# Cement chemist notation > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Cement_chemist_notation > Markdown URL: https://mediated.wiki/source/Cement_chemist_notation.md > Source: https://en.wikipedia.org/wiki/Cement_chemist_notation > Source revision: 1284149941 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Abbreviated notation for chemical formulas of common oxides This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages) This article may lack focus or be about more than one topic. Please help improve this article, possibly by splitting it or creating a disambiguation page. Relevant discussion may be found on the talk page. (April 2025) (Learn how and when to remove this message) This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations. (April 2025) (Learn how and when to remove this message) (Learn how and when to remove this message) **Cement chemist notation** (**CCN**) was developed to simplify the [formulas](/source/Formula) [cement](/source/Cement) chemists use on a daily basis. It is a shorthand way of writing the [chemical formula](/source/Chemical_formula) of [oxides](/source/Oxide) of [calcium](/source/Calcium), [silicon](/source/Silicon), and various [metals](/source/Metal). ## Abbreviations of oxides The main oxides present in cement (or in glass and ceramics) are abbreviated in the following way: CCN Actual formula Name C CaO Calcium oxide, or lime S SiO2 Silicon dioxide, or silica A Al2O3 Aluminium oxide, or alumina F Fe2O3 Iron oxide, or rust T TiO2 Titanium dioxide, or titania M MgO Magnesium oxide, or periclase K K2O Potassium oxide N Na2O Sodium oxide H H2O Water C CO2 Carbon dioxide S SO3 Sulfur trioxide P P4O10 Phosphorus pentoxide ## Conversion of hydroxides in oxide and free water For the sake of mass balance calculations, hydroxides present in hydrated phases found in hardened cement paste, such as in [portlandite](/source/Portlandite), Ca(OH)2, must first be converted into oxide and water. To better understand the conversion process of hydroxide anions in oxide and water, it is necessary to consider the autoprotolysis of the [hydroxyl](/source/Hydroxyl) anions; it implies a [proton](/source/Proton) exchange between two OH−, like in a classical [acid–base reaction](/source/Acid%E2%80%93base_reaction): - OH−acid 1 + OH−base 2 → O2−base 1 + H2Oacid 2 or also, - 2 OH− → O2− + H2O For [portlandite](/source/Portlandite) this gives thus the following mass balance: - Ca(OH)2 → CaO + H2O Thus portlandite can be written as CaO · H2O or CH. ## Main phases in Portland cement before and after hydration These oxides are used to build more complex [compounds](/source/Compound_(chemistry)). The main crystalline phases described hereafter are related respectively to the composition of: - Clinker and non-hydrated Portland cement, and; - Hardened cement pastes obtained after hydration and cement setting. ### Clinker and non-hydrated Portland cement Four main phases are present in the [clinker](/source/Clinker_(cement)) and in the non-hydrated Portland [cement](/source/Cement). They are formed at high temperature (1,450 °C) in the [cement kiln](/source/Cement_kiln) and are the following: CCN Actual formula Name Mineral phase C3S 3 CaO · SiO2 Tricalcium silicate Alite C2S 2 CaO · SiO2 Dicalcium silicate Belite C3A 3 CaO · Al2O3 Tricalcium aluminate Aluminate or Celite C4AF 4 CaO · Al2O3 · Fe2O3 Tetracalcium alumino ferrite Ferrite The four compounds referred as C3S, C2S, C3A and C4AF are known as the main crystalline phases of Portland cement. The phase composition of a particular cement can be quantified through a complex set of calculation known as the [Bogue formula](https://en.wikipedia.org/w/index.php?title=Bogue_formula&action=edit&redlink=1). To avoid the flash setting of concrete, due to the very fast hydration of the tricalcium aluminate (C3A), 2–5 wt. % [calcium sulfate](/source/Calcium_sulfate) is interground with the [cement clinker](/source/Cement_clinker) to prepare the [cement](/source/Cement) powder. In cement chemist notation, CaSO4 ([anhydrite](/source/Anhydrite)) is abbreviated as CS, and CaSO4·2H2O ([gypsum](/source/Gypsum)) as CSH2. Similarly, in case of a [limestone](/source/Limestone) filler addition, CaCO3, or CaO·CO2, can be noted CC. ### Hydrated cement paste [Hydration](/source/Hydration_reaction) products formed in hardened cement pastes (also known as HCPs) are more complicated, because many of these products have nearly the same formula and some are solid solutions with overlapping formulas. Some examples are given below: CCN Actual formula Name or mineral phase CH Ca(OH)2 or CaO · H2O Calcium hydroxide (portlandite) C-S-H 0.6–2.0 CaO · SiO2 · 0.9–2.5 H2O, with variable composition within this range, and often also incorporating partial substitution of Al for Si Calcium silicate hydrate C-A-H Phase more complex than C-S-H Calcium aluminate hydrate C-A-S-H This is even more complex than C-S-H and C-A-H Calcium aluminate silicate hydrate AFt C6AS3H32, sometimes with substitution of Fe for Al, and/or CO2− 3 for SO2− 4 Calcium trisulfoaluminate hydrate, or ettringite AFm C4ASH12, often with substitution of Fe for Al, and/or various other anions such as OH− or CO2− 3 for SO2− 4 Calcium monosulfoaluminate C3AH6 3CaO · Al2O3 · 6 H2O Hydrogarnet The hyphens in C-S-H indicate a calcium silicate hydrate phase of variable composition, while 'CSH' would indicate a calcium silicate phase, CaH2SiO4. ## Use in ceramics, glass, and oxide chemistry The cement chemist notation is not restricted to cement applications but is in fact a more general notation of oxide chemistry applicable to other domains than cement chemistry *sensu stricto*. For instance, in [ceramics](/source/Ceramic) applications, the [kaolinite](/source/Kaolinite) formula can also be written in terms of oxides, thus the corresponding formula for kaolinite, - Al2Si2O5(OH)4, is - Al2O3 · 2 SiO2 · 2 H2O or in CCN - AS2H2. ## Possible use of CCN in mineralogy Although not a very developed practice in mineralogy, some chemical reactions involving silicate and oxide in the melt or in hydrothermal systems, and silicate weathering processes could also be successfully described by applying the cement chemist notation to silicate mineralogy. An example could be the formal comparison of [belite hydration](/source/Belite#Hydration) and [forsterite](/source/Forsterite) [serpentinisation](/source/Serpentinite#Formation_of_serpentine_minerals) dealing both with the hydration of two structurally similar earth -alkaline silicates, Ca2SiO4 and Mg2SiO4, respectively. **Calcium system** - [belite hydration](/source/Belite#Hydration): Belite2 Ca2SiO4 + water4 H2O → C-S-H phase3 CaO · 2 SiO2 · 3 H2O + portlanditeCa(OH)2 Reaction 4a 2 C2S + 4 H → C3S2H3 + CH Reaction 4b **Magnesium system** - [forsterite](/source/Forsterite) [serpentinisation](/source/Serpentinite#Formation_of_serpentine_minerals): Forsterite2 Mg2SiO4 + water3 H2O → serpentine Mg3Si2O5(OH)4 + bruciteMg(OH)2 Reaction 4c 2 M2S + 3 H → M3S2H2 + MH Reaction 4d The ratio Ca/Si (C/S) and Mg/Si (M/S) decrease from 2 for the dicalcium and dimagnesium silicate reagents to 1.5 for the hydrated silicate products of the hydration reaction. In other term, the C-S-H or the serpentine are less rich in Ca and Mg respectively. This is why the reaction leads to the elimination of the excess of [portlandite](/source/Portlandite) (Ca(OH)2) and [brucite](/source/Brucite) (Mg(OH)2), respectively, out of the silicate system, giving rise to the crystallization of both hydroxides as separate phases. The rapid reaction of [belite](/source/Belite) hydration in the setting of [cement](/source/Cement) is formally "chemically analogue" to the slow natural hydration of [forsterite](/source/Forsterite) (the magnesium end-member of [olivine](/source/Olivine)) leading to the formation of [serpentine](/source/Serpentinite) and [brucite](/source/Brucite) in nature. However, the kinetic of hydration of poorly crystallized artificial belite is much swifter than the slow conversion/weathering of well crystallized Mg-[olivine](/source/Olivine) under natural conditions. This comparison suggests that mineralogists could probably also benefit from the concise formalism of the cement chemist notation in their works. ## See also - [Hydration of belite in cement](/source/Belite#Hydration) (analogous to forsterite hydration) - [Hydration reaction of forsterite (olivine) in serpentinisation](/source/Serpentinite#Formation_of_serpentine_minerals) ## References - Locher, Friedrich W. (2006). *Cement: Principles of production and use*. Düsseldorf, Germany: Verlag Bau + Technik GmbH. [ISBN](/source/ISBN_(identifier)) [3-7640-0420-7](https://en.wikipedia.org/wiki/Special:BookSources/3-7640-0420-7). - Mindess, S.; Young, J.F. (1981). *Concrete*. Englewood, NJ, USA: Prentice-Hall. [ISBN](/source/ISBN_(identifier)) [0-13-167106-5](https://en.wikipedia.org/wiki/Special:BookSources/0-13-167106-5). ## External links - [Cement and Concrete Glossary](https://web.archive.org/web/20050920222050/http://www.whd.co.uk/Understanding%20Cement/cementandconcret.html) --- Adapted from the Wikipedia article [Cement chemist notation](https://en.wikipedia.org/wiki/Cement_chemist_notation) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Cement_chemist_notation?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.