') was made from [[quicklime]], [[pozzolana]] and an aggregate of [[pumice]].<ref>{{Cite book |last=Chiu |first=Y. C. |url=https://books.google.com/books?id=osNrPO3ivZoC&dq=During+the+Roman+Empire,+Roman+concrete+(or+opus+caementicium)+was+made+from+quicklime,+pozzolana+and+an+aggregate+of+pumice.&pg=PA50 |title=An Introduction to the History of Project Management: From the Earliest Times to A.D. 1900 |date=2010 |publisher=Eburon Uitgeverij B.V. |isbn=978-90-5972-437-2 |pages=50 |language=en}}</ref> Its widespread use in many [[Architecture of ancient Rome|Roman structures]], a key event in the [[history of architecture]] termed the [[Roman architectural revolution]], freed [[Roman engineering|Roman construction]] from the restrictions of stone and brick materials. It enabled revolutionary new designs in terms of both structural complexity and dimension.<ref>{{Cite book| last = Lancaster| first = Lynne| title = Concrete Vaulted Construction in Imperial Rome. Innovations in Context| publisher=Cambridge University Press| date = 2005| isbn = 978-0-511-16068-4}}</ref> The [[Colosseum]] in Rome was built largely of concrete, and the [[Pantheon, Rome|Pantheon]] has the world's largest unreinforced concrete dome.<ref>{{cite web |url=http://www.romanconcrete.com/docs/chapt01/chapt01.htm |title=The Pantheon |first=David |last=Moore |work=romanconcrete.com |date=1999 |access-date=26 September 2011 |url-status=live |archive-url=https://web.archive.org/web/20111001052926/http://www.romanconcrete.com/docs/chapt01/chapt01.htm |archive-date=1 October 2011  }}</ref>

<blockquote>Concrete, as the Romans knew it, was a new and revolutionary material. Laid in the shape of [[arch]]es, [[Vault (architecture)|vaults]] and [[List of Roman domes|domes]], it quickly hardened into a rigid mass, free from many of the internal thrusts and strains that troubled the builders of similar structures in stone or brick.<ref>D.S. Robertson (1969). ''Greek and Roman Architecture'', Cambridge, p. 233</ref></blockquote>

Modern tests show that ''opus caementicium'' had a similar compressive strength to modern Portland-cement concrete (c. {{convert|200|kg/cm2|MPa psi|abbr=on|disp=sqbr}}).<ref>{{Cite book |last=Cowan |first=Henry J. |title=The master builders: a history of structural and environmental design from ancient Egypt to the nineteenth century |date=1977 |publisher=Wiley |isbn=0-471-02740-5 |location=New York |oclc=2896326}}</ref> However, due to the absence of reinforcement, its [[Ultimate tensile strength|tensile strength]] was far lower than modern [[reinforced concrete]], and its mode of application also differed:<ref>{{Cite web|url=http://www.ce.memphis.edu/1101/notes/concrete/section_2_history.html|archive-url=https://web.archive.org/web/20170227213256/http://www.ce.memphis.edu/1101/notes/concrete/section_2_history.html|title=CIVL 1101|archive-date=27 February 2017|website=www.ce.memphis.edu}}</ref>

<blockquote>Modern structural concrete differs from Roman concrete in two important details. First, its mix consistency is fluid and homogeneous, allowing it to be poured into forms rather than requiring hand-layering together with the placement of aggregate, which, in Roman practice, often consisted of [[rubble]]. Second, integral reinforcing steel gives modern concrete assemblies great strength in tension, whereas Roman concrete could depend only upon the strength of the concrete bonding to resist tension.<ref>Robert Mark, Paul Hutchinson: "On the Structure of the Roman Pantheon", ''Art Bulletin'', Vol. 68, No. 1 (1986), p. 26, fn. 5</ref></blockquote>

