Everything about white cement

  The new Polish white cement (based on spanish clinker)

In a free market, anyone can operate and offer their wares - from great, whose name is unknown, the little known within the community or more. The same freedom also means the possibility of introducing a new product, which is intended to compete with those that already exist on the market.

Doubts arise at a time when trying to describe something in a way that is inconsistent with the facts or with certain rules in force in the market. It first means that the given number or warehouses non-reflection, in fact, the latter is usually the most common violation of the unwritten codes, polluting give such and no other class or group to which belongs the product.

The rules take these mostly from the statistics. In theory, there are statistical concepts such as average score and standard deviation, standard distribution, and the results reported with 95% confidence.

The average score - is simply the average value reached by the research the commodity or product. These studies may relate to the composition, physico-chemical parameters and others - everything that is measurable.

Standard deviation - is a measure showing how the results are deviated from the average. The closer the focused, the better.

Normal distribution - this is a classic chart showing how samples and what their number reach individual extreme values. Interestingly, all studies involving certain repetitive processes based on the same or almost the same material (input) is the same.

Confidence of 95% or 95% confidence interval, more statistics of the assumptions 95.5% - comprises a sample twice the value of the standard deviation; it tells us that in the given interval is more than 95% of all test results including sample data, the material.

With this you can draw three conclusions - each logical, each located confirmed in practice:

  • if there is a brand of cement (class) 52.5 - it means so much that the weakest sample, which was tested must meet the requirements for this standard. Not average, not the 95% confidence, but each. Interestingly some manufacturers next research disposable feeding eg. That in a study of cement reached a strength of 73 MPa after 28 days indicates that the strength reaches between 68 and 76 MPa. That is, the worst result ever "left" to 68 MPa, and the best - 76 MPa, and all the test samples in this interval and the next fit should fit.
  • these results also indicate that at these parameters - the average is 72 MPa and the value of each sample fluctuates within + -4 MPa, that he was actually + -5%, or even slightly more. This is very important information, telling enough that really any value specified by the manufacturer (sample should be as random) in the course of production can vary for these 5%, and even a little more. This is a simple reason - the basis for the production of cement materials are of natural origin, which makes the "initial" the composition of the mixture may have the right to gently vary, and thus also affect the final results to the extent slightly greater than if each batch was perfectly the same. By the way, this is a statistic that makes any producer of any goods packed in any package shall contain information: the weight of X units of + -5%.
  • reading the exact results given class of cement can be seen that the manufacturers are trying to be honest, especially producing cements higher classes (42.5 and 52.5) ??and the margin performance of the individual is truly worthy of respect, sometimes reaching supply approx. 12 MPa class 42.5 - which means supply up to 25%. However, taking into account the above-mentioned reservations both as to the ingredients, and statistical assumptions, it is clear and obvious.

Relatively recently appeared on the market a new producer of white cement. In fact, this is not a full production, but only partial, but the fact that it is a new product - you can not hide. Reading the information on its website, the person sitting in the so-called. industry amazes from the very beginning, the biggest surprise falls after news that cement class 52.5 is identical results as cement grade 42.5. This means that something can not play.

The most important given saying to what class he belongs strength is the strength normalized after 28 days. The manufacturer says that once it reaches 54.5 MPa and 56 MPa time as the standard 52.5 means that the "reserve" strength reaches barely 2-3.5 MPa, given the results of the margin of error is only approx. 2 , 5%, which is actually or material is perfectly equal, or that the margin is very economical. At 5% margin of error values, what would these samples (each of them can taken from any batch of the product at any time) achieved amount to between approx. 52.5 and 59 MPa. Such results for many producers of gray cement would mean that this would cement the brand of the lower class, which is 42.5.

