Editing Concrete (section)

===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>