The long-term durability of Roman concrete structures was found to be due to the presence of [[Pyroclastic rock|pyroclastic]] (volcanic) rock and ash in the concrete mix. The crystallization of [[strätlingite]] (a complex calcium aluminosilicate hydrate)<ref>{{cite journal |doi = 10.1111/j.1151-2916.1995.tb08910.x|title = 29Si and27Al MASNMR Study of Stratlingite|journal = Journal of the American Ceramic Society |volume = 78|issue = 7|pages = 1921–1926|year = 1995|last1 = Kwan|first1 = Stephen|last2 = Larosa|first2 = Judith |last3=Grutzeck |first3= Michael W.}}</ref> during the formation of the concrete and its merging with similar calcium–aluminium-silicate–hydrate structures helped give the Roman concrete a greater degree of fracture resistance compared to modern concrete.<ref>{{cite journal|title=Mechanical resilience and cementitious processes in Imperial Roman architectural mortar|first1=Marie D.|last1=Jackson|first2=Eric N.|last2=Landis|first3=Philip F.|last3=Brune|first4=Massimo|last4=Vitti|first5=Heng|last5=Chen|first6=Qinfei|last6=Li|first7=Martin|last7=Kunz|first8=Hans-Rudolf|last8=Wenk|first9=Paulo J. M.|last9=Monteiro|first10=Anthony R.|last10=Ingraffea|date=30 December 2014|journal=PNAS|volume=111|issue=52|pages=18484–18489|doi=10.1073/pnas.1417456111|pmid=25512521|pmc=4284584|bibcode = 2014PNAS..11118484J|doi-access=free}}</ref> In addition, Roman concrete is significantly more resistant to erosion by seawater than modern concrete; the aforementioned pyroclastic materials react with seawater to form Al-[[tobermorite]] crystals over time.<ref>{{cite journal|periodical=American Mineralogist|title=Phillipsite and Al-tobermorite mineral cements produced through low-temperature water-rock reactions in Roman marine concrete|volume=102|issue=7|pages=1435–1450 |author1=Marie D. Jackson |author2=Sean R. Mulcahy |author3=Heng Chen |author4=Yao Li |author5=Qinfei Li |author6=Piergiulio Cappelletti |author7=Hans-Rudolf Wenk |date=3 July 2017 |bibcode=2017AmMin.102.1435J|doi=10.2138/am-2017-5993CCBY|s2cid=53452767|url=https://cedar.wwu.edu/geology_facpubs/67|doi-access=free }}</ref><ref>{{cite news|url=https://www.telegraph.co.uk/science/2017/07/03/secret-roman-concrete-survived-tidal-battering-2000-years-revealed/|title=Secret of how Roman concrete survived tidal battering for 2,000 years revealed|url-status=live|archive-url=https://web.archive.org/web/20170704011801/http://www.telegraph.co.uk/science/2017/07/03/secret-roman-concrete-survived-tidal-battering-2000-years-revealed/ |work=The Telegraph|date=3 July 2017|archive-date=4 July 2017|last1=Knapton|first1=Sarah}}</ref> The use of hot mixing in preparation of concrete, leading to the formation of lime clasts in the final product, has been proposed to give the Roman concrete a [[Self-healing concrete|self-healing ability]].<ref>{{cite journal |last1=Seymour |first1=Linda M. |last2=Maragh |first2=Janille |last3=Sabatini |first3=Paolo |last4=Di Tommaso |first4=Michel |last5=Weaver |first5=James C. |last6=Masic |first6=Admir |title=Hot mixing: Mechanistic insights into the durability of ancient Roman concrete |journal=Science Advances |date=6 January 2023 |volume=9 |issue=1 |pages=eadd1602 |doi=10.1126/sciadv.add1602 |pmc=9821858 |pmid=36608117 |bibcode=2023SciA....9D1602S }}</ref><ref>{{Cite web |last=Starr |first=Michelle |date=2024-02-01 |title=We Finally Know How Ancient Roman Concrete Was Able to Last Thousands of Years |url=https://www.sciencealert.com/we-finally-know-how-ancient-roman-concrete-was-able-to-last-thousands-of-years |access-date=2024-02-01 |website=ScienceAlert |language=en-US}}</ref>

The widespread use of concrete in many Roman structures ensured that many survive to the present day. The [[Baths of Caracalla]] in Rome are just one example. Many [[Roman aqueduct]]s and bridges, such as the magnificent [[Pont du Gard]] in southern France, have masonry cladding on a concrete core, as does the dome of the [[Pantheon, Rome|Pantheon]].

===Middle Ages===
After the Roman Empire, the use of burned lime and pozzolana was greatly reduced. Low kiln temperatures in the burning of lime, lack of pozzolana, and poor mixing all contributed to a decline in the quality of concrete and mortar. From the 11th century, the increased use of stone in church and [[castle]] construction led to an increased demand for mortar. Quality began to improve in the 12th century through better grinding and sieving. Medieval lime mortars and concretes were non-hydraulic and were used for binding masonry, "hearting" (binding [[rubble masonry]] cores) and foundations. [[Bartholomaeus Anglicus]] in his ''De proprietatibus rerum'' (1240) describes the making of mortar. In an English translation from 1397, it reads "lyme ... is a stone brent; by medlynge thereof with sonde and water sement is made". From the 14th century, the quality of mortar was again excellent, but only from the 17th century was pozzolana commonly added.<ref>Peter Hewlett and Martin Liska (eds.), ''Lea's Chemistry of Cement and Concrete'', 5th ed. (Butterworth-Heinemann, 2019), pp. 3–4.</ref>

