Editing Cement (section)

===18th century===
The technical knowledge for making hydraulic cement was formalized by French and British engineers in the 18th century.<ref name="Sismondo"/>

[[John Smeaton]] made an important contribution to the development of cements while planning the construction of the third [[Eddystone Lighthouse]] (1755–59) in the [[English Channel]] now known as [[Smeaton's Tower]]. He needed a hydraulic mortar that would set and develop some strength in the twelve-hour period between successive high [[tide]]s. He performed experiments with combinations of different [[limestone]]s and additives including trass and [[pozzolana]]s<ref name="Blezard">{{Cite book|editor-last=Hewlett|editor-first=Peter|url={{google books|plainurl=y|id=v1JVu4iifnMC}}|title=Lea's Chemistry of Cement and Concrete|date=12 November 2003|publisher=Elsevier|isbn=978-0-08-053541-8|language=en|last=Blezard|first=Robert G.|chapter=The History of Calcareous Cements|pages=1–24}}</ref> and did exhaustive market research on the available hydraulic limes, visiting their production sites, and noted that the "hydraulicity" of the lime was directly related to the [[clay]] content of the [[limestone]] used to make it. Smeaton was a civil engineer by profession, and took the idea no further.

In the [[Atlantic coastal plain|South Atlantic seaboard]] of the United States, [[Tabby (cement)|tabby]] relying on the oyster-shell [[midden]]s of earlier Native American populations was used in house construction from the 1730s to the 1860s.<ref name="books.google.com"/>

In Britain particularly, good quality building stone became ever more expensive during a period of rapid growth, and it became a common practice to construct prestige buildings from the new industrial bricks, and to finish them with a [[stucco]] to imitate stone. Hydraulic limes were favored for this, but the need for a fast set time encouraged the development of new cements. Most famous was Parker's "[[Roman cement]]".<ref>Francis, A.J. (1977) ''The Cement Industry 1796–1914: A History'', David & Charles. {{ISBN|0-7153-7386-2}}, Ch. 2.</ref> This was developed by [[James Parker (cement maker)|James Parker]] in the 1780s, and finally patented in 1796. It was, in fact, nothing like material used by the Romans, but was a "natural cement" made by burning [[Septarian concretion|septaria]] – [[Nodule (geology)|nodules]] that are found in certain clay deposits, and that contain both [[clay minerals]] and [[calcium carbonate]]. The burnt [[nodule (geology)|nodules]] were ground to a fine powder. This product, made into a mortar with sand, set in 5–15 minutes. The success of "Roman cement" led other manufacturers to develop rival products by burning artificial [[hydraulic lime]] cements of [[clay]] and [[chalk]].
Roman cement quickly became popular but was largely replaced by [[Portland cement]] in the 1850s.<ref name="Blezard"/>