FI62047C - BLINDING FOER FRAMSTAELLNING AV SYNNERLIGEN HAORDA CEMENTKONGLOMERAT - Google Patents

Description

l-inir-t fRl M ADVERTISEMENT. _ _, „^ I11) UTL.ÄGGNINQSSKIIIFT 62 04 7 (Section 4) Patent granted 10 11 1932

Patent meJJelat ~ (51) K * .ik? /Int.a. C W B 13/24, 7/352 FINLAND —FINLAND (21) P »** nttltMk * imi · - PK« tcam6knln | 793301 * (22) Hikemliplhrl — AmMuilngadti 2k .10.79 '' (23) Alkupllvl — ClWfhMidai O8.O6.76 (41) Tullut lulklMkal - BIMt affmtllg 2b 10 79 NM— I · nUMwIMIMm wh rtgiittritynlnn Aiw n pubiiewad 30.07.82 (32) (33) (31) * n4 *** y «» ***> · —prlorltM 13.06.75

Italia-Italien (IT) 8 ^ 13 ^ A / 75 (71) Master Builders (Europe) N-.V., Nijverheidsweg z / n, 39 ^ 9 Oostham,

Belgium-Belgium (BE) (72) Mario Collepardi, Roma, Italy-Italy (IT) (7I +) Leitzinger Oy (5I +) Mixture to form high-strength cement conglomerates -

The present invention relates to the production of high-strength cement conglomerates, such as high-strength cement conglomerates.

The mechanical strength R of the concrete and the weight ratio (w / c) between the water and the cement in the mix are well related by the ratio: * 1 R * - (Abram's law) w / c * 2 where Ki and K2 are constants depending on the type of aggregate and binder, filler to binder ratio, temperature and cure time.

U.S. Patent No. 3,350,225 describes a cement mix additive which is polyvinylpyrrolidone and the sodium salt of formaldehyde condensed naphthalenesulfonate. The purpose of the additive is to improve the flowability of the cement mixture when the mixture is pumped in pipes. Thus, the additive does not affect the compressive strength of the cement, in some cases it even lowers the compressive strength. U.S. Patent No. 2,892,728 mentions, inter alia, that various condensation products of naphthalenesulfonic acid can be used to improve the plasticity of cementitious mixtures, however, the use of these additives adversely affects other properties of the mixture.

U.S. Patent 3,582,376 describes a fast-curing cement mix containing cement, gypsum and a dispersant. The preferred dispersant is the condensed sodium salt of sulfonated naphthalene formaldehyde, but other dispersants such as lingosulfonates, gluconic acid and saline solutions of condensed naphthalenesulfonic acid may also be used. The curing of the mixture can be accelerated by the use of suitable additives such as potassium sulfate, calcium chloride, sodium chloride and sodium hydroxide. Curing can be slowed by the use of calcium lignosulfonate, glucose, sucrose and borax.

A cement mixture as described above is also disclosed in U.S. Patent 3,885,985, according to which esters of fatty alcohols such as sulphates, for example ammonium sulphate esters, aromatic sulphonates such as ammonium, alkali and alkaline earth aromatics, saponified phenols can be used as emulsifiers. or naphthenic acids. Anionic or nonionic emulsifiers can also be used, such as liquid or solid alkaryl polyoxyalkylene alcohols and their derivatives, such as their esters, for example ammonium sulphate esters and hexitol anhydride - polyoxyethylene derivatives of partially long chain fatty acid esters. In this known mixture, carbohydrates such as monosaccharides, for example glucose and fructose, disaccharides, for example lactose and sucrose, trisaccharides, for example raffinose, polysaccharides, for example, starch and cellulose acid, starch and cellulose, pregelatinised starch, , such as tartaric acid and mucic acid.

However, these known mixtures do not achieve satisfactory hardness under all conditions. Surprisingly, it has now been found that by using certain types of components known per se in combination, a very strong end product is obtained.

It is also known that additives can be added to mixtures of inorganic binders which make the mixture more fluid and thus 3 62047 reduce the amount of mixing water and increase the mechanical strength of the concrete thus obtained.