The ''[[Canal du Midi]]'' was built using concrete in 1670.<ref>{{cite book |last1=Rassia |first1=Stamatina Th |last2=Pardalos |first2=Panos M. |title=Cities for Smart Environmental and Energy Futures: Impacts on Architecture and Technology |date=15 August 2013 |publisher=Springer Science & Business Media |isbn=978-3-642-37661-0 |page=58 |url={{google books|plainurl=y|id=vFu6BAAAQBAJ|page=58}} |language=en}}</ref>

===Industrial era===
[[File:Smeaton's Lighthouse00.jpg|thumb|upright|[[Smeaton's Tower]] in [[Devon]], England]]

Perhaps the greatest step forward in the modern use of concrete was [[Smeaton's Tower]], built by British engineer [[John Smeaton]] in [[Devon]], England, between 1756 and 1759. This third [[Eddystone Lighthouse]] pioneered the use of [[hydraulic lime]] in concrete, using pebbles and powdered brick as aggregate.<ref name=InterNACHI>{{cite web|title=the History of Concrete|url=http://www.nachi.org/history-of-concrete.htm|publisher=The International Association of Certified Home Inspectors (InterNACHI)|author=Nick Gromicko|author2=Kenton Shepard|name-list-style=amp|access-date=8 January 2013|url-status=live|archive-url=https://web.archive.org/web/20130115151648/http://www.nachi.org/history-of-concrete.htm|archive-date=15 January 2013}}</ref>

A method for producing [[Portland cement]] was developed in England and patented by [[Joseph Aspdin]] in 1824.<ref>{{cite web|last=Herring|first=Benjamin|title=The Secrets of Roman Concrete|url=http://www.romanconcrete.com/Article1Secrets.pdf|publisher=Romanconcrete.com|access-date=1 October 2012|url-status=live|archive-url=https://web.archive.org/web/20120915054736/http://www.romanconcrete.com/Article1Secrets.pdf|archive-date=15 September 2012}}</ref> Aspdin chose the name for its similarity to [[Portland stone]], which was quarried on the [[Isle of Portland]] in [[Dorset]], England. His son [[William Aspdin|William]] continued developments into the 1840s, earning him recognition for the development of "modern" Portland cement.<ref>{{cite book|last1=Courland|first1=Robert|title=Concrete planet: the strange and fascinating story of the world's most common man-made material|date=2011|publisher=Prometheus Books|location=Amherst, NY|isbn=978-1-61614-481-4|url={{google books|plainurl=y|id=qRcwAQAAQBAJ|page=190}}|access-date=28 August 2015|url-status=live|archive-url=https://web.archive.org/web/20151104111744/https://books.google.com/books?id=qRcwAQAAQBAJ&pg=PT190|archive-date=4 November 2015}}</ref>

[[Reinforced concrete]] was invented in 1849 by [[Joseph Monier]].<ref>{{Cite web |title=The History of Concrete and Cement |url=https://www.thoughtco.com/history-of-concrete-and-cement-1991653 |website=ThoughtCo |language=en|date=9 April 2012 |access-date=2022-08-13}}</ref> and the first reinforced concrete house was built by François Coignet<ref name="britannia">{{cite web |url=https://www.britannica.com/EBchecked/topic/124672/Francois-Coignet |title=Francois Coignet – French house builder |access-date=23 December 2016}}</ref> in 1853.
The first concrete reinforced bridge was designed and built by [[Joseph Monier]] in 1875.<ref>« Château de Chazelet » [archive], notice no PA00097319, base Mérimée, ministère français de la Culture.</ref>

[[Prestressed concrete]] and [[Prestressed concrete#Post-tensioned concrete|post-tensioned concrete]] were pioneered by [[Eugène Freyssinet]], a French  [[structural engineer|structural]] and [[civil engineer]]. Concrete components or structures are compressed by tendon cables during, or after, their fabrication in order to strengthen them against [[Tension (physics)|tensile]] forces developing when put in service. Freyssinet [[patent]]ed the technique on 2 October 1928.<ref name="Billington1985">{{cite book| last = Billington| first = David| title = The Tower and the Bridge| publisher = Princeton University Press| location = Princeton| year = 1985| isbn = 0-691-02393-X| url = https://archive.org/details/towerbridgenewar00bill}}</ref>