Editing Concrete (section)

===Cement===
{{main|Cement}}
[[File:Stockage de ciments.JPG|thumb|Several tons of bagged cement, about two minutes of output from a 10,000 ton per day [[cement kiln]]]]

Portland cement is the most common type of cement in general usage. It is a basic ingredient of concrete, [[mortar (masonry)|mortar]], and many [[plaster]]s.<ref>{{Cite web|last1=Melander|first1=John M.|last2=Farny|first2=James A.|last3=Isberner|first3=Albert W. Jr. |date=2003|title=Portland Cement Plaster/Stucco Manual|url=https://www.cement.org/docs/default-source/stucco/eb049.pdf?sfvrsn=540de3bf_2|url-status=live|access-date=2021-07-13|website=Portland Cement Association|archive-url=https://web.archive.org/web/20210412174321/https://www.cement.org/docs/default-source/stucco/eb049.pdf?sfvrsn=540de3bf_2 |archive-date=12 April 2021 }}</ref>  It consists of a mixture of calcium silicates ([[alite]], [[belite]]), [[tricalcium aluminate|aluminates]] and [[calcium aluminoferrite|ferrites]]—compounds, which will react with water. Portland cement and similar materials are made by heating [[limestone]] (a source of calcium) with clay or shale (a source of silicon, aluminium and iron) and grinding this product (called ''[[clinker (cement)|clinker]]'') with a source of [[sulfate]] (most commonly [[gypsum]]).

[[Cement kiln]]s are extremely large, complex, and inherently dusty industrial installations. Of the various ingredients used to produce a given quantity of concrete, the cement is the most energetically expensive. Even complex and efficient kilns require 3.3 to 3.6 gigajoules of energy to produce a ton of clinker and then [[Cement mill|grind it into cement]]. Many kilns can be fueled with difficult-to-dispose-of wastes, the most common being used tires. The extremely high temperatures and long periods of time at those temperatures allows cement kilns to efficiently and completely burn even difficult-to-use fuels.<ref>{{cite web|title=Cement Production|url=http://www.iea-etsap.org/web/E-TechDS/PDF/I03_cement_June%202010_GS-gct.pdf|publisher=IEA ETSAP – Energy Technology Systems Analysis Programme|access-date=9 January 2013|author=Evelien Cochez|author2=Wouter Nijs|name-list-style=amp|author3=Giorgio Simbolotti|author4=Giancarlo Tosato|location= |archive-url=https://web.archive.org/web/20130124004654/http://www.iea-etsap.org/web/E-TechDS/PDF/I03_cement_June%202010_GS-gct.pdf|archive-date=24 January 2013}}</ref> The five major compounds of calcium silicates and aluminates comprising Portland cement range from 5 to 50% in weight.