Associate Professor M. I. MESHCHERYAKOV.

PORTLAND CEMENTS

IN THE CONSTRUCTION PRACTICE OF WESTERN SIBERIA

Tomsk, 1929.

Associate Professor M. I. Meshcheryakov.

PORTLAND CEMENTS

in the construction practice of Western Siberia.

(From the materials of the Laboratory of Technology of Mineral Substances and Building Materials of the Siberian (Tomsk) Technological Institute for 1913–1927.)

Introductory note. The construction practice of the pre-revolutionary period of certain departments, chiefly the Ministry of Ways of Communication and the military department, made it a rule to subject, if not every shipment, then a significant percentage of shipments of Portland cement to control laboratory testing before allowing it to be used, regardless of the fact that the delivery of the cement had been tested in the factory laboratory that conducted production control.

The purpose of testing was to ascertain that the Portland cement of a given shipment satisfied the developed and accepted “Norms,” a certain obligatory minimum of requirements embodied in the officially approved act (standard): “Technical Conditions for the Acceptance of Portland Cements,” assuming that cement which had withstood the tests according to the “Norms” would, in further service in construction, prove to be of good quality. The “Norms” provided, as does the currently valid standard of 1927 for the USSR, not only numerical values of the minima, but also the procedures and methodology for carrying out tests, for the sake of the necessary uniformity and comparability of the data obtained. Therefore, the experimental material of control laboratories may be used as a basis for scientific conclusions and generalizations.

With the production of P.-cement, which in Russia in 1915 reached 15 million barrels at 58 plants, provided that each tested shipment included 3,000 barrels (the maximum number of barrels in a tested shipment according to the “Norms” of 1911–1913), and that only 10% of the cement produced by the plants was tested in the laboratories of state institutions (higher educational institutions or special testing stations), to which the tests were entrusted,* over a number of years an enormous body of experimental material must have accumulated in these laboratories, recording the properties of the P.-cements released onto the market by the plants.

Each of these tests individually has a definite and decisive significance, first of all, for the shipment being tested; and in this, perhaps, lies one of the reasons why experimental material on laboratory tests of P.-cements has never been published in detail, even in publications specially devoted to service of the cement industry: the journal Cement from 1900 to 1915, and Portland Cement in 1916–1918.

In scientific publications concerning P.-cement, one may most often encounter only summary annual data of the most general character, undoubtedly based on the experimental material obtained in tests.

*) According to the standard contract, the supplier of cement and the recipient agreed upon some state laboratory, which was to perform control tests of the cement and whose conclusions were considered non-appealable.

Detailed experimental laboratory material was published in an insignificant fraction of a percent only in advertising publications*) of factories, where usually no more than a dozen tables of tests of Portland cement from the factory being advertised were given, together with an official certificate on the qualities of the product it issued; moreover, the data were compiled without system and often refer to a whole series of years.

The experimental material collected by control laboratories on the testing of Portland cements is, of course, of greater value than illustrations for advertising.

By bringing together the experimental material of all laboratories that have at any time tested the cement of each individual plant; by compiling summaries by districts served by a certain group of plants; and, finally, by making a comparison for all plants, we would obtain a complete picture of the state of the Portland-cement industry in the state, both in the past and at present. In these summaries and comparisons, the qualities of the product released to the market would be clarified with certainty; the position of a plant among others in the district and in the entire country with respect to product quality would be made evident; and, to a certain extent, the character of the plant’s work—inasmuch as it can be judged from the properties of the product released to the market—would become clear; fluctuations in production and the shortcomings encountered, which are smoothed over in the final figures, would be noted.

Finally, from detailed test data it appears possible to conclude to what extent tests according to standard norms (“technical acceptance conditions”) make it possible to detect and confidently establish the qualities of the material being tested for its future service in construction.

What follows is the author’s attempt to analyze, in accordance with the above, the experimental laboratory material on the testing of Portland cements at his disposal.

The Laboratory of the Technology of Mineral Substances and Building Materials of the Siberian (Tomsk) Technological Institute, over a number of years, tested samples of Portland cement from deliveries for the construction needs of almost all railway lines of Western Siberia: the Siberian, Omsk, Altai, Achinsk-Minusinsk, Kulunda, and Kolchugino lines, as well as on assignments from public organizations.

Portland cement came from various plants.

To meet the needs of construction in Western Siberia for hydraulic binding materials, since 1895 there had existed here one cement plant—the Kamyshet plant—which released to the market Portland cement in an amount not exceeding 50,000 barrels per year. The output of this plant did not cover the construction demand for Portland cement; the shortage was made up by imported cement from plants of European Russia, chiefly from the Volga region (the Glukhoozersky plant, Zeifert’s plant near the town of Volsk). In 1913 another Siberian, newly built plant, the Yashkino plant (Yashkino station, Tomsk Railway), began to release its Portland cement to the market. Designed at first for an output of 60,000 barrels of Portland cement per year, this plant toge—

*) Of the Yashkino plant in Siberia; of the Nevyansk plant in the Urals; of the Maltsov plant in Russia.

...with the Kamyshensk plant likewise could not cover the needs of Siberian construction for Portland cement; therefore, even in the years when both Siberian plants were operating, the Portland cement required for construction continued to be taken, chiefly as before, from the above-mentioned Volga plants. In 1914, for the work of building the Achinsk–Minusinsk Railway, there was even a supply of Portland cement from Denmark (the Aalborg works), arriving at the site of the works by the northern sea route. From 1914 onward Portland cement from two Ural plants appears on the Siberian market: the Katav-Ivanovsk and the Nevyansk plants. These plants, situated closer to the main sections of the Siberian lines, later replaced, with their product, the Portland cements of the Volga plants.

The experimental material collected by the laboratory over 15 years (1913–1927*) inclusive, during tests of batches from deliveries of Portland cement from the plants named above, will constitute the subject of further consideration.

The numerical data obtained in the tests are reproduced in the form of composite diagrams Nos. I–II–III, since in a graphical representation the fluctuations in the readings of individual samples of Portland cements stand out more clearly than in a table.

From diagram No. I, reproducing the detailed experimental material of the tests, it is evident that the greatest number of data, both by number of years (14) and by number of individual samples (161), relates to the Siberian Yashkinsk cement plant. The samples relating to one year of testing are separated in diagram I by a vertical solid line. The number of samples from year to year is uneven; it varies from 1 (1920–1921–1924) to 32 (1914). In the years when a considerable number of samples entered the laboratory (13, 32, 15, 17, 23, 17, and 18 samples), one may consider, taking into account the total output of the plant and the number of barrels in the tested batches, that no less than 15–20% of the entire output of the Yashkinsk plant passed through control tests. It should also be noted that the greatest number of official tests of cement from the Yashkinsk plant, if not all, were carried out by the laboratory of the Siberian Technological Institute. Thus, the test records for Portland cement from the Yashkinsk plant, collected by the STI laboratory, are for the Yashkinsk plant of Sibgoscement the most numerous official documents recording data on its cement, and the principal material for the corresponding conclusions on the qualities of the product and for characterizing the work of the Yashkinsk plant itself.

The data relating to other plants that supplied Siberian construction during the years under review are comparatively few; they are sometimes limited to a single year or to a small number of samples in one year.

Thus, for the Glukhoozersk plant (the city of Volsk), in 1913, 17 samples were tested; in 1914, 6 samples, out of a total number of barrels of 75,000.

For cement from the Nevyansk plant: in 1914, 2 samples out of 1,881 barrels; in 1915, 11 samples out of 25,000 barrels; in 1916, 1 sample—3,000 barrels; in 1918, 5 samples out of 2,800 barrels.

For Danish cement (Aalborg, Denmark): 1914—7 samples out of 16,000 barrels.

For cement from Steffen’s plant (foreign): 1914—2 samples out of 2,000 barrels.

* In 1917 the laboratory did not test cement samples.

For the cement of the Katav-Ivanovsk plant: 1914—1 sample from 500 barrels; 1915—1 sample from 1,000 barrels; 1918—2 samples from 2,000 barrels.

For the cement of the Kamyshletsk plant: 1913—3 samples from 2,000 barrels.

The cements of the last five plants (apart from the Siberian Kamyshletsk) are, for the most part, used in construction in other districts, where the majority of control laboratory tests are also carried out. Detailed data from these tests have not yet been published by any laboratory. Therefore, in the subsequent summaries and comparisons one must use only the available and, undoubtedly, insufficient experimental material, relating to a small percentage of the product from the plant’s annual output. Thus, with respect to the Glukhoozersk plant, approximately 4–5% of its annual output was tested; for the Danish plant—1%. However, even this scant experimental material cannot be considered devoid of all significance. With the plant’s work adjusted, and with established production methods depending on the raw material and equipment, even a small series of samples is capable of revealing the characteristic qualities of the plant’s product.

With respect to foreign cements, it should be borne in mind that they endured the contingencies of sea and land transport. The data from their tests indicate the quality of the cement that arrived for the works, but it is difficult to say what quality of cement was released from the plant.

