SK279520B6 - Binder based on a grinded clinker of portland cement - Google Patents

Abstract

A binder contains a clinker of the portland cement, with a surface area of 450 - 700 m2/kg, and 0.2 - 5 percent by weight of a lignin derivative selected from the group containing ligninsulphonate, sulphonated lignin, where weight percents are stated with respect to the clinker weight. A pH of the lignin derivative, in the form of 10 percent solution, ranges from 7.5 to 11. The binder may further contain: up to 8 percent by weight of alk. metal salts; up to 40 percent by weight of latently hydraulic substance, e.g. granular scar or power-plant flue ash; up to 20 percent by weight of a very fine amorphous SiO2; up to 10 percent by weight of thermally activated earths, at a temperature 600 - 900 degrees Celsius and with a particle size being smaller than 150.10exp(-6) m, e.g. thermally activated kaolins, kaolin clays, claystones, montmorillonitic clays and bentonites, kaoline-illitic clays, refractory clays, ceramic slips and set inhibitors of gypsumless cements.

Description

Technical field

The invention relates to a binder based on ground clinker of Portland cement, where the regulating effect of gypsum is replaced by other additives.

BACKGROUND OF THE INVENTION

Gypsum-free cement has improved properties over conventional Portland cement due to the possibility of preparing materials with a low water coefficient while maintaining good workability. It is known from U.S. Pat. No. 3,689,297 (Brunauer) to formulate a free-flowing expandable slurry, mortar or concrete based on ground cement clinker having a surface area of 600 to 900 m ² / kg containing at least 0.002 parts grinding additive and at least 0.0025 parts alkaline lignin sulfonate or alkaline earth lignin sulfonate sulfonated lignin and at least 0.0025 parts of alkali carbonate, the aqueous coefficient being in the range 0.20-0.2. As a grinding additive, a substance with polar and non-polar groups in the molecule is specified.

Further, US 4,168,985 (Kolar, Slag) discloses a cementitious binder composition consisting of a cement having a specific surface area of 250 to 3000 m ² / kg containing 5 to 95 wt. % of particles smaller than 5.10 ^-6 m, at least 0.0025 wt. % lignin compound, 0.001 to 8 wt. % alkali metal salt and 0.05 to 80 wt. water. U.S. Pat. No. 4,551,176 (Slag et al.) Discloses a composition of a fast setting cementitious binder having a specific surface area of 150 to 300 m ² / kg containing 5 to 95 wt. % of particles smaller than 5.10 ^-2 m, 0.1 to 5 wt. % water-soluble sulfomethylated condensate with trivalent cation-doped formaldehyde, and 0.1 to 10 wt. alkali metal compounds, e.g. alkali hydroxide, carbonate, bicarbonate, silicate.

U.S. Pat. No. 5,076,851 (Slag et al.) Discloses a composite binder composition containing 60 to 96.7% by weight of binder. % Portland cement clinker ground to a specific surface of 350 to 550 m ² / kg and 3 to 40 wt. latent hydraulic substances, such as granulated blast furnace slag, fly ash, and the like, wherein the two substances are ground in the presence of 0.01 to 0.1 wt. 0 to 20 wt. % amorphous SiO ₂ , 0.1 to 3 wt. % sulfonated polyelectrolyte, for example sulfonated polyphenate, lignosulfonan and 0.5 to 6 wt. alkali carbonate, bicarbonate, hydroxide.

U.S. Pat. No. 5,125,979 (Slag et al.) Discloses a method for grinding gypsum-free Portland cement, which comprises grinding Portland cement clinker with additives of 0.01 to 0.05% by weight. a synthetic surfactant stable in an environment of pH 9-12, for example dodecylbenzenesulfonic acid triethanolamide. In addition to clinker and the alkali metal compound, an integral part of the gypsum-free cements is also a sulfonated polyelectrolyte, for example lignosulfonate. The random choice of this lignosulfonate (from various commercial products) does not always give good results when applying gypsum-free cements. With such a random choice of lignin sulfonate as an additive to gypsum-free cements, the initial (4 to 24 hour) strengths are often reduced.

