FR2612176A1 - MIXTURE FOR THE PRODUCTION OF CHEMICALLY STABLE CONCRETE - Google Patents

Abstract

THE INVENTION RELATES TO A MIXTURE FOR OBTAINING CHEMICALLY STABLE CONCRETE. ACCORDING TO THE INVENTION, IT CONTAINS, BY WEIGHT: - SOLUBLE GLASS: 8-18 - FINELY DISPERSE AQUIFERED AQUIFERED VOLCANIC GLASS: 30-40 - MODIFYING ADDITIVE: - SILICON BIOXIDE OF CRYSTALLINE MODIFICATION: 1-6 - ETOU KAOLINITE OF STRUCTURE OF PERLITE: 1-6 - ETOU MELAMINECYANURATE: 0.2-1.0 - AGGREGATE RESISTANT TO ACIDS AND ALKALIS: COMPLEMENT TO 100. THE INVENTION APPLIES IN PARTICULAR TO CONSTRUCTION MATERIALS.

Description

The present invention relates to building materials, and more

  precisely a mixture for obtaining a chemically stable concrete based on water glass. Concretes prepared from the proposed mixture will find application in the production of building and technological constructions operating under attack conditions by highly aggressive liquid or gaseous media in chemical industry enterprises as well as metallurgy of non-ferrous metals. and

of iron and steel industry.

  Currently, there are known mixtures containing water glass, or finely ground quartz sand, of

  perlite and a hardener of the silicic acid salt type

  hydrofluoric fluid for the preparation of mortars, sealants

  or cements for protective protective coatings

  ccrrcsifs. The coatings shown have a low thermodynamic density structure and therefore, a high water absorption, low resistance to water and

  an outfit restricted to the action of aggressive media.

  The curing agent used in these blends has a high toxicity, which creates certain

  difficulties during their manufacture.

  A mixture is known for obtaining a concrete

  stable to the action of an acid (U.R.S.S.

  NI 306093) containing water glass, perlite of fractions less than 0.14 mm and 0.14-5 mm, andesite pellet, the ratio of constituents being as follows (% by weight): - soluble glass (. = 1.34 g / cm3) .................. 15-25 - perlite fraction less than 0.14 mm ......... 10-20 - fractional perlite of 0.14-5 mm ................. 15-25

  - andesite gravel of fraction greater than 5 mm complete

  The concrete prepared from the indicated mixture has a mechanical strength limit of 28.0 to 29.0 MPa and bending of 9.6 to 11.0 MPa. The stability of the concrete mentioned in the action of acids, determined according to the change of weight during the boiling in the acid

  sulfuric acid at 40% for i h 1/2 is 96.3 to 97.2%.

  The specified concrete with high acid resistance and highly porous structure is characterized by low mechanical strength and

low resistance to water.

  It is also known a mixture for obtaining silicobeton (SU, A, 513955), containing, in% by weight: - soluble glass ..................... ...

  ..... 15-25 - crushed granulated slag ....................... 20-30 aggregate ........... ........................ 40-55 - finely ground quartz sand at a specific surface area of 2,000-2,500 cm2 / g ..... DTD : ..................... complement..DTD: to 100.

  The mechanical strength of concrete prepared from

  the indicated mixture reaches 80.0-100 MPa thanks to the introduction

  production of finely ground quartz sand which is an active part of the milk binder: er-glass. However, the concrete prepared from this mixture has a high permeability

to acids.

  A mixture is still known for the preparation of a chemically stable concrete (SU, A, 882965) of the following composition (% by weight): - soluble glass ............... ................ 12-13 - finely ground aggregate .....

  ............... 33-34 - aggregate resistant to acids and alkalis .. complement..DTD: to 100.

  The concrete based on the mixture indicated is characterized by a low level of durable mechanical resistance during a complex action of a mechanical load and an aggressive medium as well as a high permeability to acids and a high absorption of water and a weak

water resistance.

  It has therefore been proposed to improve the mixture to obtain chemically stable concrete by a qualitative and quantitative selection of modifying constituents ensuring the concrete a high level of resistance to the complex action of a mechanical load and a medium aggressive, low permeability to acids and

a high resistance to water.