In this capacity, a small and incomplete experimental material relating to cement plants located outside Siberia is accepted for consideration below.

In the appended Diagram I, the sample data are arranged chronologically according to the time of receipt and performance of the tests, separately for each plant.

In the annual summaries (Diagram II), there are given: 1) comparisons of the qualities of cements from one and the same plant over a number of years, and 2) comparisons of the annual averages of one year for the cements of several plants, as a characterization of the quality of materials used by construction in a single building season.

Diagram III gives a comparison of graphs illustrating the increase in strength of cement paste and sand-cement mortars during the first 28 days after gauging. The data are annual averages.

The numerical values of the minima of the “Norms” of the technical conditions for acceptance of Portland cements (“Norms” of 1911–1913) are shown in Diagram I by a horizontal line. The scale of the quantitative values of the individual indicators is indicated by the numbers on the first ordinate of the grid.

In a general review of the test results of Portland cements compiled in Diagram I, it is easy to observe that, for the overwhelming majority of samples, the “norms” of the technical conditions of 1911–1913 are not only satisfied, but the qualities of the tested product exceed the “norms” by 50–80%, and in some cases even more.

There were 17 rejected batches among the tested cements during the years under review. Namely: from the Yashkinsk plant, 10 out of 161 samples; from the Nevyansk plant, 6 out of 19; and from the Kamyshletsk plant, 1 out of 3 samples.

A cursory review of the diagrams makes it immediately apparent that, so to speak, there are few calm lines among them. These lines relate chiefly to those properties of cement that have small limits of fluctuation, precisely fixed by the standard “norms.”

Thus, for the normal amount of water when gauging cement-sand specimens, the standards indicate fluctuations of 2% (8–10%). The corresponding broken line of graph No. 12 has comparatively insignificant deviations of readings from specimen to specimen.

The limits of fluctuation for the normal amount of water when gauging a pure cement paste, permitted by the “standards” of 1911–1913, are 8% (from 22% to 30% by weight). The broken line of graph No. 11, reproducing the readings of the specimens, has sections of stable readings for a considerable number of specimens. The fluctuations in the data of the Yashkino plant do not exceed 3%; the same is true for the Glukhozersk plant. The corresponding readings of the Nevyansk plant break up into 2 sections: the first—below 25%—1914 and 9 specimens of 1915; the second—above 25%: 5 specimens of 1915 and 3 specimens of 1918, with a difference of 5.5% at the maximum.

Among the calm lines is curve 5-a, characterizing the residue on the 900-mesh sieve, openings/cm². The permissible limits of fluctuation here are 10%. The comparatively even character of the broken graph is disturbed, although within permissible limits, by significant deviations from the mean values of several specimens of Nevyansk cement and one specimen of the Yashkino plant: fineness of grinding from 4 to 6.55%, which is somewhat exceptional.

The second curve of the “fineness of grinding” of P.-cement, No. 5-6—“passed through a 4900-mesh sieve, openings/cm²,” illustrating the content in P.-cement of the most finely ground and most active fraction—according to the “standards” has fluctuation limits of 50% (50–100%). In practice, these permissible limits are reduced by production practice itself: no plant allows the fineness of grinding of cement to approach 50% in its fine fraction, nor does it bring it to a fineness of 100%. Many of its techno-constructional properties are connected with the grinding of P.-cement, and in order to release onto the market a product of satisfactory qualities, the grinding must be organized so that the finished cement, during testing, gives indications of its properties without sharp jumps and as far removed as possible from the minimums of the standard “norms.” In the diagrams there are only 2 specimens with grinding below 70% and 3 specimens giving 90% in the fine fraction. These limits of fluctuation of grinding in the fine fraction of cement, 70–90%, established by the practice of the plants, are almost the rule for Russian cements in the past. In the all-Union standard of 1927 it would already have been possible, without danger of hampering the production of P.-cement plants, to establish a new minimum: 70% for the fine fraction of grinding, instead of 50% according to the norms of 1911–1913.

The curve under consideration, No. 5-6, already shows few stable sections. Deviations are most often associated with a new delivery, in which individual specimens give comparatively close readings. The most restless broken line is given by Nevyansk P.-cement, with fluctuations up to 21.18% (90.2–69.08).

The broken line of the specific gravity of P.-cements, No. 10, the limiting values of which according to the standards are 3.05–3.2, for the Yashkino plant gives a picture of a smooth transition from rejected values of specific gravity (below 3.05) to comparatively stable readings over a number of years. This means that the plant, working with the same raw material, corrected its technique.

The specific gravity of the cement of the Glukhozersk plant fluctuates within very narrow limits: 3.07–3.10.

The specific-gravity readings are smooth for specimens of foreign cements (Danish, Stephenson), Katav-Ivanovsk, and Kamyshetsk. Cement

The Nevyansk plant disrupts the generally uniform picture: the readings of the 1915 tests are higher than those of 1914; they decline toward the end of 1915. The same decline is also observed in 1916, and, finally, all the tests (5) of 1918 give values of specific gravity below the standards (3.00–3.02), despite the fact that the samples belong to different shipments and to different dates of manufacture of Portland cement by the plant.

The broken line No. 6 of the diagram illustrates fluctuations in the bulk density of samples of Portland cement in the loose state, determined according to the methods prescribed by the “technical specifications for the acceptance of Portland cement.” The “standards” do not indicate any limits for fluctuations of this property of Portland cement. The cements actually tested gave absolute values of bulk density (of one liter) of loosely poured cement within the range from 982 g to 1300 g (deviations of 33%). The graph of the values under consideration is of interest when compared with the data on specific gravity, No. 10, and fineness of grinding, No. 5–6, for the same samples. One might expect that specific gravity and bulk density, as quantities relating to a single property of cement, would give similar sequences of deviations in meaning from one sample to another; in reality, however, it turns out that the theoretically assumed functional dependence between specific gravity and bulk density is completely obscured by the influence of grinding. The sequence of deviations of the broken line of bulk density No. 6 is most correctly found behind the curve of fineness of grinding No. 5–6, “passed through a sieve of 4900 openings/cm²,” only in the reverse order: with fine grinding the bulk density of cement is smaller, with coarse grinding it is the opposite. This correspondence is especially sharply observed at the maximum and minimum values of the grinding curve for the samples of the Yashkino plant and almost the entire curve of the Nevyansk plant. The observation described may have the following significance for construction practice: when Portland cement of fine grinding is measured by volume, a smaller weight is taken than of coarsely ground cement, but the quantity of the fine active part, calculated as a percentage of the weight, may turn out to be the same in both portions; when measured by weight, finely ground cement will give more active elements per unit of weight than coarsely ground cement. It remains to note that the changes in broken line No. 6 very consistently follow the deviations of graph No. 11—“the normal quantity of water for gauging neat Portland cement.”

Initial set of Portland cement, curve No. 8—the moment of thickening of the cement paste, noted by definite signs—has, according to the “standards” of 1911–1913, one limit: not earlier than 20 minutes from the beginning of gauging. Cements whose initial set occurs later than 20 minutes belong to the category of slow-setting cements and are the most commonly used in construction practice. Quick-setting cements have a special purpose and may be supplied upon special request. The phenomenon of rapid setting in cement for ordinary construction work presents a great inconvenience and removes such cement from the category of normal ones.

Curve No. 8 shows how successfully this requirement of practice was fulfilled in the Portland cements tested. The readings of cement samples fluctuate around a certain average value: 1 hour 10 minutes; the minimum is 40 minutes, the maximum is 2 hours 25 minutes, rarely exceeding 2 hours—and only a few samples from the Yashkino plant give short setting times—less than 2 minutes; these are quick-setting cements.

The setting time (end) of cement is the degree of hardening of cement, conditionally determined by certain signs: when a blunt ...

the needle of an instrument with a load of 300 g does not sink into the mass of cement, but leaves only a trace on the surface of the mass. The period of time during which cement of normal properties reaches the indicated degree of hardening, according to the “standards,” must vary from 1 hour to 12. According to graph No. 7, the amplitude of the divergence of the readings is about 8 hours: min. 2 h. 40 m.; max. 10 h. 30 m. Coincidences in the deviations in graphs No. 7 and No. 8, which essentially illustrate one and the same process of setting, but at different times, can indeed be observed; yet, in view of the presence of a considerable number of inconsistent deviations, it is more probable to assume that there is no direct proportionality between the beginning and the end of setting in the duration of these processes. Likewise, a weak analogy is observed between curve No. 7 under consideration and No. 6—the volumetric weight of the cement and, correspondingly, the fineness of grinding—5–6.

Judging by the changes in the curves of diagram I, not one of the properties of cement setting represented in the graphs stands in a functional dependence. A functional dependence of the rate of setting of cement on its chemical composition and degree of burning cannot be demonstrated, since in testing cement, according to the “technical conditions of acceptance,” analysis of the composition of the cement may be carried out, but usually is not performed. The degree of burning is not at all included among the tasks of control laboratory investigations.