According to the invention, cement conglomerates (intermediate masses, mortars, concretes and the like) which give better mechanical properties compared to known conglomerates are prepared by adding to a mixture of water, binder and aggregates a mixture containing: - 5 to 99.8% by weight of polymer containing obtained by polycondensation of formaldehyde with an aromatic series of sulphonic acids, free or in the form of a salt and soluble in water (component No 1), - 0,1 to 65% by weight of a starch hydrolysis product obtained from a vegetable material such as maize, wheat, rice, potatoes, etc. (component No. 2) and - 0.1 to 65% by weight of a water-soluble inorganic electrolyte of alkali metals and / or ammonium (component No. 3).

In the following, the present invention will be explained in more detail in general and by means of some embodiments given by way of non-limiting examples.

The first essential component of the mixture according to the invention (component No. 1) is preferably formed from a polycondensate of formaldehyde with sodium naphthalene sulfonate of the α- or β-type or a mixture of the two. It can be represented by a formula

CH - CH Γ CH - CH

✓ s y x

CH 2 CH - CH 0 - CH NCH - · H

\ / 2 \ /

CH = CH CH = CH

/ \ / \

CH CH CH CH

X s x S

X CH - CH 2 CH - CH 2

I I

SO-jNa SOjNa n where n = 1, 2, 3, .... The second essential component (component No. 2) of the mixture according to the invention consists of a polyglucosaccharide prepared by hydrolysis by means of acid, heat or enzymes of starch obtained from any raw vegetable material, such as maize, wheat, rice, potatoes etc., and which best contains polysaccharides having a degree of polymerization of 3 to 7 glucose units. In particular, commercially available hydrolyzed starches containing 30% by weight of polysaccharides with 3 to 7 glucose units can be used.

The third essential component (component No. 3) of the mixture according to the invention consists of a water-soluble inorganic electrolyte of alkali metals and / or ammonium to improve the ionic strength of the aqueous solution, the component preferably being an alkali metal such as sodium or ammonium carbonate, bicarbonate, chloride, sulphate, nitrate, nitrite, phosphate, pyrophosphate, metaphosphate, polyphosphate, borate or hydroxide.

The amount of components Nos. 1, 2 and 3 in the mixture can vary within wide limits, as can be seen from the following general mixture by weight (in% by weight)

Component No. 1 5.0 to 99.9%, preferably 30 to 90%

Component No. 2 0.1 to 65.0%, preferably 1 to 10%

Component No. 3 0.1 to 65%, preferably 5 to 60% The mixture thus obtained can be added to the cement mixture 0.01 to 3%, preferably 0.1 to 1.0% by weight of the binder, which may be Portland cement together with pozzolan. , with or without fly ash, ground quartz, blast furnace slag, aluminum cement, gypsum or other inorganic binders.

With this cement mix, self-leveling concretes can be prepared, i.e. highly flowable concretes (depression 20-35 cm) with a very low water / binder ratio, negligible loss of workability over time, and unusually high strength compared to concrete made using a single component and surprisingly high compared to unmixed concrete.

The following examples show that, although the use of individual components in the manufacture of cement conglomerates is known, it is possible to obtain a fresh mix while maintaining a constant workability when using a mixture of component No. 1, No. 2 and No. 3 when comparing unusually high performances. performances that can be achieved with just a single component, and surprisingly higher compared to unmixed concrete.

Example 1

The purpose of the example is to demonstrate the good fluidizing effect of the mixture according to the invention. The evolution of the fluidization efficiency of the component mixture was performed by measuring the flow of mortar on a drip table (UNI standard) according to the Italian laws on hydraulic binders (GU No. 180, 17.7.1968, DM 3.6.1968, Article 10), ie the mixture contained 450 g cement, 225 g water and 1350 g Torre del Lago sand.

Table 1 shows the results obtained with Portland 425 cement. The first three columns show the percentages of the mixture of mixture components No. 1, 2 and 3. The fourth column shows the amount of mix added as a percentage of the weight of the cement and the fifth column shows the flowability of the mortars.

Table 1: Flowability of cement mortars as assessed by their spread.