The following will be included data provided by manufacturers of various types (classes) of cement available on the websites

Manufacturer A-b C-b-G C-sz-G C-sz-C N-sz L-M1s L-K L-M2s CWsz CW2sz
Beginning setting time [min] 122 120 144 174 210 202 169 190 165 165
End of setting time [min] 161 180 235 271 257 224 235 205 210
Strange after 2 days [MPa] 43 35,9 28,3 29,7 32,5 29,1 28,05 36,8 26,2 36,2
Strength after 28 days [MPa] 74 54,5 51,7 56,1 57 56,5 56,64 61,2 60,7 70,4
Class 52,5 52,5 42,5 42,5 42,5 42,5 42,5 52,5 42,5 52,5
Blaine specific surface
3870 4189 3767 3983 3575 3517* 3425 4688 3591 4482
Losses of ignition [%] 0,5 1,32 2,35 2,42 2,28 3,6 2,87 3,7 2,61 1,91
Insoluble residue [%] 0,1 0,29 0,62 1,27 0,58 0,6 0,47 0,7 0,37 0,42
Sulphur SO3 [%] 2,2 2,69 2,95 3,06 2,79 3,06 3,31 3,42 2,73 2,9
Chloride Cl [%] 0,02 0,055 0,061 0,007 0,064 0,03 0,056 0,028 0,022 0,022
Alkali [%] 0,2 0,8 0,63 0,79 0,47 0,46


  • standard for LA cements in Poland: to 0.6%
  • strength normalized for cement class 42.5 after 28 days is between 42.5 and 62.5 MPa
  • strength normalized for cement class 52.5 after 28 days to strength over 52.5 MPa

Legend signs manufacturers:

  • A-b - a leading manufacturer of white cement class 52.5
  • C-b-G - the producer of a new brand of white cement class 52.5
  • C-sz-G - the same producer of gray cement class 42.5 produced in the same place as white
  • C-sz-C - the same producer, another cement plant, gray cement class 42.5
  • N-sz - one of the producers of gray cement class 42.5
  • L-M1s - producer of gray cement, one of the cement plant, cement gray 42.5. *Now Blaine specific surface is about 3200.
  • L-K - the same manufacturer, another cement plant, gray cement class 42.5
  • L-M2s - the same manufacturer, the first cement plant, cement class 52.5
  • CWsz - another cement, gray cement class 42.5
  • CW2sz - the same cementing, cement gray class 52.5

One more little explanation - because of the requirements posed by the Polish standard for different types of cements (cements class 32.5 strength is at a level between 32.5 and 52.5 MPa after 28 days), manufacturers are trying to make their cements They meet all the standards by a wide margin. Looking at the cement class 52.5 can justifiably say that for them the minimum "reserve" is the standard limit of approx. 10 MPa, so the strength min. 60 MPa after 28 days the average value of the tests. That supply is also a guarantee that every sample of a surplus will fulfill the strength contained in the standards

Analyzing a little more closely, you can easily notice that the new white cement, in theory class 52.5, is absolutely the weakest of cement this class, and nothing stands out in terms of performance of the cement class 42.5, while even among them this is a sensational result, giving him one of the last places in the rankings after a fairly large.

Comparing the data with the results of that cement, which is a leading producer of white cement can be seen how much this is far-fetched. Producer marked A-b - the result of approx. 54-56 MPa reached after about 7 days, not 28 ...

All this means that the really new cement class 52.5 presented by the manufacturer marked with the letter C - it really is a decent cement class 42.5 but nothing more, because you can easily find cements its class to achieve a better performance from him; Interestingly this result is achieved even one of the cement plants of the same manufacturer.

In order not to be completely groundless, the following will also be presented the results of cements Type II (usually marked BV), the most popular class 32.5. The results also will meet with significant exceed the requirements for this class of cement. The rules are similar to those included in the table earlier.