The graphs of diagram I: 1-a, б; 2-a, б; 3 and 4 reproduce data obtained in tests of Portland cements for tensile strength (1-a, б for specimens of pure cement; 2-a, б—for cement-sand specimens), for compression (crushing)—graph No. 3, and the numerical value of the ratio of compression readings (cubes) to tensile strength for cement-sand specimens of 28-day age (graph 4). Among these graphs there are no “quiet” sections: they all have the appearance of broken curves with sharply differing readings of successive tests. Here one may speak only of more or less close readings of one delivery or one period of manufacture of Portland cement. In the course of the broken lines only a general consistency is noticeable, often disturbed by readings of the opposite sense: by a fall instead of a rise, i.e., instead of the expected increase in the strength of the cement tested, a decrease of it is observed (samples of Yashkino cement from 1914 and 1916: graph 1-a, б). All the readings of graphs 1-aб, 2-aб, and 3 are above the “standards”; however, some are very close to the limiting minimum. In graph “4” there are rejection sections (Yashkino cement, samples of 1913). A detailed analysis of these graphs will be given below.

An important property of Portland cement—constancy of volume—is not expressed by a number, which is why in a special column No. 9 marks “—” are made for cements that did not withstand this test.

Rejected batches are marked in a separate line with the sign “—” minus.

The notes of a cursory review of diagram I are: 1) the enormous majority of samples (92.22%) give readings exceeding the established minima of the “standards”; 2) certain particular readings below the minimum of the “standards”*) were found in 7.78% of the samples of the tested cements; 3) smoothness in the course of changes in very important properties of the factory product—tensile strength, compressive strength, etc.—is absent; these notes of a general character lead to the conclusion that, evidently, the pre—

*) A batch is rejected even for a single reading obtained in tests below that indicated in the “standards,” all other readings being favorable.

...the next test or delivery of cement from a given plant does not give an absolutely reliable guarantee that the one following it will have analogous or very similar qualities, especially with respect to such properties as compressive strength, specific gravity, and constancy of volume. Deviations in the results of one test from another are often considerable, and in individual cases the difference in the direction of a reduction of one result from the neighboring one exceeds that minimum excess over the “norms” which can be found in the test results for cement from a given plant. This is well illustrated by the comparison in Tables No. 1 and No. 2 below.

Table No. 1.

Tests of neat cement for tensile strength.

Name of plant	Age of specimens	After 7 days from gauging: smallest excess over the minimum “norms,” kg	After 7 days from gauging: fluctuation downward in ordinary tests, kg	After 28 days from gauging: smallest excess over the minimum “norms,” kg	After 28 days from gauging: fluctuation downward in ordinary tests, kg
Yashkinsky	Age of specimens	5.25	13.76	12.56	10.12
Glukhoozersky	Age of specimens	2.88	6.8	13.60	9.05
Nevyansky	Age of specimens	9.4	8.7	14.0	8.0
Datsky	Age of specimens	12.44	10.23	20.1	8.32

Table No. 2.

Sand-cement tests for tensile strength.

Name of plant	Age of specimens	After 7 days from gauging: smallest excess over the minimum “norms,” kg	After 7 days from gauging: fluctuation downward in ordinary tests, kg	After 28 days from gauging: smallest excess over the minimum “norms,” kg	After 28 days from gauging: fluctuation downward in ordinary tests, kg
Yashkinsky	Age of specimens	2.66	5.61	4.6	7.75
Glukhoozersky	Age of specimens	4.17	3.95	5.48	6.02
Nevyansky	Age of specimens	1.74	9.28	1.15	8.56
Datsky	Age of specimens	7.92	9.28	10.45	5.2

In analyzing the tables given, it must be borne in mind that, according to the “technical conditions for acceptance of Portland cements” of 1911–1913, cement could be admitted for work already on the basis of seven-day tests; in that case the 28-day tests were carried out as supplementary ones.

The numerical data compared in Tables No. 1 and No. 2 show that, for seven-day specimens made of pure cement, the ratios are unfavorable for samples from the Yashkinsky and Glukhozersky plants; for 28-day specimens, all are favorable.

With respect to sand-cement specimens of both ages, there is only one favorable indication—for the Glukhozersky plant (the 7-day specimen). If not two adjacent specimens with different indications had been compared, but rather the maximum deviation recorded in the specimens of a given plant had been taken, the conclusion would have been still more unfavorable.

Thus, given the general instability in the course of the indications, there is no guarantee that the specimen following the one which gave a very low indication (close to the minimum), will necessarily show a deviation toward an increase, or that the jump toward a further lowering of the indications will be so small that the minimum of the “standards” will nevertheless be satisfied.

Hence the tendency of construction practice in responsible work to accept every delivery of cement and to put the latter into use only after a control test with satisfactory results is understandable.

Seventeen rejected batches were noted. The causes of rejection were: insufficient specific gravity—8 specimens; volume instability—5 specimens; a low value of the ratio of compressive strength to tensile strength—3 specimens; rapid setting was shown by 4 specimens. Most specimens were rejected for one unsatisfactory indication; several for two. Rejected batches sometimes stand apart, as a sporadic phenomenon, and in this case are of little significance for the work of the plant. Sometimes, however, successive batches were rejected (Yashkinsky and Nev’yansky plants), which characterized an entire period of the plant’s operation.

The presence of rejected batches in deliveries likewise argues for preliminary control verification, as does the instability of the indications of individual specimens.

The same instability of specimen indications, and sharp jumps approaching the minimum of the “standards,” are one of the reasons why, when standards for testing Portland cement are revised, the numerical values of the “standards” change over time in the direction of increase very cautiously, despite progress in the technology of cement production. For illustration, some “standards” from the standards of 1905, 1911–1913, and 1927 are given.

Table No. 3.

Date of establishment of the “standards”	Temporary tensile strength, kg/cm²: pure cement, after 7 days	Temporary tensile strength, kg/cm²: pure cement, after 28 days	Temporary tensile strength, kg/cm²: mortar: cement-sand—1 : 3, after 7 days	Temporary tensile strength, kg/cm²: mortar: cement-sand—1 : 3, after 28 days	Temporary compressive strength, kg/cm²
1905	20	25	7	9	By tensile strength: 9 × 8 = 72 or 9 × 10 = 90
1911–1913	25	30	9	12	not less than 100
1927	25	35	10	14	not less than 140

The broken lines of diagram No. 1—1-a, 1-b, 2-a, 2-b, 3 and 4—illustrate the revealed binding capacity of cement, insofar as its manifestation could be established under the conventional conditions of the tests. Namely:

1-a reproduces the readings obtained when testing specimens of neat portland cement for tensile strength after 28 days of curing;

1-b—the same after 7 days of curing;

2-a reproduces the tensile strength of specimens of the composition: cement–sand in a ratio of 1 : 3 by weight, at 28 days of age;

2-b—the same after 7 days of curing;

3—readings on the temporary compressive strength of sand-cement specimens (standard cubes) after 28 days of storage (1 day in a moist chamber and 27 in water);

4—gives calculated material on the ratio of compressive strength \((R')\) to tensile strength \((R)\) for sand-cement specimens of 28 days’ age (requirement of the “standards” of 1911–1913).

The comparatively large number of tests of portland cement from the Yashkino plant over 15 years gives a fairly complete and sufficiently distinct characterization of the products of this plant in the past, and at the same time of the plant’s own work.

The experimental material concerning the other plants, despite its scarcity, in comparative juxtaposition reveals interesting features of the product of these plants, which will become clear when the diagrams are considered.

The broken lines 1-a and 1-b in the part relating to the Yashkino plant have a wave-like contour, giving, at the very least, three rises with high maximum values: a rise in 1913–1914; a rise in 1915–1918; the last—the third—covers 1919–1917. In each rise we have maxima and minima of different significance.

The broken lines 2-a, 2-b and 3 have an analogous character, but without strict agreement.

The sections of the same lines for the cement of the Glukhoozerka plant, if one disregards fluctuations in readings around a certain mean value, are more uniform, and the values of the maxima and, correspondingly, the minima are lower.

For the cement of the Nev’yansk plant, 1-a likewise gives a rise for the middle of the section; 1-b, on the contrary, shows a course of the opposite meaning; the decline and maxima corresponding to 1-a are shifted toward the right branch, so that the maxima of 1-a correspond to the minima of 1-b.

Broken line 3 for the section of the Nev’yansk plant is characterized by a one-sided course toward a maximum in some agreement with the right branch of 1-b.

Lines 1-a, 1-b, 2-b and 3 for cement from Lanna (Olborg) proceed consistently, giving in the middle of the section a deep, but high in value, minimum; 2-a reflects it weakly in one reading; the remaining marks are opposite in meaning and the general course of the curve is a rise where the minima of the remaining lines occur. All values of the readings are high.

The readings of several cement specimens from the Katav-Ivanovsk plant in lines 1-a and 1-b give a sharp retreat toward a minimum in the middle; the course of the remaining lines 2-a, 2-b and 3 is analogous to 1-a and 1-b in the direction of change, but not in magnitude.