Component Component Component Mixture / Flow No. 1 No. 2 No. 3 Cement (mm) (%) _ (%) _ (%) _ (%) _ --- 0.0 90 100 0.3 145 - - 100 --- 0,3 120 --- --- 100 0,3 85 70 20 10 0,3 165 100 0,6 170 --- 100 --- 0,6 145 --- --- 100 0.6 80 70 20 10 0.6 200

Component No. 1: Polycondensate of the sodium salt of β-naphthalenesulfonic acid (CH 2 Cl 2) with formaldehyde (Cl 2 O) Component No. 2: Hydrolyzed starch syrup containing 40% polysaccharides with 3 to 7 glukoosiyk-sikköä

Component No. 3: sodium carbonate (Na 2 O 2) 6 62047

The results show the fluidization efficiency of the mixture according to the invention. The fluidity increases by more than 80% (0/3% of the mixture) and more than 120% (0.6% of the mixture) compared to a mixture without a mixture.

The results obtained also show that the mixture according to the invention has a better fluidization efficiency than the mixture formed by the individual components and in particular the polycondensate of the sodium salt of β-naphthalenesulfonic acid together with formaldehyde.

Example 2 This example demonstrates the synergistic effect of the mixture according to the invention, especially if component No. 3 is sodium chloride. Components Nos. 1 and 2 are described in Example 1. The weight percent of each component of cement is shown in Table 2.

In all concretes containing mixtures, the amount of water was such that well-flowing concretes with a deflection of 21 cm were obtained. Concrete alone without the mixture was prepared by depression of about 10 cm to account for both advantages of the present invention: Better flow when fresh and better strength when cured.

Figure 2 shows the strength of the concretes at 1, 7 and 28 days: The values in parentheses show an increase in strength compared to the strength of concrete without a mixture.

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Table 2: Strengths of concretes prepared according to Example 2.

The values in parentheses indicate the percentage increase in compressive strength compared to ordinary concrete without mix.

Seos Καηρ. Καηρ. Karp. water / pressure Compressive strength No.: No. 1 No. No. 2 No.: 3 cement Mon (kg / cmz (%) (%) (am) 1 day 7 days 28 days 1 - - 0.46 10.5 61 (0) 305 (0) 453 (0) 2 - - 0.300 0.51 21.0 75 (23) 305 (0) 419 (-8) 3 - 0.015 - 0.50 21.0 65 (6) 318 ( 4) 403 (-11) 4 0.400 - - 0.37 21.0 105 (72) 472 (55) 634 (40) 5 - 0.015 0.300 0.51 20.5 69 (13) 326 (7) 432 (-) 5) 6 0.400 - 0.300 0.36 21.5 130 (113) 528 (73) 630 (39) 7 0.400 0.015 - 0.36 21.5 126 (106) 534 (75) 673 (48) 8 0.400 0.015 0.300 0.36 21.0 147 (141) 558 (83) 722 (66)

Component No. 1: Polycondensate of the sodium salt of 8-naphthalenesulfonic acid (C Component No. 2: Hydrolyzed starch syrup containing 40% polysaccharides with 3 to 7 glucose units. Component 3: Sodium chloride (NaCl).

These values indicate the synergistic effect of ternary mixture No. 8 prepared according to the invention. In fact, the improvement in strength achievable with this mixture is greater than the results obtained by adding together the increases produced by each component. For one day, the percentage improvement in strength with the applicant's mixture (mixture No. 8) is 141%: This is worthless than the sum of the increases obtained with the individual components (23 + 6 + 72). The same results can also be observed at 7 and 28 days.

Example 3 The purpose of this example is to demonstrate the fluidizing effect of a mixture according to the invention on fresh concrete.

The following ingredients were mixed together: 8 62047 - Sand (maximum diameter 5 mm) 55.00 kg - Gravel (maximum diameter 50 mm) 82.50 kg - Ordinary Portland cement (type 325 kg / cm2) 26.25 kg Particle size of aggregates used the distribution is shown in Table 3.

Table 3; Particle size distribution of fillers

Diameter O - 0.3 0.3 - 1.2 1.2 - * 2.5 2.5 - 5 _ (mm) _

Sand% 27 32 16 25

Hall (™ f3a 5 '10 10 - 15 15 - 30

Sora ....... ...—-% 17 35 48 ---

Water (12.5 liters) was added to the mixture to give a concrete with a workability of 5 cm after 3 minutes of mixing. A mixture having the composition shown in Table 1 was added to the concrete thus prepared.