  The solution consists in providing a mixture for preparing chemically stable concrete containing water glass, finely dispersed aquiferic acidic glass acid, an acid and alkali resistant aggregate, which mixture according to the invention contains of crystalline modification silicon and / or kaolinite of perlite structure and / or melaminecyanurate, the ratio of the constituents being as follows (% by weight): - soluble glass ............. .................... 8-18 volcanic glass acice aquifer finely dispersed ..................... ....

  .......... 30-40 - crystalline modification silicon dioxide ........ DTD: .................... ....... 1-6 etic / or kaclinite this structure of perlite ...... 1-5 and / or melaminecyanurate ................. ...... G, 2-1.0 - acid and alkali resistant acrecat supplement..DTD: at 100.

  The introduction into the mixture of one of the

  modifying additives or their mixture improves significantly

  the physico-mechanical properties of chemical concrete-

  stability, which determine the high efficiency of its use in technological constructions and buildings which, during operation,

  high loads in aggressive environments.

  Indeed, the concrete indicated in comparison with the

  known concrete according to the U.R.S.S.

  N 882965 is characterized by: - an increase of 25 to 45% in the duration of the resistance to the action of the mechanical load and the aggressive medium; a reduction of 60 to 64 of the permeability to acids; - a reduction of 28 to 30% of the water absorption; - an increase of 10 to 15% 9 of the resistance

at the water.

  In order to reduce the permeability to acids of chemically stable concrete, to ensure a high modulus of elasticity and a high level of acid resistance, durable in dry air conditions and under the action of acids, it is advantageous that the mixture has the following composition (% by weight): - soluble glass .......................... 12-15 - volcanic acid glass aquifer finely dispersed obsidian ............ 35-40 - crystalline modified silicon dioxide ........................ 1- 6 - aggregate resistant to acids and alkalis .............................. complement

100.

  In order for the chemically stable concrete to have a high resistance to water, it is preferable that the mixture has the following composition (% by weight): soluble glass ................. ....... 8-12 -volcanic acid aquifer finely dispersed perlite ............ 30-35 -kolinite perlite structure ...... 1-5 -aggregate resistant to acids and alkalis ............................... complement

100.

  For the use of chemically stable concrete in aggressive media of various types, (neutral acids, alkalis), it is desirable that the mixture has the following composition (% by weight): - soluble glass.

  ..................... 15-18 - perlite ........................ ...... 32- 34 - crystalline modification silicon dioxide ........................ DTD: ... 2-4 - kaolinite of structure of perlite ..... 2-4 - aggregate resistant to acids and alkalis ........................... .. DTD: at 100.

  The introduction into the mixture of melamine

  cyanurate at a rate of 0.4 to 0.65c by weight ensures

  chemically stable concrete the highest absorp-

  water and water resistance.

  The proposed mixture for obtaining chemically stable concrete compositions mentioned above

is prepared as follows.

  A mixture of dry constituents is prepared by stirring the acid and alkali resistant aggregate, the finely dispersed aquiferic acidic glass and

  modifying additives such as silicon dioxide -

  of crystalline structure and / or kaclinite of perlite structure. The resulting mixture is stirred with the water-soluble glass, the modified amine-melaminecyanurrate, until a homogeneous mixture is formed for the preparation

chemically stable concrete.

  Quantitative selection of constituents is determined by physico-mechanical characteristics.

  imposed on the chemically stable concrete to obtain.

  According to these requirements which must meet the concrete during its exploitation in different aggressive media, the mixture may contain, in its composition, either one of the modifying additives indicated, or their

  mix with different combinations.

  The mixture thus prepared is placed in forms, mulled and subjected to hydrothermal treatment.

  at a pressure of 0.6 to 1.2 MriPa for 6-10 hours.

  Acid-resistant and alkali-resistant aggregate can be used with quartz sand and gravel.

  granite, quartzite, diabase, andesite.

  As volcanic acidic aquifer glass, it is

  possible to use perlite, obsidian, vitrofir.

  The positive effect is reached after introducing, into the mixture, modifying additives at the following quantity (% by weight): crystalline modification of silicon dioxide .................. .......... 1-6 kaolinite of perlite structure .... 1-5 - melaminecyanurate .............