The course of the lines of readings for the cement of the Steffen and Kalmiret plant, with the small number of specimens, is not characteristic.

In addition to what has been noted above, in the course of considering the lines of the cements of the Glukhoozersk and Nev’yansk plants there is a special feature: the remoteness of broken curves 1-a and 1-b from one another. The same, though to a weaker degree, is also characteristic of curves 2-a, 2-b. Each pair of these broken curves demonstrates the course over time of the cement-hardening process, which in laboratory tests is recorded by two points: after 7 and 28 days. The farther, vertically, the 28-day points stand from the 7-day points, the greater the increase in strength of the specimen during the three-week interval following the vigorous hardening in the first 7 days; the smoother is the curve of increase in cement strength, with less possibility, so to speak, of running ahead, which in some cases is followed by a slowing of the hardening process and even a period of decline in the strength attained, both in neat-cement specimens and in sand-cement specimens.

A graphic illustration of what has been said is provided by the graphs of diagram III, constructed from the annual aggregate readings of the tested cements.

The course of the hardening process in specimens of cement from the Yashkino plant is well characterized by a tangled network of broken curves, where, among the 7-day and 28-day values that are very far apart from one another, very close points are encountered rather often, and even values of the opposite sense, i.e., where the tensile strength at 7 days exceeds that at 28 days. Such cases of degradation of cement strength after 7 days of hardening were observed at the Yashkino plant, over the whole period, 7 times for neat-cement specimens and once for sand-cement specimens. These cases are summarized in Table No. 4. In the tested cements of the other plants, no such cases of degradation of specimen strength were established.

Convergence of the tensile-strength readings for 7 and 28 days is essentially a phenomenon of the same meaning as degradation, but here the boundary has not yet been crossed, which has been noted for the Yashkino plant alone; the convergent values for 7 and 28 days are also more numerous at this plant; at the others—Datsky (Oolborg), Katav-Ivanovsky—they are isolated. The numerical material relating to this is given in Table No. 5.

For a critical assessment of the readings, summarized in the indicated Tables Nos. 4 and 5, that record a weakening of the cement-hardening process after 7 days, it is necessary to keep in mind at least the average value of the increase in specimen strength after 7 days over the following three weeks.

Of the foreign “standards,” only the French include a clause providing for the phenomenon described. It states: 28-day specimens of neat cement must have a strength greater than the 7-day specimens by not less than 5 kilograms, if the latter (7-day specimens) had not less than 55 kilograms per square centimeter (Karl Naske, Manufacture of Portland Cement. Ed. 1913. Russian translation, p. 336). In the Russian “standards” such a clause was not introduced and is also absent from the existing all-Union standard for Portland cement. Therefore, in further consideration of the phenomena described, we shall confine ourselves to comparison with the average readings on the increase in strength over the last three weeks of cement curing in laboratory tests, while not losing sight of the modesty of the requirement of the French “standards.”

The average increases in the readings after 7 days to 28 days for neat-cement specimens are as follows:

Cement	Increase
Cement of the Yashkino plant	8.53 kg/cm²
Cement of the Glukhozersk plant	15.10 kg/cm²
Cement of the Nev’yansk plant	10.32 kg/cm²
Cement of the Danish (Aalborg) plant	7.29 kg/cm²
Cement of the Katav-Ivanovsk plant	8.64 kg/cm²

For cement-sand specimens the same readings are:

Cement	Increase
Cement of the Yashkino plant	4.1 kg/cm²
Cement of the Glukhozersk plant	4.83 kg/cm²
Cement of the Nev’yansk plant	4.70 kg/cm²
Cement of the Danish (Aalborg) plant	4.45 kg/cm²
Cement of the Katav-Ivanovsk plant	4.63 kg/cm²

As we see, in terms of the magnitude of the average values of the quantities of interest to us, Glukhozersk cement occupies first place; it is followed by Nev’yansk, then Katav-Ivanovsk, Yashkino, and Danish. According to the average values, the cement of the Yashkino plant is not characterized so poorly, and the poor network of readings is explained by the alternation, at various points of the graph, of either lowered readings or readings of the opposite meaning. In order to obtain a satisfactory average, evidently, among the readings for 7 and 28 days there must be a considerable number of markedly distant ones, which would compensate, in deriving the average, for small differences or negative values of the increase in strength between 7 and 28 days of cement hardening.

In speaking of the significance for the quality of Portland cement of the noted phenomena of weakening of hardening after the 7-day period, both in neat-cement specimens and in specimens with sand, one must take into account the entire complex of readings for a given specimen, and especially those that establish the manifestation of the cement’s binding capacity: readings for rupture and compression.

The numerical material compared in this sense in Tables Nos. 4 and 5 permits the following conclusion to be drawn: the noted unsmooth course of hardening essentially has little effect on the final result. The grounds are as follows: according to the data of Table No. 5, item A, the weakened hardening of cement after the 7-day period in neat-cement specimens is not associated with a weakening of the binding capacity either in specimens with sand or in compression; the readings of both are satisfactory. In weak cements the whole complex of readings is reduced. Under item “B” of the same Table No. 5: a weakening of the hardening process in sand-cement specimens is not reflected in the temporary resistance to compression; the hardening of neat cement proceeds normally. Weak cements give a set of low readings.

The deviations from the above-cited average values of the increase in cement strength after 7 days in neat-cement specimens are quite considerable: the readings vary from 0.42 kg/cm² to 1.9. The rule of the French “standards” would prove applicable to only one specimen (item A 4).

In specimens with sand, the deviations from the average increase are less sharp; they vary from 0.1 to 1.75, with an average of 4.1 for the Yashkino plant, and are very reduced only in two cases (0.1 and 0.4).

Table No. 4 gives a summary of the test results from the Yashkino plant, with evidence of strength degradation in neat-cement specimens (7) and sand-cement specimens (1).

All these are strong cements, with values close to the maximum. The sand-cement tests of these cements, as in the phenomena of a simply weakened hardening after the seven-day period, progressively increase their strength almost normally; their tensile values are high; their temporary compressive resistance is high, and in some cases maximal or close to the maximum. In the table, for comparison, specimens close in test date and with a normal course of the hardening process are given. These normal-type tests in relation to specimens with sand are analogous to those in which the hardening process after 7 days proceeded with a reduction in the strength of the specimens.

Thus, within the limits of the available experimental material, here too, as with the phenomena of a weakened hardening process, it may be stated that degradation of the strength of cement specimens after 7 days does not substantially affect the final result in determining the binding capacity of Portland cement.

Table No. 6 brings together the numerical values of the maxima and minima of the test results for 28-day specimens, as an illustration of the amplitude of fluctuations in temporary tensile and compressive resistance in cements from various plants. Two maxima are given—respectively, minima—from each type of specimen, in order to reveal to some degree the stability of the extreme values. The accompanying values compared in the table with the extreme values provide material for orientation on the question of the significance of the maxima—and, respectively, the minima—as indicators of the binding capacity of the tested specimens of Portland cements.

The numerical material of Table No. 6 gives the following values for expressing the extreme amplitudes:

a) Neat-cement tensile specimens, 28-day.

Plant	Years	1) Principal maximum	2) Second maximum
Yashkino plant	1913–1914	60,6 − 44,58 = 16,02
Yashkino plant	1915–1918	67,55 − 42,56 = 24,99
Yashkino plant	1919–1927	64,5 − 41,9 = 22,60
Yashkino plant	(General) 1913–1927	67,55 − 41,9 = 25,65
Glukhoozersky plant	1913–1914	53,1 − 43,6 = 9,50	52,8 − 44,2 = 6,6
Nevyansk plant	1914–1918	58,21 − 44,05 = 14,16	56,39 − 46,17 = 10,22
Danish (Aalborg) plant	1914	59,7 − 50,11 = 9,59	59,39 − 51,07 = 8,32

b) Specimens from a cement–sand mixture 1 : 3; 28-day.

Plant	Years	1) Principal maximum	2) Second maximum
Yashkino plant	1913–1914	24,83 − 16,60 = 8,23
Yashkino plant	1915–1918	30,15 − 16,90 = 13,25
Yashkino plant	1919–1927	28,2 − 10,3 = 17,9
Yashkino plant		27,7 − 10,3 = 17,4
Yashkino plant	(General) 1913–1927	30,15 − 10,30 = 29,85
Glukhoozersky plant	1913–1914	24,27 − 17,48 = 6,79	23,75 − 17,62 = 6,13
Nevyansk plant	1914–1918	26,53 − 13,45 = 13,08	23,55 − 15,31 = 8,24
Danish (Aalborg) plant	1914	28,0 − 22,45 = 5,55	27,65 − 24,54 = 3,11

c) For tests of resistance to compression after 28 days.

1) Principal maximum.  2) Second maximum.