The amount of mixture was 0.6% by weight of cement. After stirring for another 2 minutes, the workability of the concrete corresponded to a depression of 23 cm.

It was cast into 10x10x10 cm molds as test pieces which were cured at 20 ° C and 65% relative humidity. No compaction was required in the manufacture of these specimens due to the high flowability of the concrete.

Another concrete was also prepared which did not contain the mixture but sand, gravel and cement in the proportions given above.

The addition of water (16 liters) was adjusted in such a way as to obtain concrete with a lower workability (depression: 12 cm) than concrete containing the mixture. Test pieces of 10x10x10 cm were prepared, hand-sealed and cured at 20 ° C at 65% relative humidity.

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The mechanical strengths of the specimens obtained from each concrete, which had been cured for 1, 3, 7 and 28 days, were tested, the results of which are given in Table 4.

Table 4: Properties of concretes containing and not containing the mixture according to the invention 2. . Depression Compressive strength (kg / cm) V0S1 / (cm \ cement '' 1 37 28 days days days days

Concrete containing the mixture 0.48 23 140 335 451 565

Concrete without mixture 0.61 12 83 178 282 386

Concrete without mixture 0.48 5 106 208 315 432

The results in Table 4 show that by adding the mixture according to the invention, both the workability and the mechanical strength of the concrete can be improved at the same time. In particular, it is possible to produce concrete with admixtures which, although self-leveling (indentation: 23 cm), have considerably higher mechanical strength than non-admixtured, less workable concretes (indentation: 12 cm).

Furthermore, for concretes prepared using the same water / cement ratio, it is shown that concrete containing the mixture according to the invention gives higher mechanical strength. This shows that the increase in mechanical strength obtained by adding the mixture according to the invention is not only due to a decrease in the water / cement ratio, as might be inferred from Abram's law, but is also due to a higher degree of hydration of the cement.

Example 4 This example shows that the mixture prepared according to the invention containing components No. 1, No. 2 and No. 3 (described in Example 2) can advantageously also be used in steam curing of concretes, in particular without prior curing at room temperature.

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Three concretes were prepared with the same workability (weight = 20 cm) and the amount of cement 400 kg / ra. All concretes were prepared using the same high-strength cement, sand, and aggregates, but using a different water / cement ratio (shown in Table 5) to achieve the same workability. The first concrete was made without a mixture? the second concrete contained only component No. 1 (0.60% by weight of cement); the third concrete contained a mixture prepared according to the invention (0.60% by weight of cement): The composition of this mixture is shown in Table 5.

Immediately after mixing, the fresh concrete was poured into 10x10x10 cm molds and the resulting specimens were heated so that the temperature rose from 20 ° C to 70 ° C in 3 hours. After three hours of steam treatment at 70 ° C, the concretes were cooled for 1 hour at room temperature, after which the compressive strength was measured. Second specimens made of the same concretes were kept at room temperature after the above steam curing and the strength was determined on day 7.

Table 5: Strengths of concretes cured with steam without prior curing at room temperature _

Kompo- Kompo- Kompo- 7ΖΓ / Water / Press- Compressive strength nent nent nent cement cement. g / cm 2: No. 2 No. 3 (%) (%) Cm 7 hours 7 days (%) (%) (%) _ 00 0 0.00 0.55 20 143 362 100 O 0 0.60 0.40 20 178 640 60 3 37 0.60 0.37 20 390 702

Component No. 1 as in Example 1

Component No. 2 as in Example 1

Component No. 3 Sodium Chloride (NaCl)

The results shown in Table 5 show the advantageous faster development of strength during the early curing phase (7 hours after steam curing) and at the same time the development of higher strength during the later curing phase (after 7 days).

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Example 5

Concretes were prepared using the mixture and without it / containing highly durable Portland cement (425 kg / cm 2) at 400 kg / m · * and using the type of sand and gravel described in Example 3. The sand content was 38% of all fillers.

The water / cement ratio of the concretes was determined so that the indentation was 9.0 + 1.0 cm. The mixture used is the same as in Example 1.

