Everything about white cement

  Magic 5 percent, about the quality of cement

In the article "Signs of cement" mentioned that cements bearing the CEM (whether it is a cement type N or R) contain a number of components "outside clinker" in the range of 0-5%. It is usually due to the fact that in each cement are i.a.:

  • alkali (conversion to Na2O)
  • sulphates (conversion to SO3)
  • chlorides (converted to Cl`)
  • insoluble residue
  • others (eg. magnesium oxide - MgO

The limit values of the standards refer to an amount up to about 9% (some of them, eg. alkali no specific limit values), but their extreme values can strongly affect the quality of the cement, which means that their real and effective amounts are much lower.

Every seller and every cement producer has an obligation to share the results of physicochemical tests speaking about what is in the composition of the type of cement, which will allow the buyer to check the goods before buying. Currently, these results are typically available on merchant websites (often by reference), representatives of the manufacturer in the country or directly on the sites of manufacturers. Should be available at least three versions of such information:

  • the first contains the studies that are valid for a certain period of time (usually a year), made in the country of sale
  • the second contains a statement of what the producer actually sells; You can encounter concrete results of research data or range of information that these results concern min. 95% of the samples
  • third - the results of samples from a foreign country (if, for example. there is no representative of the manufacturer for a country in which any, the office is)

All three of these information should be coherent, consistent and, if not identical, at least very similar. Thorough check of these sources can tell how good (or not) the product is offered to us.

The premise and it's essential is that such a relatively large market like Germany, France or Poland no big manufacturer of white cement does not produce the unique and exceptional product - a maximum of adapting to the requirements of local law changes the descriptions on the bag, mark or set of information about sustainability. It is often associated with local standards and customs. This assumption means that the cement sold in a particular country (eg. 42.5 IN CEM or CEM 52.5 IR) should have a counterpart in the manufacturer posted on its website.

If you find any, that the cement is - there is no problem if the lack of it - can mean that really the product that is offered to us may contain something else, or fillers listed in the technical characteristics. It is very important that the additive may change some of the properties of cement in a situation where you add chemicals - whether we understand it as "traditional" or professional. This "traditional" is simply a different recipe passed time from generation to generation, for many years, fulfilling the same role as modern chemistry renowned manufacturers

For example - if the unmarked ingredient is limestone (specifically limestone ground - the notations L or LL), under the influence of various additives can turn into a variety of scale, that is what we know from kettles - yellowing grout or mortar. It is so embarrassing about it differently than "pure mortar" absorbs water, is resistant to the action of acid environment, which may result in damage to the grout or mortar due to rain.

Interestingly, the use of limestone as a "charge" to a concrete finally was approved only in the 80s and is in an amount of not more like a few percent to low strength concrete.

Another possibility - ashes, fulfilling the conditions of the norms for them assigned can vary enough in its composition (different manufacturer, specifically the different part of the "charge" of what is created), that chemistry can for that different physicochemical composition very react differently, giving extreme results. This is all the more likely if stronger measures are what we add, and you can find those whose limits are expressed in tenths of a percent added to the weight of the mortar or concrete (sometimes it does not exceed 0.3%).

Another equally important issue is to compare the data provided on the manufacturer's website, the data provided by the research center in the country (or its equivalent in the country's distributor), and the data published by local institutes. All these numbers and values should not differ significantly from each other.Subtle differences are normal - for a simple reason: cement is manufactured from natural ingredients - and thus slightly different from each other. These differences in the production process are mitigated, but not always possible to remove them until the end. Small fluctuations can be taken with some differences in survey methodology. What is different, however, the disparity in strength of cement 3 MPa (eg. in a one document 75 MPa, 72 MPa in another assuming that the cement is a class 52.5), and another differential of about 10 MPa (67 MPa manufacturer's specifications. data from local test 56 MPa, even assuming that the cement is a class 42.5). Such large differences as in the second case suggest that the cement is something wrong, or that the product is simply uneven,with large variations in quality

If you have any doubt as to the composition of the cement, we can always call the seller, a representative for the country or the manufacturer (depending on what you buy and how organized the sale in our country) to thoroughly explain any doubts. Granting accurate information on the composition of cement or on where it can be obtained is an iron responsibility of the person being called. If our conversation did not dispel doubts, it is better sometimes to pay extra these few euros and buy the brand that gives you more confidence during use, has a more stable composition and simply know what it is cement.

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