Yashkino plant 1913–1914: 310—169 = 141
  1915—1918: 372—161.3 = 210.7
  1919—1927: 310—132.5 = 177.5
  (General) 1913—1927: 372—132.5 = 239.5

Glukhoozersky plant. 1913—1914: 299—180 = 119  292—185 = 107

Nevyansk plant 1914—1918: 418—166 = 252  356—182.6 = 178.4
  356—166 = 190

Danish (Aalborg) plant. 1914: 354—278 = 76  353—320 = 32

By comparing the extreme values in the readings of the tests, it is established that the cement of the Yashkino plant, in tensile tests, gives amplitudes of deviations considerably exceeding those of all other plants. In compression tests, first place belongs to the Nevyansk plant, if one takes into account the only stable maximum over five years (418 kg/cm²). More stable and characteristic for the cement of the Nevyansk plant is the second maximum (356 kg/cm²). In the latter case the amplitude of deviations in the compression tests will prove to be maximal for the Yashkino plant. The cement of the Glukhoozersky plant has a reduced amplitude; for the Danish (Aalborg) cement, according to the second, more stable minimum (320), the difference between the maximum and the minimum must be considered insignificant, which characterizes the particularly stable properties of the cement of this plant.

Following, from Tables Nos. 6 A—B, the change in the readings conjugate with the maxima—respectively the minima—we state the following:

1. a) In the tables of maxima for tests of the Yashkino plant, coincidences of maximum readings occur in 2 cases: test Nos. 4—11 and 12—18; in one case there is a coincidence of the opposite sense: the maximum of the neat-cement tensile test corresponds to the minimum of resistance to compression (No. 2).

2. b) In the tables of minima for tests of the same plant in tension, we likewise meet only 2 cases of coincidences of one sense: test Nos., according to table 2—7 and 11—17; the opposite case, as above, relates to compression (test No. 14 corresponds to No. 2, 1-a).

3. In the readings of tests of cement from the Glukhoozersky plant, there are no coincidences of extreme values.

4. The cement of the Nevyansk plant gives one coincidence of maxima: test Nos. 4—6.

5. Danish (Aalborg) cement, with an insignificant number of tested batches (7), gives several combinations of direct and opposite meaning. Thus, the paired readings of tests Nos. 3—6 in the series of maxima and Nos. 1—5 in the series of minima have direct meaning. With the exception of one test, No. 2 in the series of minima, where there are no coincidences of extreme values in the conjugate quantities, all the others give combinations of the opposite sense, i.e., the maximum values of some quantities correspond to the minima of the conjugate ones.

The readings of cement tests from Denmark (Aalborg) are for the most part elevated, so that its minima are sometimes equal to or only slightly inferior to the maxima of the readings of Russian plants, and sometimes even exceed them. Thus, for cement–sand tests, the cement of the Kamyshet plant gives 18.87 kg/cm²; the minimum of the Danish is 22.45; the maximum of the same tests of the Glukhoozersky—

then 24.27 kg/cm²; the second minimum of the Danish cement is 24.54 kg/cm²; the maximum of the cement of the Kataev-Ivanovsk plant is 25.77 kg/cm². The maximum values of the indicators for the cement of the Yashkinsk plant are higher than those of the Danish cement, yet in the latter high values are consistently maintained, and especially the compressive strength (most above 320 kg/cm²). Therefore the picture of the mutual dependence of the values of the associated indicators is better outlined from the data on the cements of Russian plants. From a comparison of the table containing the maxima of the cements of Russian plants with the corresponding table giving the minimum values of the test indicators, it is clearly apparent that the maximum indicators of tests in the overwhelming majority are accompanied by a complex of high values of the indicators, though not necessarily maximum ones; the same applies to the minimum indicators. This coincidence of high—respectively low—indicators in one series of tests with correspondingly high or low indicators of another series associated with it is observed not only in cases of extreme indicators. A considerable number of examples of such noncoincidence could be drawn from the available experimental material also for tests with average values of the indicators. In carrying out the tests, attention was often drawn to cases where a cement with high indicators for neat-cement specimens gave low indicators for cement-sand mixtures in tension and compression, or with the opposite relationships. Thus, the indicators of one series of cement tests—for example, of neat cement in tension, or likewise of a cement-sand mixture—do not guarantee corresponding indicators, either in height or in meaning, in a series of associated determinations. Therefore, to characterize a cement, it is necessary to carry out an entire complex of determinations.

In the tables considered, along with the accompanying indicators, data are given everywhere on the fineness of grinding of the cement sample. The purpose of the standard requirement regarding the fineness of grinding of cement is that, for any quality of Portland cement, a sufficiently fine grinding guarantees an increase in the number of active (small) particles, the total action of which during hydration will be expressed in an increased manifestation of the binding capacity characteristic of the given cement in the first period of hardening. Fine grinding is only one of the conditions favorable for revealing the binding capacity of cement. For the given batch of cement used in construction, the grinding is fixed, and the binding capacity displayed by the cement corresponds to the degree of grinding established in testing. What properties the cement of the given batch would have at another fineness of grinding—this question remains open, since factory practice does not conduct experiments in this direction, and construction has to deal with the product as issued by the plants. Looking through the grinding column in the tables, it is easy to note that the Danish cement has the most stable and high fineness of grinding; after it, in terms of the insignificance of the amplitude of fluctuations for the selected samples, comes the Glukhoozersk cement. A more varied set of grinding indicators is given by the Nevyansk and Yashkinsk plants. Table No. 7 even gives a selection from the test records of samples with successively changing indicators of fineness of grinding, from the minimum to the maximum of the latter. The accompanying indicators of the given sample for tensile and compressive strength in no way correspond to the series of increasing values of fineness of grinding, and, in essence, cannot correspond, since the binding strength of cement depends substantially first of all on the qualities of the cement and only secondarily on the conditions influ-

…on the degree of its manifestation. A note on the fineness of grinding during the tests records the fulfillment of the minimum standards specified by the standard, and the presence of a certain quantity of fine fraction in the cement; however, to say that the given grinding of the tested batch of cement is definitely good is not possible from determinations carried out according to the methodology established by the standard.

With regard to the specific gravity of the tested cements, it may be noted that in the overwhelming majority of tests the requirements of the “standards” were satisfied. Among some tests of cement from the Nev’yansk plant, namely in the tests of 1918 (5 in number), there are very low specific-gravity readings—from 3.00 to 3.02 as against the minimum of the “standards,” 3.05. However, the cement of these batches gave very high readings for the tensile strength of cement–sand mixtures and the maximum compressive strength, with average and even minimal values for the tensile-strength readings of neat-cement specimens. The USSR standard of 1927 does not establish a numerical value for specific gravity.

There were 5 tests of cement with nonuniform change in volume and, consequently, of poor quality over the entire period of tests under consideration. It is necessary to point out here that the recorded nonuniformity of volume (the cake test, radial cracks along the edges) of the cement did not cause any special phenomena in the tested specimens—for example, destruction of specimens. In certain tests that did not show uniformity of volume expansion, one could note, after the 7-day period, a weakened increase in the strength of neat-cement specimens, while at the same time there was normal development of hardening in the sand–cement tests and high readings for compressive resistance. Theoretically, these facts of progressive increase in the strength of the specimens stand in contradiction to the observed signs of nonuniformity of volume expansion, by which the cement batch was assessed as falling outside the range of normal ones, and they make it difficult to assess the influence of nonuniformity of volume change on the course of the hardening process in these cements.

Diagram No. 4 illustrates the ratio of compressive resistance to tensile resistance of the tests, established by the “standards” of 1911–1913. With the exception of the tests of cement from the Yankinsky plant, which belong to the initial period of its operation and, consequently, to a still-unsettled technique, the remaining tested batches of cement satisfy this requirement of the “standards.”

In the all-Union standard of 1927 of the USSR this indicator was excluded, since its presence excluded from the category of normal cements of quite satisfactory qualities. Thus, if a cement had a tensile reading of 30 kg/cm² and a compressive reading of 220, then the ratio \(220 : 30 = 7.33\), as against 7.5 according to the “standards,” forced such cement to be recognized as not satisfying the requirements of the “standards,” i.e., to be rejected. The all-Union standard of 1927 replaced the ratio of resistances with a numerical value for compression of 140 kg/cm². This minimum would not have been met by 3 of the tested batches.

The analysis made of the data from laboratory tests of Portland cements used in the construction practice of Western Siberia permits the following conclusions:

1) The considerable majority (92.22%) of the tested batches of Portland cements supplied to the works satisfied the requirements of the “technical conditions for the acceptance of Portland cements” of 1911–1913.

2) The percentage of rejected batches (7.78%) is high. In light of the standard norms of 1927 in the USSR, this figure is reduced to 5.48%. (Under this standard, no value is assigned to the readings for specific gravity; 2.3% of the batches did not satisfy the requirements of the “norms” of 1911–1913 with respect to specific gravity.)

3) The readings of Portland cements in the individual determinations from sample to sample vary unevenly, but present a system of broken lines with sharp deviations wherever the “norms” do not confine the fluctuations within narrow limits. This deprives one of the possibility of confidently judging the qualities of the next batch or delivery of Portland cement on the basis of the readings of the preceding one, without control tests.