The concrete was then poured into 10x10x10 cm molds into specimens which were treated with steam as follows: 3 hours pre-curing at 20 ° C, 2 hours raising the temperature from 20 ° C to 75 ° C in the presence of saturated steam and 1 hour cooling the specimens at 25 ° C teen. The concretes were broken by compression 12 hours, 3 days, and 28 days after the start of the thermal cycle.

Mechanical strengths are given in Table 6.

Table 6: Effect of the mixture according to the invention on the mechanical strength of concrete in low-pressure steam curing 2 Compressive strength (kg / cm)

Mixture / Water / cement cement 12 hours 3 days 7 days 28 days (%) '0.0 0.45 175 291 384 441 0.5 0.39 263 402 428 528 1.0 0.37 231 390 432 537 These results show that the addition of the mixture increases the mechanical strength of steam-cured concretes after both short and long curing times. V ..

Example 6 The purpose of this example is to illustrate the benefits of using sodium sulfate as component No. 3 in steam-cured concretes. For this purpose, concrete containing 1% seofet was prepared. In the first mixture, the composition of 12,62047 is shown in Table 2, component No. 3 was sodium carbonate, the salt of which is preferably used for curing concretes at room temperature, while in the second mixture, component No. 3,011 is sodium sulfate in equal amounts. The concretes were prepared and cured in the same manner as in Example 4. The mechanical strengths obtained are given in Table 7.

Table 7: Effect of the mixtures according to the invention on the mechanical strength of low-pressure steam-cured concrete

Vegiy _Compressive strength (kg / cm) _ cement 12 hours 3 days 7 days 28 days 1st mixture (containing Na 2 CO 3 0.37 231 390 432 537 2nd mixture (containing Na 2 SO 4) 0.37 243 401 446 539

The results obtained show that Steam-cured concretes give Higher mechanical strength if component No. 3 of the mixture is sodium sulphate.

Example 7 The purpose of this example is to demonstrate the effect of a mixture according to the invention on the mechanical strength of autoclaved concretes. For this purpose, concretes containing 500 kg / m 3 of mechanically strong Portland cement (425 kg / cm 3) were prepared using the aggregates described in Example 3 and a mixture having the composition shown in Table 1.

10x10x10 cm test specimens were prepared from these concretes and treated with the following thermal cycle: 3 hours pre-curing at 20 ° C, 4 hours raising the temperature from 20 ° C to 190 ° C, 3 hours at 190-6 saturated steam and 3 hours cooling 190 ° C to 25 ° C.

Twelve hours after the start of mixing, the test pieces were broken by compression. The results are shown in Table 8.

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Table 8: Effect of the mixture according to the invention on the mechanical strength of autoclaved concrete

Mixture / Compressive strength cement (kg / cm 2) (%) ______ 0 655 0.5 906 1 958

The results obtained show that the addition of the mixture according to the invention increases the strength of the autoclaved concretes.

Claims (11)

1. A mixture for the production of particularly hardened cement conglomerates which are cured at room temperature or with meadow, characterized in that the blend contains: the aromatic series, which is free or in the form of a salt and water-soluble (component # 1), - 0.1 - 65% by weight of a starch hydrolysis product obtained from any plant material, such as e.g. corn, wheat, rice, potatoes, etc. (Component No. 2) and 0.1 - 65% by weight of an inorganic water-soluble electrolyte (Component No. 3) of alkali metals and / or ammonium. 2. The mixture according to claim 1, characterized in that the component # 1 refers to a polymer obtained by polycondensation of formaldehyde with naphthalenesulfonic acid of - or type (or its sodium salt). 3. The mixture according to claims 1 and 2, characterized in that the component # 2 refers to a polyglucosaccharide (CgH 2 The mixture according to claims 1 and 3, characterized in that the component # 2 refers to a hydrolyzed starch containing at least 30% by weight of polymers having a degree of polymerization between 3-7. The mixture according to claim 1, characterized in that the component 3 refers to a sodium salt of an acid selected from at least one group consisting of carbonic acid, nitric acid, nitric acid, phosphoric acid, metaphosphoric acid, polyphosphoric acid, hydrochloric acid, sulfuric acid, sulfuric acid. pyrophosphoric acid. The blade according to claims 1 and 5, characterized in that the component # 3 is sodium sulfate.