SUMMARY OF THE INVENTION

These disadvantages are overcome by a binder based on ground Portland cement clinker containing Portland cement clinker having a specific surface area of 450 to 700 m ² / kg and 0.2 to 5 wt. a lignin derivative selected from the group of ligninsulfonan, a sulfonated lignin, the nature of which is that the pH of the lignin derivative in the form of 10 wt. % of the solution is in the range of 7.5 to 11. The binder further comprises 0 to 8 wt. % alkali metal salts of carbonates, bicarbonates, silicates and / or hydroxides, up to 40 wt. % of latent hydraulic substances, such as granulated blast furnace slag or power ash, up to 20 wt. % high-grade amorphous SiO ₂ , in the form of SiO ₂ drift from metallurgical products, up to 10 wt. thermally activated earth, at a temperature of 600 to 900 ° C, with a particle size of less than 150 x ^{10 6} m, such as thermally activated kaolins, kaolin clays, claystones, montmorillonite clays and bentonites, kaolinitic-illite clays, refractory clays and ceramic slurries; containing solidification retarders for gypsum-free cements such as boric acid, sodium potassium tartrate or derivatives of organic hydroxy acids, extracted to the weight of clinker.

Systematic physicochemical studies have shown a negative impact of some lignosulfonates on the properties of gypsum-free cements (especially on initial 4 and 24 hour strengths). Low pH ligninsulfonates in solution together with Na ₂ CO ₃ do not create conditions for the formation of high strength hydrates at the beginning of hydration. In order to achieve high initial strengths of slurries, mortars and concretes, the pH of the additive solutions used in their preparation is particularly important. Furthermore, it has been found that the addition of sodium carbonate in the range of concentrations used does not affect the pH of the lignin sulfonate-containing solution. Thus, the final pH of the additive solution is highly dependent on the pH of the starting lignosulfonan solution. The above findings and experimental results have clearly indicated the need to use those types of lignosulfonates having a pH of above 7.5 (i.e. in the alkaline range) in solution (e.g. in the form of a 10 wt% solution).

DETAILED DESCRIPTION OF THE INVENTION

The invention is illustrated by the following non-limiting examples.

All percentages given in the examples are weight percent based on the weight of clinker.

Example 1

Gypsum cement with a surface area of 510 m ² / kg ground from the clinker of conventional Portland cement in the presence of 0.05% by weight was used to prepare the slurry w = 0.25. dodecylbenzenesulfonic acid alkanolamide. The slurries were prepared with 1.25 wt. % Na ₂ CO ₃ and 1 wt. lignosulfonate (in cement weight). A number of commercial lignosulfonates, mainly sodium salts, were used in these experiments. In tab. 1 shows the strength results after 2 and 24 hours depending on the pH of the 10 wt. lignínsulfonánu.

Table 1

Labeling lignosulfonan pH of a 10% lignosulfonan solution % accompanying monosaccharides Compressive strength (MPa) 2 hrs 24 hours A 3.1 8 0 5.8 B 3.8 6 0.1 8.9 C 6.4 2 1.2 15.8 D 7.0 2 2.5 25.1 E 7.8 2 3.5 30.2

F 8.1 2 5.2 50.5 G 8.2 2 6.8 52.3 H 8.4 2 5.9 54.8 I 8.8 2 5.9 59.8 J 10.5 1 6.2 58.7 The 10.6 2 5.9 60.2

Example 2

Gypsum cement with a surface area of 490 m ² / kg was prepared from gypsum-free cement (from the clinker of conventional Portland cement) with a sw = 0.31 with 0.8% wt. % Na ₂ CO ₃ and 2 wt. lignínsulfonánu. The cement to sand ratio was 1: 3. After preparation, the mortars were left in a saturated water vapor environment until testing. A number of commercial sodium lignosulfonates were used in these experiments, which differed in pH by 10% by weight. solution. The results are shown in Tab. Second

Table 2

Labeling lignosulfonan pH of a 10% lignosulfonan solution % accompanying monosaccharides Compressive strength (MPa) 4 hours 24 hours A 3.1 8 0 4.5 B 3.8 6 0.2 7.6 C 6.4 2 0.1 10.2 D 7.0 2 1.0 18.1 E 7.8 2 10.5 46.3 F 8.1 2 8.9 47.5 G 8.2 2 15.2 48.3 H 8.4 2 9.4 47.5 I 8.8 2 H, 5 50.2 J 10.5 1 11.3 52.3