4) The agreement of paired readings (tensile strength, compressive strength; specific gravity, bulk density; fineness of grinding, normal quantity of water, setting) of a single sample, not without exceptions, is observed only in the direction of changes, but not in magnitude. No exact quantitative functional dependence between the readings of the paired determinations is discerned.

5) The phenomenon of retarded hardening and even degradation of the strength of neat-cement samples after 7 days up to 28 days, especially frequent in the samples from the Yashkino plant, does not substantially affect the course of the hardening process in sand-cement specimens (in tension and compression). The noted phenomenon is found mainly in strong Portland cements with predominantly increased fineness of grinding (82–84%, which for the cement of the Yashkino plant gives maximum, or close to maximum, fineness values).

6) Fineness of grinding, guaranteeing the number of particles of the active mass of the cement, is, for a given batch, a single but not the only good factor creating the optimum for revealing the binding capacity of the given cement.

7) The specific gravity of cement, lowered in comparison with the “norms” of 1911–1913 in some of the tested batches, and the inconstancy of volume did not have a noticeable influence on the development of cement hardening over the test periods.

8) The cements of the Yashkino and Nevyansk plants show periodic rises and falls over a number of years in the readings of their samples, which characterizes the uneven operation of the plants.

9) Cement from the Yashkino plant gives a significant number of convergent readings in paired determinations (tensile strength at 7 and 28 days) and, at the same time, large amplitudes of divergence, which characterizes the instability of the qualities of the plant’s product.

10) The cements of the Glukhoozersky and Nevyansk plants have a distinctive feature: a stable and high difference in tensile strengths at 7 and 28 days of hardening, characterizing, in comparison with others, an increased intensity of growth in the strength of specimens in the post-seven-day period, and a greater smoothness in the development of the hardening process, owing to which phenomena of retarded hardening of specimens after 7 days, or phenomena of degradation, are excluded.

11) Foreign cements (Denmark, Aalborg), finely ground, constitute a material of stable qualities with high, but not extreme, readings.

12) Cement from the Kamyshty plant gives readings close to the minimum of the “norms” and should be assigned to the category of weak cements.

Table No. 4.

Tests of accelerated hardening over 7 days with a decrease (degradation) of strength in the subsequent period up to 28 days.

Name of plant	No. of test	Pure cement: after mixing, after 7 days	Pure cement: after mixing, after 28 days	Pure cement: decrease in strength, kg/cm²	Cement–sand 1:3: after mixing, after 7 days	Cement–sand 1:3: after mixing, after 28 days	Cement–sand 1:3: decrease in strength, kg/cm²	Temporary compressive strength after 28 days, kg/cm²	Volumetric weight (flowed off up to 4900 holes/cm²) in %
A. Tests of pure cement.
Yashkinsky plant . . .	1	56,05	53,20	−2,85	14,7	21,4	—	203	81,68
Yashkinsky plant . . .	2	53,55	49,0	−4,55	18,78	22,7	—	229	82,41
Yashkinsky plant . . .	3	61,06	60,15	−0,91	21,73	24,28	—	354	82,45
Yashkinsky plant . . .	4	61,76	57,52	−4,24	20,29	24,07	—	372 *)	82,08
Yashkinsky plant . . .	5	59,45	59,30	−0,15	20,06	24,95	—	290,6	81,34
Yashkinsky plant . . .	6	58,20	56,52	−1,68	22,05	23,47	—	283	83,72
Yashkinsky plant . . .	7	57,35	54,54	−2,81	18,64	21,89	—	208,6	72,26
Ordinary tests of pure cement with a normal hardening process.
*)		48,0	57,47	—	20,39	25,07	—	318	80,05
*)		46,50	56,64	—	18,31	23,05	—	208,6	74,03
B. Tests: cement–sand 1:3; in tension.
Yashkinsky plant . . .	1	53,52	55,50	—	21,05	20,65	−0,4	227,6 *)	81,14
Ordinary test with a normal hardening process.
*)		51,55	54,55	—	16,22	25,22	—	213	78,79

Note. The bold figures in the column “temporary compressive strength” represent the maximum (372) and one of the partial minima (283). See Table No. 6.

Table No. 5.

Specimens of accelerated hardening during 7 days after gauging and of weakened hardening during the subsequent period up to 28 days, but with an increase in strength.

Name of plant	Specimen No.	Pure cement after gauging: 7 days	Pure cement after gauging: 28 days	Increase in strength over 3 weeks, kg/cm²	Cement–sand 1:3 after gauging: 7 days	Cement–sand 1:3 after gauging: 28 days	Increase in strength over 3 weeks, kg/cm²	Temporary compressive resistance after 28 days, kg/cm²	Fineness of grinding (passed through sieve 4900 holes/cm²), in %
A. Weakened hardening in neat-cement specimens.
1) Yashkinskii	1	54,30	55,20	+0,90¹)	16,92	20,72	—	239	79,0
1) Yashkinskii	2	49,67	51,04	+1,37	14,10	18,30	—	228	82,76
1) Yashkinskii	3	52,50	53,62	+1,12	16,35	21,85	—	246	83,31
1) Yashkinskii	4	61,65	62,07	+0,42	16,92	21,80	—	239	77,86
1) Yashkinskii	5	44,20	44,96	+0,76	12,92	16,81	—	149	79,15
1) Yashkinskii	6	40,0	41,90	+1,90²)	12,80	16,81	—	146	77,95
2) Katav-Ivanovskii	1	41,10	41,80	+0,70³)	19,20	25,6	—	279	83,85
3) Danish (Aalborg)	1	50,30	51,07	+0,77	21,5	36,15	—	347	88,77
B. Weakened hardening in cement–sand specimens 1:3.
1) Yashkinskii	1	51,40	63,10	—	18,90	19,95	+1,05⁴)	271	81,3
1) Yashkinskii	2	54,40	61,02	—	23,02	24,10	+1,08	230,3	81,7
1) Yashkinskii	3	58,20	56,52	weakened −1,68	22,05	23,47	+1,42	283	83,72
1) Yashkinskii	4	51,58	58,24	—	18,02	19,77	+1,75	232,7	74,72
1) Yashkinskii	5	39,45	44,02	—	13,27	14,64	+1,37	156,5	83,36
1) Yashkinskii	6	36,19	45,11	—	11,37	12,44	+1,07	156,5	82,61
1) Yashkinskii	7	36,64	48,95	—	10,20	10,30	+0,1	132,5	78,13
2) Danish (Aalborg)	1	50,01	54,60	—	26,20	27,65	+1,35⁵)	352	87,53

Note.
1) Average increase in strength after 7 days: 8,53 kg/cm².
2) ” ” ” ” ” 8,64 ”
3) ” ” ” ” ” 7,29 ”
4) ” ” ” ” ” 3,89 ”
5) ” ” ” ” ” 4,15 ”

Table No. 6.

Samples with maximum and minimum tensile and compressive values for cements from various plants.

A. Maximums of 28-day samples.

Sample No.	Pure cement after gauging, 7 days	Pure cement after gauging, 28 days	Cement-sand (1:3) after gauging, 7 days	Cement-sand (1:3) after gauging, 28 days	Time resistance to compression after gauging, 28 days	Fineness of grinding (passed through sieve 4900 openings/sq. cm) in %	Note
							1. Yashkinsky Plant.
							Pure cement. Tensile tests 1913–1914.
1	54.3	60.6 ¹)	17.57	21.08	236	78.63	*) minimums.
2	39.1	59.32 **)	16.9	19.4	171 *)	72.73	**) maximum.
							Same, 1915–1918.
3	47.4	67.55	18.1	25.21	237	79.03	¹) bold numbers in the table are maximums.
4	45.23	64.9 **)	21.9	28.2 **)	321	77.08
							Same, 1919–1927.
5	52.8	64.5	18.01	22.25	201.3	72.25
6	54.65	63.87	20.4	24.37	217	81.0
							Mortar: cement-sand 1:3; 1913–1914. Tensile tests.
7	44.1	55.42	18.92	24.83 ¹)	181	80.74
8	41.78	49.2	19.35	23.7 **)	244	88.0 **)
							Same, 1915–1918.
9	49.61	61.30	21.52	30.15	267	76.67
10	51.46	60.05	19.75	27.4	331	77.6
11	45.23	64.9 **)	21.9	28.2 **)	321	77.08
							Same, 1919–1927.
12	56.2	62.6	21.8	27.7 **)	310 **)	83.78
13	51.55	54.53	16.22	25.22	213	78.79
							Time resistance to compression, 1913–1914.
14	43.7	57.5	17.3	18.05	310 ¹)	74.03
15	47.32	57.35	18.35	22.72	283	74.44
							Same, 1915–1918.
16	61.76	57.52	20.24	24.07	372	82.08
17	54.19	60.70	18.75	24.25	371	77.08
							Same, 1919–1927.
18	56.2	62.6	21.8	27.7 **)	310 **)	83.78 **)
19	58.27	59.76	21.35	23.5	304	73.78

Continuation of Table No. 6.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark

2. Glukhoozersk Plant. 1913–1914.

Neat cement.                Tests in tension.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
1	41,08	53,1 ¹)	15,86	21,8	244,6	81,18	*) minimum.
2	35,40	52,8	14,05	17,95	218,0	77,53	**) maximum.