Beginning setting time [min] 215 220 270 204 270 206 207 212 263 245
End of setting time [min] 280 280 376 258 359 310
Strength after 2 days [MPa] 18,4 18 18,8 17,3 19,7 23 19,1 18,5 16,2 16,1
Strength after 28 days [MPa] 41,2 44 41,6 38,8* 47,9 49,6 50,1** 49,8 52,2 47,1
Class 32,5 32,5 32,5 32,5 32,5 32,5 32,5 32,5 32,5 32,5
Blaine specific surface
4373 5700 3525 4103 3300 3964
Losses of ignition [%] 2,95 3,21 3,38
Insoluble residue [%] 24,69 1,14 11,33
Sulphur SO3 [%] 2,86 2,7 2,4 2,5 2,7 3,26 3,15 2,1 2,5 2,79
Chloride Cl [%] 0,076 0,07 0,054 0,036 0,071 0,077 0,064 0,073 0,07 0,02
Alkali [%] 1,28 1,15 1,16
  • CCIIB - Cement production of the same manufacturer as the new white cement, type II BV, plant C
  • CBIIB - Cement production of the same manufacturer as before, with no signs of the cement plant, type II B-M
  • CNIIB - Manufacturer of gray cement, class 32.5 type II BV
  • LKIIB - Manufacturer of gray cement one of the cement, class 32.5 type II BM (* elsewhere in the average value given as 42.78 MPa)
  • The same producer as the previous one, another cement, class 32.5 type II BV
  • COIR - Another domestic producer of cement, cement class 32.5 type IR
  • COIIB - COIIB - The manufacturer is the same as above, cement class 32.5 type II BV (** elsewhere in value for the 28 days is 48 MPa)
  • GGIIB - Manufacturer of cement class 32.5 type II BS
  • GCIIB - The same producer is earlier, the cement grade 32.5, the type II BS
  • WCIIB - WCIIB - Manufacturer of cement class 32.5 type II BM

Reading through the data presented above, it can be observed exactly the same regularity as in the case of cement higher class, with the only difference that in this case the strength comparable with cements exceeds the norm by almost 1/3, sometimes even more. In absolute numbers, this means that every manufacturer tries to make the average scores were not lower than 40 MPa (standard speaks of min. 32.5 MPa), and some manufacturers receive the results of strength tests within 50 MPa.

Such high results give assurance that every, literally every sample meets the minimum requirements of the standard. Interestingly, many of them do not declare these cements as class 42.5, though in truth they could do so without much problem.

In some cases manufacturers in addition to studies on specific samples of the day or month publish up the average results from a long period of time. In one of the cases deviation from this mean was approx. 4 MPa, the strength is achieved almost 10% of the declared value of the deviation of the mean. In the second case the deviation was lower and amounted to "only" approx. 4.5%, this time for a change up.

That is why the response of the producers, despite such high "excess material" will declare cement as a class a little less than they could do it. In absolute numbers, in spite of different strength classes it looks surprisingly similar - the surplus is min. 10 MPa for both cement type 32.5 and 42.5, as well as those best 52.5. Sometimes reaches much higher values.

With this rule breaks only new white cement placed on the market, the surplus is essentially the minimum, both in absolute numbers and as a percentage.

In Poland you can buy cement class 52.5 in several cement plants and warehouses and representative offices of global corporations. If the previous considerations are correct, it is also every time testing the cement (not penetrating or white, or gray) should indicate the average score in the range of 60 MPa, with the result that should be close to at least approx. 62 MPa.

To understand further consideration, you still have time to go back to the statistics. Knowing the range of results (which are declared by the manufacturer) that reaches the commodity can be quite a close approximation to calculate the standard deviation from the mean. With four times the standard deviation from the average less than one in 100 thousand. samples, do not meet standards. If each time a sample of the goods is a bag, a manufacturer wrong time to 2.5 million tonnes, and if we take into account the five-fold deviation from the mean - producer wrong (with similar assumptions as above) less than once every 25 million tons of cement; sixfold deviation from the average - less than once every 2.5 billion tons ... Assuming that the deviation from the average result is a maximum of + -5 MPa can be assumed that the standard deviation is between 1.25 and 1.5 MPa.

In the table below in a similar way as before will be described properties of cement grade 52.5.