Example 3

Mortars with the composition of Example 2 were prepared from gypsum-free cement (from the clinker of conventional Portland cement) with a specific surface area of 520 m ² / kg. The lignin sulfonates according to Example 2 were used for the preparation. with a temperature of -6 ° C. The strength results are shown in Tab. Third

Table 3

Lignin sulfonate (MPa) compressive strength

days 1 day 7 days 28 days C 0.5 12.5 30.8 H 11.2 30.2 45.2 I 10.2 25.6 35.8

Example 4

For the preparation of mortar bodies of 4 x 4 x 16 cm, gypsum-free cement having the following composition: 85.75 wt. % clinker of conventional Portland cement, 0.05 wt. grinding additive (dodecylbenzenesulfonic acid alkanolamide, 1.2 wt.% lignosulfonan, 3 wt.% K ₂ CO ₃ , 5 wt.% amorphous SiO ₂ drift, and 5 wt.% kaolin activated at 800 ° C. the granulated clinker was first ground in the presence of a grinding additive to a surface area of 520 m ² / kg and then mixed in. Two types of lignosulfonates according to Example 2 were used, namely type C (low pH solution) and type 1 (high pH) solution).

After 4 hours (at w = 0.31), the lignin sulfonate mortar reached a compressive strength of 3 MPa, while the lignin sulfonate I achieved a compressive strength of 12 MPa.

Example 5

A blend of gypsum-free cement was prepared from Portland cement clinker and blast furnace granulated slag by simultaneous grinding of clinker and slag in the presence of a liquid grinding additive (0.06 wt%) to a specific surface area of 650 m ² / kg. A slurry w = 0.24 was prepared from this mixed cement with the addition of 1 wt. % lignosulfonan and 1 wt. K ₂ CO ₃ . When using lignosulfonan (according to Example 1) C and B, the strengths after 4 hours were 0.2 MPa for lignosulfonan and 2 MPa for lignosulfonan B. Using lignin sulfonate J, the strength after 4 hours was 6 MPa.

Example 6

Of gypsum-free cement (of standard Portland cement clinker) with a specific surface area of 560 m ² / kg with an additive of 0,8% w / w. % of lignosulfonan I and 1.8 wt. Mortar prepared with ₂ CO ₃ sw = 0.28, where crushed corundum of fraction 0-2 mm was used as filler. After 7 days of hydration, the mortar bodies were dried at 105 ° C and then exposed to 600 ° C for 2 hours. A compressive strength of 45 MPa was achieved.

Example 7

Of clinker with a chemical composition of 64.8 wt. % CaO, 23.6 wt. % SiO ₂ , 3.4 wt. % Al ₂ O ₃ , 4.9 wt. % Fe ₂ O ₃ and 1.8 wt. free CaO was prepared gypsum-free cement with a specific surface area of 550 m ² / kg. The clinker was milled in the presence of 0.03 wt. dodecylbenzenesulfonic acid alkanolamide. The ground clinker was dry blended with 3 wt. highly fine SiO ₂ drift. A slurry was prepared from this cement at w = 0.24 free-flowing consistency. The slurry was prepared with 0.85 wt. sodium lignosulfonate (type I according to Example 2); and

1.2 wt. % Na ₂ CO ₃ , 0.1 wt. triethanolamine. Sodium potassium tartrate was used as a retarder in the preparation. The results of the achieved compressive strengths and the start of solidification are shown in Tab. 4th

Table 4 + 0.1% tartrate 0% tartrate

setting time (min) 50 20 Compressive strength after (MPa) (MPa) 2 hrs 9.2 11.2 3 hrs 9.7 15.6 4 hours 14.2 24 hours 59 69.7 28 days 115.0 116.2 60 days 151 156.2