Mortar: cement–sand 1:3. In tension.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
3	32,87	46,4	17,80	24,27 ¹)	284,7	78,39	¹) bold numbers in the table are maxima.
4	27,88	48,87	16,52	23,75	266,7	78,78

Tests in compression.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
5	30,22	46,52	16.28	23,0	299,0 ¹)	76,59
6	29,30	49,32	17,45	23,5	292,0	76,35

3. Nevyansk Plant. 1914–1918.

Neat cement.                Tests in tension.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
1	39,21	58,21	13 71	18,21	255	71,85	*) minimum.
2	35,46	56,39	11,26	17,02	201	69,08 *)	**) maximum.

Mortar: cement–sand 1:3. In tension.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
3	42,86	48,89	19,51	23,55	295	77,34
4	44,45	49,97	19,85	26,53 **)	356 **)	90.2 **)	Spec. wt. 3,00. Defective.

Tests in compression.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
5	40,37	51,30	17,97	22,97	418	81,8	Spec. wt. 3,01. Defective
6	44,45	49,97	19,85	26,53 **)	356 **)	90,2 **)	Spec. wt. 3,00. Defective.

4. Cement from Denmark (Aalborg) 1914.

Neat cement.                Tests in tension.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
1	53,08	59,7 **)	16,92	22,45 *)	354 **)	86,93	*) minimum.
2	47,97	59,39 **)	21,05	24,54 *)	351 **)	88.77 **)	**) maximum.

Mortar: cement–sand 1:3. In tension.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
3	50,01	54,6	26,2	27,65 **)	352 **)	87,53
4	47,67	57,87	25,1	28,0	327	86,60
5	47,87	52,61	21,75	27,12 **)	320 *)	87.75

Tests in compression.

No. of sample	Neat cement, after gauging, 7 days	Neat cement, after gauging, 28 days	Cement–sand (1:3), after gauging, 7 days	Cement–sand (1:3), after gauging, 28 days	Setting time, from mixing to hardening, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), %	Remark
6	53,08	59,7 **)	16,92	22,45 *)	354 **)	86,93
7	50,01	54,6	26,2	27,65 **)	352 **)	87,53

Continuation of Table No. 6.

B. Minima of 28-day specimens.

No. of specimens	Pure cement after gauging, 7 days	Pure cement after gauging, 28 days	Cement–sand (1:3) after gauging, 7 days	Cement–sand (1:3) after gauging, 28 days	Temporary compressive resistance after gauging, after 28 days	Fineness of grinding (passed through sieve 4900 holes/cm²), in %	NOTE
							1. Yashkinskii Plant.
							Pure cement. Tensile tests, 1913–1914.
1	34,31	44,58 ¹)	11,66	17,86	194,7	70,90	*) minimum.
2	39,88	46,3 *)	14,2	16,6 *)	169	74,04	**) Maximum.
							The same, 1915–1918.
3	37,05	42,56	12,4	18,63	191	76,83
4	43,66	44,60	14,2	17,74	218	75,32
							The same, 1919–1927.
5	40,0	41,9	12,8	16,31	146	77,95	¹) Bold figures in the table are minima.
6	32,16	43,80	15,04	17,81	149,5	80,02
							Rupture of specimens with sand; 28 days. 1913–1914.
7	39,88	46,3 *)	14,2	16,6 *)	169	74,04
8	46,6	51,9	13,38	17,55 ¹)	206	83,24
							The same, 1915–1918.
9	40,1	47,36	14,74	16,90	174	69,88 *)
10	48,96	51,48	13,48	17,16	227	75,13
							The same, 1919–1927.
11	36,64	48,95	10,2	10,3 *)	132,5 *)	78,13
12	36,19	45,11	11,37	12,44	156,5	82,01
							Compression tests, 28 days. 1913–1914.
13	37,09	52,28	14,82	19,35	169 ¹)	74,19
14	39,1	59,32 **)	16,9	19,4	171 *)	73,73
							The same, 1915–1918.
15	37,96	48,8	13,56	17,7	161,3	77,16
16	40,08	50,96	14,23	18,07	173,6	72,93
							The same, 1919–1927.
17	36,64	48,95	10,2	10,3 *)	132,5 *)	78,13
18	39,19	45,27	13,95	15,35	138,3	79,43

Continuation of Table No. 6.

Sample No.	Neat cement: tensile strength after gauging, 7 days	Neat cement: tensile strength after gauging, 28 days	Cement–sand (1:3): tensile strength after gauging, 7 days	Cement–sand (1:3): tensile strength after gauging, 28 days	Temporary compressive resistance after gauging, 28 days	Fineness of grinding (passed through sieve 4900 openings/cm²), %	Remarks
2. Glukhoozersky Plant, 1913–1914.
Neat cement. Tensile tests.
1	36.80	43.60 ¹)	16.5	22.42	221	78.69	*) minimum.
2	33.22	46.2	16.75	21.10	243	76.73	**) maximum.
Mortar: cement–sand 1:3. Tensile tests.
3	32.67	49.85	13.5	17.48 ¹)	222	79.83	¹) bold numbers in the table are minima.
4	37.8	51.95	13.8	17.62	207.7	78.41
Compression tests.
5	36.07	51.2	13.17	18.8	180 ¹)	79.87
6	34.8	52.65	13.95	18.32	185	79.05
3. Nevyansk Plant, 1913–1914.
Neat cement. Tensile tests.
1	35.67	44.05	16.08	22.42	316	87.0	Specific gravity 3.02. Reject.
2	37.25	46.17	16.47	21.67	322	87.48	Specific gravity 3.02. Reject.
Mortar: cement–sand 1:3. Tensile tests.
3	36.17	54.4	10.85	13.45	208.3	75.97
4	41.1	54.82	10.74	15.31	255.0	71.74
Compression tests.
5	41.8	49.69	19.55	21.11	166.0	81.83
6	37.5	47.57	12.59	16.36	182.6	74.0
4. Cement from Denmark (Aalborg), 1914.
Neat cement. Tensile tests.
1	37.44	50.11 *)	18.51	26.28	278 *)	88.24	*) minimum.
2	50.30	51.07 *)	21.50	26.15	347	88.77 **)	**) maximum.
Mortar: cement–sand 1:3. Tensile tests.
3	53.08	59.7 **)	16.92	22.45 *)	354 **)	86.93
4	47.97	59.39 **)	21.05	24.54 *)	351 **)	88.77 **)
Compression tests.
5	37.44	50.11 *)	18.51	26.28	278 *)	88.24
6	47.87	52.61	21.75	27.12 **)	320 *)	87.75

Table No. 7.

Cement samples from different plants with minimum, average, and maximum indicators of fineness of grinding (passed through sieve 4900 openings/cm²).

Name of plant	Sample No.	Tensile strength: neat cement, 7 days	Tensile strength: neat cement, 28 days	Tensile strength: cement–sand, 7 days	Tensile strength: cement–sand, 28 days	Setting time after 28 days	Fineness of grinding (passed through sieve 4900 openings/cm²)	Remarks
Yashkinsky plant	1	40,1	47,36	14,74	16,9 *)	174	69,88 *)	*) minimum.
Yashkinsky plant	2	35,02	48,77	13,56	18,31	171 *)	70,0 *)	**) maximum.
Yashkinsky plant	3	33,95	47,4	14,95	18,8	204,3	75,58
Yashkinsky plant	4	49,05	58,92	19,14	25,07	316	78,4
Yashkinsky plant	5	33,4	45,32	16,4	19,76	186	78,0
Yashkinsky plant	6	42,67	58,37	20,95	24,92	305	78,0
Yashkinsky plant	7	56,2	62,6	21,8	27,7 **)	310 **)	83,78 **)
Yashkinsky plant	8	58,2	56,52	22,05	23,47	283 **)	83,72 **)
Yashkinsky plant	9	39,45	44,02	13,27	14,64	156,5	83,36
Yashkinsky plant	10	41,78	49,2	19,35	23,7	241	88,0 **)
Nevyansky plant	1	35,46	56,39	11,26	17,02	201	69,08 *)
Nevyansky plant	2	36,89	46,81	20,13	22,01	266	75,98
Nevyansky plant	3	36,17	54,4	10,85	13,45 *)	208,3	75,97
Nevyansky plant	4	42,92	49,21	17,0	22,02	233	79,08	Sp. gr. 3,00. Reject.
Nevyansky plant	5	40,37	51,3	17,97	22,07	418 **)	81,8	Sp. gr. 3,01. Reject.
Nevyansky plant	6	44,45	49,97	19,85	26,53 **)	356 **)	90,2 **)
Danish cem. (Aalborg)	1	47,67	57,87	25,1	28,0 **)	327	86,6 *)
Danish cem. (Aalborg)	2	37,44	50,11 *)	18,51	26,28	278 *)	88,24
Danish cem. (Aalborg)	3	47,97	59,39 **)	21,05	24,54 *)	351 **)	88,77 **)
Glukhoozersky plant	1	36,0	51,17	15,25	20,57	237	73 *)
Glukhoozersky plant	2	37,8	51,95	13,8	17,62	207,7	78,41
Glukhoozersky plant	3	37,94	52,3	17,15	21,5	231,3	82,3 **)
Katav-Ivanovsk plant	1	40,87	55,37	21,02	25,77 **)	343	85,3 *)
Katav-Ivanovsk plant	2	44,72	52,47	17,15	20,35	290	89,0 **)
Kamyshetsky plant	1	27,97	38,9	14,2	18,87 **)	161,3 **)	80,02 **)

