Talk:Cement

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CEMENT

THE PRODUCT are bhai ye sab galat hai Cement is a chemical compound existing of limestone or chalk, clay, sand and gypsum to form the final product we know as cement. Limestone or chalk, clay and sand are burned at a temperature of about 1400 degrees Celcius in a rotary kiln or oven to create a product called clinker. The clinker is milled together with about 5% gypsum in ball mills to a fine powder, the final product.

USAGES OF CEMENT Cement is used in various applications such as a substance to build brick houses (to bind the bricks together), in a mixture with sand and stone it is used as concrete for the foundation of a house or the walls of larges buildings or to build bridges or heavy construction work.

CONTRIBUTES TO THE ENVIRONMENT Cement manufacturers are striving to produce an environmental friendly product by incorporating power saving strategies and alternative fuel resources into the process.

Visit the British Cement Trade Association website www.bca.org.uk for more info

An environmental section is not fundamentality required for a user's understanding of the nature of cement. Although the data on carbon dioxide emissions is intriguing, it is not necessarily the truth and needed to demonstrate the uses of cement.


Note: regarding the info on main page; gypsum plaster and ordinary lime are NOT hydraulic cements as they do not form insoluble hydrates during curing; they will not set underwater; and if set and then placed underwater, will dissolve. Any decent basic source will reflect this e.g. Taylor, Cement Chemistry; Illston, Construction Materials; Neville, Concrete Technology etc etc.

Contents

[edit] Portland cement bias

This article with its recent changes is starting to concern me as it is developing a distinct bias towards Portland cement which already has an article of its own. Most of the recent additions, with regard to fuel, setting/hardening, environmental impact, are not about cement in general, and ignore other cements such as natural cements, calcium aluminate cements, magnesium oxychloride cements, phosphate cements, and others. Kpeyn 13:13, 24 August 2006 (UTC)

I've removed a bunch of Portland cement stuff recently. It's still missing information about other kinds of cements. Argyriou 19:31, 28 August 2006 (UTC)

In fairness, the term "cement" in common parlance almost always means a Portland-type product, and these products account for 95+% of world production. But I think details of manufacture etc need to be replaced with a refernce to the Portland article. Next job: to get the Portland article in shape.LinguisticDemographer 00:03, 28 September 2006 (UTC)

I think that Portland Cement should probably be folded into this article. I think that mention of other types of cement should be included on the periphery, with the main subject matter of the article being Portland Cement. This, given that the vast majority of cement produced in the world is portland cement. When people talk about "cement" in conversation it is overwhelmingly assumed that the person is referring to portland cement. -- Joetheguy 18:37, 13 November 2006 (UTC)

There is some justification for this; for example, the French article combines all cements under one title. But this may just be because Portland is a bit too English for the French. Furthermore, the European standards just treat Portland as one of many possible "common" cements. On the other hand, US standards still maintain, to the point of neurosis, a rigid distinction between Portland and "blended" cements. I said above that 95% of world cements are "Portland-type", but a large proportion of those are "blended". Given that a "branched" structure is what we currently have, and one can easily click a link to get to the Portland article, and because disputes of this kind are making badly-needed refinement of the articles difficult, I am proposing exactly the opposite course of action, as mentioned in "Rationalization" below. . . LinguisticDemographer 22:15, 15 November 2006 (UTC)

[edit] Modifications 28 Sept 06

I have put in a bunch of extra stuff which I hope remedies some of the existing problems. I have yet to learn how to drop the font size in the math symbols - perhaps someone can show me how.LinguisticDemographer 23:55, 27 September 2006 (UTC)

[edit] Expansion details

Does anyone have any suggestions for specific items that are missing from this article, or can the expansion tag at the top of this page be removed? -- Beland 15:35, 16 October 2006 (UTC)

Information on non-portland cements. Argyriou 15:57, 16 October 2006 (UTC)

[edit] Reactions

Can anyone tell me exactly what happens to the cement when it dries? All my textbook says is 'When water is added, a complex series of reactions occur which make it set'. Nonagonal Spider 06:30, 24 October 2006 (UTC)

The answer for Portland cement is explained fairly thoroughly. Argyriou 07:21, 24 October 2006 (UTC)

[edit] Rationalisation

There was a reversion (22:08 5 Nov 06) of a fairly sensible edit, which prompted me to have another look at the article as a whole. It's problematic because the term "cement" has a very wide scope of specialised use, although in normal parlance in most languages it means just one thing. The current structure discourages effective editing. There may be a standard wiki-approach to this problem, but it's a closed book to me so I offer the following re-arrangement suggestions for discussion.

  • change current disambiguation statement to read "For uses other than Construction Cements, see Cement (disambiguation)".
  • accordingly, remove "Geology" section, which disrupts the logical flow of the article.
  • organise the remaining article into main sections (1) hydraulic, (2) non-hydraulic (of which we currently have few examples)
  • In the hydraulic section, start with a definition of hydraulicity, which will absorb the current "Setting and Hardening" section.
  • Follow this with "History of Hydraulic Cements". Under this title, it is now sensible to mention early cements in time sequence, pointing out how hydraulicity was achieved in each case, and elaborate as knowledge allows.
  • Then follows "Modern Hydraulic Cements", which breaks out into categories as in current sections 4.1-4.3. As far as possible, refer discussion of "pure" Portland to the Portland article.

I'd also like to remove the reference to US usage of the term "Hydraulic cement" from the preamble, because reference to ASTM Specification C 1157 and terminology C 219 shows that US usage is in line with usage elsewhere. Currently it's very confusing.

The above will I think free-up the considerable expansion of the article that is still necessary. The above is fairly radical surgery, and I'd like to get a few nods of agreement before proceeding......LinguisticDemographer 21:04, 9 November 2006 (UTC)

Sounds good, though I'd make an article of the geology section rather than just deleting it. I'd also suggest adding Portland cement to the disambig page. Argyriou (talk) 23:09, 9 November 2006 (UTC)

I have placed a draft of the article amended as proposed above in User:LinguisticDemographer/Draft, resisting the urge to be bold and put it straight in, since tempers seem to be a bit frayed at the moment. Hopefully, it covers (with citation) the current war over "what the Romans put in their concrete". I took out most of the reference to fuels, since it seems to me that specialised Portland-based processes do not belong in this article, and they are indeed covered in Portland cement and cement kiln, though perhaps not in a way satisfactory to all opinions. Anyway, I'd like some feedback. . .LinguisticDemographer 19:46, 15 November 2006 (UTC)

There being no comment, and no recent edits compromising the suggested text, I have implemented the above LinguisticDemographer 12:11, 9 December 2006 (UTC)

[edit] Trade

As threatened in the portland article a month ago, I have moved the section on trade from there to here, because it refers to all cements and not specifically Portland. . . .LinguisticDemographer 15:18, 27 May 2007 (UTC)

[edit] cement

why is it not adviceable to keep cement expossed to air? —Preceding unsigned comment added by 81.199.17.19 (talk) 09:30, 4 March 2008 (UTC)