Example 8

Of clinker with a chemical composition of 66.0 wt. % CaO, 18.9 wt. % SiO ₂ , 5.9 wt. % Al ₂ O ₃ , 3.1 wt. % Fe ₂ O ₃ and 1.9 wt. Free CaO was prepared by gypsum-free cement by grinding to a surface area of 630 m ² / kg with the addition of 0.1 wt. ethylene glycol. Before processing, the composition of gypsum-free cement was supplemented with 3 wt. SiO ₂ drift. A slurry of 0.85 wt. % sodium lignosulfonate (type I according to Example 2), 1.0 wt. % K ₂ CO ₃ and 0.1 wt. triethanolamine sodium. After preparation, the slurries were stored in a tempered room at temperatures ranging from -5 to +20 ° C. The results of the measured properties are shown in Tab. 5th

Table 5

Storage temperature (° C) + 20 +5 - 5

beginning solidification 10 11 8 (Min.) compressive strength (MPa) 2 hrs 13.5 14 7.2 3 hrs 14.2 15.5 11 4 hours 15.6 17.2 11.5 24 hours 63.5 48.5 31 28 days 103.5 76 50.4 60 days 160 86.1 64.2 Example 9

Gypsum w = 0.25 with 0.8% w / w additive was prepared from gypsum-free cement (conventional Portland cement clinker ground with 0.04 wt.%, Dodecylbenzenesulfonic acid alkanolamide) having a specific surface area of 490 m ² / kg. % lignosulfonan, 1.4 wt. Na ₂ CO ₃ and 0.05 wt% sodium gluconate. Measured properties of slurries in Tab. 6th

Table 6

compressive strength (MPa) Lignin sulfonate (according to Example 2) setting time (min.) 24 hours 28 days 90 days G 70 45 75 106 H 95 43 85 108 I 70 40 86 101

Example 10

Gypsum w = 0.25 with 0.8% w / w additive was prepared from gypsum-free cement (conventional Portland cement clinker ground with 0.04% w / w dodecylbenzenesulfonic acid alkanolamide) with a specific surface area of 490 m ² / kg. lignínsulfonánu. The results are shown in Tab. 7th

Table 7

Lignin sulphonan (type according to example 2)

B C H I start of solidification 5 min. 5 min. 2 min. 4 min. strength after 15 min. immeasurable 2 MPa 1.8 MPa MPa after 24 hours 6 8 20 25 after 28 days 38 39 45 50 Example 11

Concrete was prepared from gypsum-free cement (conventional Portland cement clinker grinded with 0.03% by weight, dodecylbenzenesulfonic acid alkanolamide) with a specific surface area of 520 m ² / kg. The concrete had a composition of 1 (cement): 2 (burnt flake 2-4 mnt). Additives of 1 wt. lignin sulfonate (type I according to Example 2) and 1.5 wt. Na ₂ CO ₃ .

After preparation, the concrete was dried at 110 ° C and then fired at 800 and 100 ° C respectively. 1200 ° C. After drying at 110 ° C, the concrete reached a strength of 39 MPa, after firing at 800 ° C 17 MPa, at 1200 ° C 14 MPa.

Example 12

A mortar was prepared from gypsum-free cement (a clinker of conventional Portland cement grinded with 0.03 wt% dodecylbenzenesulfonic acid alkanolamide) having a specific surface area of 500 m ² / kg and granulated blast furnace slag Vítkovice (0-4 mm fraction) was used as filler. The mortar was treated at w = 0.33 and a cement to granulated slag ratio of 1: 2 (w / w). As additives the following were dissolved in water: 0.9% by weight, lignin sulfonate type I according to Example 2 and 2% by weight. Na ₂ CO ₃ (calculated on cement weight). The prepared mortar had a spill (according to EN) of 115 mm, a setting time of 55 min. Mortar has reached strength: after 1 day in saturated water vapor at +20 ° C compressive strength 40 MPa, after 2 days (stored 1 day in saturated water vapor and 1 day in water) 47 MPa, after 7 days 55 MPa and after 28 days 64 MPa (stored 1 day in saturated water vapor and during water tests).

Example 13

A dry prefabricated mortar was prepared from the gypsum-free cement of Example 12, comprising: 1 mass, part of gypsum-free cement + 1.5 parts of granulated blast furnace slag (0 to 2 mm fraction) + additives (0.9% by weight of lignin sulphonate type I according to Example 1) + 2% by weight K ₂ CO ₃ (calculated on the weight of the cement) This mortar was treated only by adding water so that the water coefficient corresponded to w = 0.32 (water to cement ratio). start of solidification after 65 minutes, spill according to EN 195 mm The following compressive strengths were achieved (storage for 1 day in saturated water vapor, then in water until test time at +20 ° C): 2 days 47 MPa, 7 days 59 , 28 days 62 MPa, 90 days 80 MPa.