Diagram I

Test data for Portland cement in the laboratory of the Siberian Technological Institute

Yashkino Plant

Data on the tensile strength of specimens made of neat cement.

kg/cm²

Years: 1913, 1914, 1915, 1916, 1918, 1919–20–21–22, 1923, 1924–25, 1926, 1927

Curves: No. 1a; No. 1b

Minimum of the 1913 standard for 28-day specimens made of neat cement
\((30 \text{ kg/cm}^2)\)

Data on the tensile strength of specimens made of a mixture of cement and sand in the ratio 1:3.

kg/cm²

Curves: No. 2a; No. 2b

Minimum of the 1913 standard for 7-day specimens made of a mixture of cement and sand 1:3
\((9 \text{ kg/cm}^2)\)

Minimum of the 1913 standard for 28-day specimens made of a mixture of cement and sand 1:3
\((18 \text{ kg/cm}^2)\)

Resistance of a cube with a pressure area of 50 cm² to crushing.

To the article by Instructor of STU—M. I. Meshcheryakov.

Cement

Guta from 1913 to 1927

Glukhoozersky
Nevyansky
Datsky
Stef.
Katav-Kamysh.
Ivanovsk.

1913
1914
1914
1915
1916
1918–27
1914
1923
1945–18
1913

kg/cm²

No. 1—16

Ratio 1:3. No. 2—26

kg/cm²

No. 3

Curve of the 1952 standards for 7-day specimens made from a mixture of cement and sand 1:3 (kg/cm²)

Compressive crushing resistance of a cube with a loaded area of 50 cm²

No. 3

Axis label: kg/cm²

No. 4

Axis label: %

Minimum of the 1952 standards (7.5–8.0)

Ratio of compressive strength to tensile strength at 28 days. No. 4

No. 5a

Axis label: %

Not more than 10%. Minimum of the 1952 standards

Cement fineness. Residue on a sieve with 900 openings per cm². No. 5a

No. 5b

Axis label: %

Minimum of the 1952 standards (not less than 75%)

Passed through a sieve with 4900 openings per cm². No. 5b

No. 6

Axis label: kg

Weight of 1 liter of cement. No. 6

No. 7

Axis label: h

Setting time. No. 7

Min.

No. 3

Vertical axis: kg/cm²
Scale marks: 150, 200, 250, 300, 350

[[graph consisting of plotted curves and vertical division lines; no further legible text]]

No. 4

[[graph consisting of several plotted curves and vertical division lines]]

Visible axis labels and scale marks:

• kg/cm²
• 10, 15
• %
• 0, 5
• %
• 0.7, 0.8
• %
• 100, 120
• mm
• 5

Setting time, No. 7

Initial setting, No. 8

Volume constancy, No. 9

Notation: — the given sample did not pass the volume-constancy test.

Specific gravity of cement, No. 10

Normal quantity of water for gauging neat cement, in [[unclear: unit/percent cut off]], No. 11

Normal quantity of water for specimens made from a mixture of cement and sand, in [[unclear: unit/percent cut off]], No. 12

No. 7
Minimum according to the 1913 standards: not less than 1/2 hour, not more than 12 hours.

No. 8
Minimum according to the 1913 standards: 20 minutes.

No. 9

No. 10
Minimum according to the 1913 standards: 3.05.

No. 11
Minimum according to the 1913 standards: 22%–30%.

No. 12
Minimum according to the 1913 standards: 8%–10%.

Chart in % — No. 11

[[unclear: beginning of label]] in the ratio 1:3. — No. 12

Axis labels visible: kg/cm²; mm; °C.

Diagram II

DIAGRAMS

of annual averages by plants.

Data on the tensile strength of neat cement.

Plants and years shown:

• Yashkinskii Plant: 1913, 1914, 1915, 1916, 1918, 1919, 1920, 1921, 1922, 1922, 1924, 1925, 1926, 1927
• Guroz Plant: 1913, 1914
• Nevyansk Plant: 1914, 1915, 1916, 1918, 1927
• Dantsig: 1914
• Sterlitamak: 1913
• Tula–Rva Novitskii Plant: 1914, 1915, 1918
• Tamlyshskii: 1915

Visible scale markings on the first diagram: 25, 35, 45, 55, 65.

Data on tensile strength

Visible scale markings: 10, 20, 30.

Specific gravities

Visible scale markings: 3.05, 3.10, 3.15, 3.20.

Data on compressive strength

Visible scale markings: 100, 150, 200, 250, 300, 350, 400.

Ratio of compressive strength [[unclear: cropped text]] after 28 days

Visible scale markings: 7, 8, 9, 10, 15.

Typo-lithography of the publishing house “Krasnoe Znamya”

DIAGRAMS

for the article by Prof. STU M. I. Metzgerakov.

of average annual data from various plants for one year.

Data on tensile strength of neat cement.

1913 — Yashkinsk., Glukhoz., Stroff., Kazan.

1914 — Yashkinsk., Glukhoz., Nev’yansk., Dat’skii, K.-Ivanov.

1915 — Yashkinsk., Nev’yansk., K.-Ivanov.

1916 — Yashkinsk., Nev’yansk.

1918 — Yashkinsk., Nev’yansk., K.-Ivanov.

1927 — Yashkinsk., Nev’yansk.

Note: The full height of the columns gives the tensile-strength value after 28 days; the lower part of the columns corresponds to tensile strength after 7 days.

Minimum standard, 1913: \(30 \text{ kg}/\text{cm}^2\)
Minimum standard, 1913: \(25 \text{ kg}/\text{cm}^2\)

mixtures of cement and sand in the ratio 1:3

Minimum standard, 1913: \(12 \text{ kg}/\text{cm}^2\)
Minimum standard, 1913: \(9 \text{ kg}/\text{cm}^2\)

of cements

Minimum standard, 1913: \(3.05\)

of a sand-cement cube

Minimum standard, 1913: \(100 \text{ kg}/\text{cm}^2\)

to tensile strength after setting

Minimum standard, 1913: \(7.5\text{–}8.0\)

Diagram III

COMPARATIVE DIAGRAMS

of the increase in strength of cement mortars

Annual averages of cements from different plants are compared

Data on tensile resistance

1913

• 7 days
• 28 days
• Sterofend
• Yashkinsky
• Sukhozersky
• Kamyshetsky
• Sterofend
• Kamyshetsky
• Pure cement
• Mix of cement and sand 1:3

1914

• 7
• 28
• Datsky
• Yashk.
• K.-Ivanov.
• Sukhoz.
• Nevyansk.
• Datsky
• Nevyansk.
• K.-Ivanov.
• Yashkinsk.
• Sukhoz.

1915

• 7
• 28
• Nevyansk.
• Yashkinsk.
• K-Ivanov.
• K-Ivanov.
• Yashkinsk.
• Nevyansk.

Yashkinsky plant

1919

• Yashkinsky
• Yashkinsky

1920

1921

Yashkinsky plant.

1924

1925

1926

Typo-lithography of the Publishing House “Krasnoe Znamya”

To the article by lecturer of STI—M. I. Meshcheryakov.

GRAMS

[[unclear: beginning of line cut off]] of mortars in the first 28 days.

[[unclear: beginning of line cut off]] plants by years of manufacture.

[[unclear: beginning of line cut off]] rupture.

1916

Visible curve labels:

• Nevyansk
• Yashkinsk
• K.-Ivanov.
• K.-Ivanov.
• Yashkinsk
• Nevyansk
• Yashkinsk
• Nevyansk

Visible axis markings: 28; 7; 28.

1918

Visible curve labels:

• Yashkinsk
• K.-Ivanovsk
• Nevyansk
• Yashkinsk
• K.-Ivanov.
• Nevyansk

Visible axis markings: 7; 28.

1922

1923

1927

Visible curve labels:

• Nevyansk
• Nevyansk

Designations:

— Cement of the Yashkinsk plant.
⋯ “ Glukhozersk plant.
– – – “ Nevyansk plant.
– · – “ Danish.
– · · – “ Steffens plant.
– — – “ Kamyshet plant.
– ··· – “ Katav-Ivanovsk plant.