Beginning setting time [min] 122 120 165 210 203 220 155 164 205 248
End of setting time [min] 161 210 265 265 280 249
Strength after 2 days [MPa] 43 35,9 36,2 34,2 36,8 29,4 32,6 34,9 34 24,1
Strength after 28 days [MPa] 72* 54,5** 70,4' 63,8' 61,2'' 60,1'' 56,9'' 61,8'' 66,4# 58,1#
Class 52,5 52,5 52,5 52,5 52,5 52,5 52,5 52,5 52,5 52,5
Blaine specific surface
3870 4189 4482 4398 4688 3386 5362
Losses of ignition [%] 0,5 1,32 1,91 1,72 3,7 0,23 3,15 0,85 0,82
Insoluble residue 0,1 0,29 0,42 0,46 0,7 0,58 0,6 0,9 0,51 0,38
Suphur SO3 [%] 2,2 2,69 2,9 2,72 3,42 2,84 3,06 2,4 3,36 2,75
Chloride Cl [%] 0,02 0,055 0,022 0,021 0,028 0,005 0,044 0,07 0,012 0,008
Alkali [%] 0,2 0,46 0,29 0,79 0,46 0,75 0,5 0,52
  • A-b - a leading producer of white cement class 52.5 (* vendor in the overall information will provide a range of results that can be achieved within the limits of 66-76 MPa, as the average score given is 72 MPa, and the result of this particular test is 74 MPa, the other - 71 MPa , a difference of + -1.5 MPa (not shown tenths))
  • CbG - producer of a new brand of white cement class 52.5 (** manufacturer shall also another result oscillating around 56.1
  • WRNa - one of the cement, gray cement class 52.5 type of RNA, one of the available offer ( 'the producer does not provide concrete results, just average)
  • WNHs - the same cement as above, the cement class 52.5 N-type HSR, the second are on offer in this class ( 'manufacturer does not provide concrete results, just average)
  • LMIR - another cement producer, one of the cement class 52.5 type IR ( 'manufacturer gives the result for specific test - strength is 61.5, which is again a deviation in the range of + -1 MPa)
  • LKNh - the same manufacturer, one of the cement, class 52.5, N type HSR, ( '' the manufacturer gives the specific research strength - 59.7, again the deviation from the average value in the range of + -1 MPa)
  • LMII - the same manufacturer, one of the cement, class 52.5 type II A-M ( 'manufacturer gives the result of a specific investigation - the result is 57 MPa in terms of accuracy given average - commentary unnecessary)
  • HGIR - another producer of cement, class 52.5, the type of IR ( '' the manufacturer gives only average values ??of tests)
  • CRIR - another cement producer, one of the cement, class 52.5, type the IR NA (# manufacturer claims a specific test result - 65.7 MPa; again, the measurement error in the range 1 MPa)
  • CRIN - the same manufacturer, one of the cement, class 52.5 type IN HSR (# manufacturer gives a concrete result of the test, its score of 56.2, a difference compared to other types of cements when this value is quite high, reaching for some . 2 MPa, while in other cases generally does not exceed 1.5 MPa)

Considering what was previously indicated should be stated that:

  • new white cement is one of the weakest in this class, and depending on the results presented on the manufacturer the worst, or one of the two worst
  • considering that it is a cement-type IR - that is, without additives, without any technological changes etc. to eliminate alkali must be recognized that in this class, the result is the weakest
  • the reported results have the greatest possible range compared to other manufacturers, especially considering the strength achieved by them
  • in principle, apart from the three types of cement, two of which are mentioned as IR type - that is, without additives, cement producers have all the average test results above 60 MPa, which is consistent with observations in classes worse, and thus 32.5 and 42 5

Assessing posted above information and analysis on the strength of a clear answer about the new white cement class 52.5 and of which class more fit its parameters, especially considering the fact that it is a cement-type IR or without additives, which means, so really its strength should be much higher to the average results of strength after 28 days were above 60 MPa.

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