Example 14

The mortar prepared according to Example 13 was used to make bodies with dimensions of 4.4.16 cm. These bodies were stored for 7 days in saturated water vapor at + 20 ° C. After 7 days, the bodies were dried at 105 ° C and then fired at 300, 600 and 800 ° C for 2 hours. The bodies had a compressive strength of 40.1 MPa after firing at 300 ° C, a compressive strength of 35 MPa after firing at 600 ° C, and a compressive strength of 20 MPa after firing at 800 ° C.

Example 15

From the gypsum-free cement according to Example 12, a mixture of 1 mass, part of gypsum-free cement + 2 parts of sand of Ostrožská Nová Ves (fraction 0 to 2 mm) was prepared. The same ingredients as in Example 13 were dissolved in the water as the additives. The prepared mortar with w - 0.32 had a plastic character with a 133 mm spill and had an initial setting time of 65 minutes. Mortar reached compressive strength after 1 day 42 MPa, after two days 48 MPa, after 7 days 56 MPa and after 28 days 63 MPa.

Example 16

Periodically samples were taken from the industrial production of gypsum-free cement (with a specific surface area of 450 to 520 m ² / kg). Mortar (cement: sand granulometry 1: 3, w = 0.31) was prepared from these samples, where the additives were dissolved in water at a concentration of 1% by weight. lignin sulfonate + 2.5 wt.%. Na ₂ CO ₃ (calculated on cement weight). The results are shown in Tab. 8th

Table 8 type of compressive strength after 1 day (MPa) of lignosulfonan (individual periodic sampling of gypsum-free cement)

G 41.2 40.2 43.8 49 43.2 48.4 44.2 H 45.2 46.2 44.5 52.1 41.5 41.2 44.2 C 15.2 16.4 17.6 14.2 16.2 17.3 17.9

Example 17

From industrial gypsum-free cement with a specific surface area of 500 m ² / kg concrete was prepared with sw = 0.31 with the addition of 1 wt. % lignin sulfonate type I (according to Example 2) and 2.8 wt. Na ₂ CO3. The concrete had an initial setting of 30 minutes and reached a compressive strength of 30 MPa after 1 day.

Example 18

For preparing gypsum-free cements, lignosulfonates C, D, H, I in powder form were used as grinding additives. The preparation of these cements was carried out by grinding cement clinker with the addition of 1 wt. of lignosulfonate powder and the product reached a surface area of 500 m ² / kg. The grinding was carried out under the conditions of a one-time or gradual addition of the grinding additive. From these cements, slurries of sw = 0.23 to 0.25 of free-flowing character were prepared with additives of 1.5 wt. Na ₂ CO ₃ . The slurry sw = 0.25 reached the following strength after 1 day of hydration:

Table 9 Lignosulfonan C

D

H

I strength after 1 day

14,8 MPa

22.6

53.2

56.5

Example 19

An industrial gypsum cement with a specific surface area of 500 m ² / kg was prepared with a mortar sw = 0.31 with the addition of 1 wt. ligninsulfonan type I (according to Example 2) and 2.8 pr. weight. Na ₂ CO ₃ . The mortar was stored for 24 hours in saturated water vapor at + 20 ° C and then in water until day 28. It was then stored in a 2 wt. HCl at + 20 ° C. After 6 months of storage in the solution, 2 wt. HCl had a mortar of 10 wt. weight loss.

Example 20

Well workable mortars of sw = 0.27 (cement: standard sand 1: 3) were prepared from industrial BS cement with a specific surface area of 490 m ² / kg with the addition of 1.0 wt. % sodium lignosulfonate (type 1 according to Example 2) and 2.5 wt. Na ₂ CO ₃ . As a further additive, a SiO ₂ drift was used, replacing it in an amount of 4 wt. cement. From these mortars, 4 x 4 x 16 cm bodies were prepared.

