Editing Cement (section)

=== Middle Ages ===
Any preservation of this knowledge in literature from the [[Middle Ages]] is unknown, but medieval [[masonry|masons]] and some military engineers actively used hydraulic cement in structures such as [[canal]]s, fortresses, [[harbor]]s, and [[Shipyard|shipbuilding facilities]].<ref name="Sismondo">{{Cite book|last=Sismondo|first=Sergio|url={{google books|plainurl=y|id=LescwF8FBigC}}|title=An Introduction to Science and Technology Studies|date=20 November 2009|publisher=Wiley|isbn=978-1-4443-1512-7|language=en}}</ref><ref name="Mukerji">{{Cite book|last=Mukerji|first=Chandra|url={{google books|plainurl=y|id=fRwNRrFswv8C|page=121}}|title=Impossible Engineering: Technology and Territoriality on the Canal Du Midi|date=2009|page=121|publisher=Princeton University Press|isbn=978-0-691-14032-2|language=en}}</ref> A mixture of lime mortar and aggregate with brick or stone facing material was used in the [[Eastern Roman Empire]] as well as in the West into the [[Gothic architecture|Gothic period]]. The German [[Rhineland]] continued to use hydraulic mortar throughout the Middle Ages, having local pozzolana deposits called [[trass]].<ref name="Cowan 1975"/>