These bodies were left in a saturated water vapor environment at 20 ° C for 24 hours, and part of the bodies were then stored in water. The bodies were immersed in a 5.5 wt. solution of Na ₂ SO ₄ and to a solution of 164g NaCl / L 1. The concentration of the solutions was checked periodically and the solutions were kept at the same concentration. Compressive strength tests were carried out at regular intervals up to 520 days after preparation. The results of the aggressive environment on the poppy bodies after 520 days are shown in Tab. 11th

Table 11 method of storage day in saturated water vapor, then in salt solution day in saturated water vapor, 27 days in water, then in salt solution compressive strength (MPa) 520 d solution Na ₂ SO ₄ solution NaCl

105.2

117.5

116.9

116.5

Control experiment, storage for 1 day in saturated water vapor, 27 days in water, compressive strength after 520 days, 118.1 MPa.

Example 21

From an industrial BS cement with a specific surface area of 500 m ² / kg, two mortars I, II sw = 0.31 and 0.27 were prepared with the addition of 1 wt. % lignin sulfonate type I (according to Example 2) and 2.8 wt. % Na ₂ CO ₃ and 2 wt. thermally activated clay (at 600 ° C). Malta I sw = 0.27 further contained 4 wt. SiO ₂ drift. The cement: sand ratio of mortar I was 1: 2 and the setting time was 30 min. These mortars were stored for 24 hours in saturated steam at + 20 ° C and then in water for 28 days. The compressive strengths of both mortars are given in Tab. 10th

Table 10 mortar compressive strength MPa

2 hrs 4 hours 6 hours 24 hours 7 days 28 days I 6.55 13.5 31.4 64.5 83.3 107.1 II - 7.5 9 51.9 65.2 79.6

Industrial usability

The binder according to the invention can be used for the preparation of slurries, mortars and concretes with a low water coefficient containing conventional building aggregates of dense and lightweight or metallurgical slag, for example blast furnace granulated as aggregates.

The binder can also be used for the preparation of refractory materials, for the preparation of materials resistant to the effects of aggressive environment, for materials hardening at low temperatures and for special construction works such as grouting, gunpoints, repairing damaged concrete surfaces and structures, liquid waste substances and the like. The excellent theological properties of this binder make it suitable for use in the preparation of composite materials, for example fiber-reinforced materials, such as alkaline or polypropylene. The binder enables the preparation of building materials (especially concrete) with a low water coefficient, thus preparing materials with high short and long-term strengths and thus achieving, for example, high-quality concrete. High strengths can also be achieved by combining with high-grade SiO ₂ , or by varying the hydrothermal treatment of concrete,

Claims (7)

PATENT CLAIMS A Portland cement ground clinker binder comprising Portland cement clinker having a specific surface area of 450 to 700 m ² / kg and 0.2 to 5 wt. % lignin derivative selected from the group of ligninsulfonan, sulfonated lignin, wherein% wt. %, based on the weight of the clinker, characterized in that the pH of the lignin derivative in the form of 10 wt. of the solution is in the range of 7.5 to 11. Binder according to claim 1, characterized in that the pH of the lignin derivative in the form of 10 wt. of the solution is in the range of 8 to 11. The binder according to claims 1 to 2, further comprising up to 8 wt. alkali metal salts formed by the group of carbonates, bicarbonates, silicates and / or hydroxides, based on the weight of the clinker. The binder according to claims 1-3, further comprising up to 40 wt. latent hydraulic substances, such as granulated blast furnace slag or power ash, based on clinker weight. The binder according to claims 1-4, further comprising up to 20 wt. of high-grade amorphous SiO ₂ , in the form of SiO ₂ drift from metallurgical products, based on clinker weight. The binder according to claims 1 to 5, further comprising up to 10 wt. thermally activated earth at 600 to 900 ° C, with particle size less than 150.10 ^-6 m, such as thermally activated kaolins, kaolin clays, claystones, montmorillonite clays and bentonites, kaolinitic-illite clays, refractory clays and ceramic slurries, based on weight of clinker. The binder according to claims 1 to 6, further comprising solidification retardants of gypsum-free cements such as boric acid, sodium potassium tartrate or derivatives of organic hydroxy acids based on the weight of clinker. End of document