  0.2-1.0 The introduction of silicon dioxide in the mixture at the indicated amounts promotes the formation of a more organized feldspar structure in hardened concrete. When the content of the silicon dioxide mixture is less than 1% by weight, mordenite, together with the feldspar, is formed, which results in a reduction in the level of the durable resistance. aggressive environments.

  The admission, in the mixture, of the

  more than 6% by weight of silicon, is not rationally

  because it does not change the structure of the

  concrete and plays the role of inert aggregate.

  In the water-pearlite system (obsidian, vitrofir), together with stable feldspar-type minerals, large quantities of free alkali are present. The kaolinite of perlite structure admitted at a rate of 1-5% by weight reacts with the alkali and forms aluminosilicates insoluble in water, the presence of which in the concrete ensures a durable resistance

with water and alkalis.

  The influence of melaminecyanurate on the concrete structure is determined by its hydrophobic effect. When the content of the melaminecyanurate mixture is less than 0.2% by weight, the hydrophobic effect is insignificant, the concrete is characterized by a high water absorption and a limited resistance to water, and its content greater than 1% by weight does not result in

  the improvement of the physico-mechanical properties of concrete.

  The modulus of elasticity as well as the compressive and tensile strength of mixed concrete

  mentioned were determined by the normal techniques.

  The strength coefficient of the proposed concrete is determined as the ratio of the ultimate compressive strength of samples after 36 hours of boiling in the medium, corresponding to the ultimate strength of similar samples stored under dry air conditions. The level of durable strength of concrete in an appropriate aggressive medium characterizes the ability

  from it to a durable resistance to loads.

  The level of the durable mechanical strength of concrete is determined for all compositions by the

unique technique below.

  The strength of the concrete sample in a press is determined during a short-term increase in charge until it is destroyed (eg R = 100 MPa), then the sample is compressed to a nearby charge of the limit (for example, '= 0.95 R, ie, R = 95 MPa) and the time is recorded from the time of loading the sample until it is destroyed. At the upper end, the level of charge for new samples is annealed at 6 = 0.90 R, o = 0.85 R, 0 = 0.80 R, etc., the time of existence of the concrete is then recorded. under load for each level of load. A curve characterizing the time of existence of the concrete under this or that load is drawn

  using the data obtained in a coordinate system

  "loading-time level".

  According to this curve, it is determined, by

  polation, the level of the charge compared to the one that is destructive, that the sample can undergo at any time. The level to be determined is the one

  the durable resistance of concrete.

  For the determination of the level of the durable resistance of the concrete to the aggressive media, the samples of concrete undergo before a boiling during 36 hours and a maintenance in aggressive media

  appropriate until saturation limit.

  Maintaining samples under a load, as described above, is also performed in

26121? 6

  conditions of continuous action of aggressive media.

  The following are concrete examples of how to obtain

  chemically stable concrete of different compositions.

EXAMPLE 1

  A mixture of dry constituents is prepared by mixing 920 kg of obsidian, 460 kg of quartz sand, 506 kg of granite gravel, and 138 kg of crystalline silicon dioxide. We

  mix the resulting mixture with 276 kg of water glass.

  The mixture for the preparation of chemical concrete-

  Stably stable to the following composition (% by weight): - soluble glass .......

  ............... 12 - obsidian ............................ 40 - Dioxide crystalline modification silicon ............. 6 oravillon .......... DTD: .................. 22 ..DTD: sand ................................ 20.

  The mixture is placed in forms and subjected to a hydrothermal treatment at a pressure of

0.6 MPa for 10 hours.

  The concrete obtained in the form of cubic samples undergoes physicomechanical tests, the results of which are

are given on the board.

EXAMPLE 2

  A mixture of dry constituents is prepared by mixing 805 kg of obsidian, 575 kg of quartz sand, 552 kg of granite chippings and 23 kg of crystalline silicon dioxide. The resulting mixture is stirred with water glass taken from

  345 kg, until a homogeneous mixture is formed.

  The mixture prepared to obtain the chemically stable concrete has the following composition (% by weight): - soluble glass ......................... 15 - obsidian ............................. 35 - crystalline modified silicon dioxide .......... ................. 1 - chippings .........

  .............. 24..DTD: - sand ............................ 25 .

  The mixture is put into forms and subjected to hydrothermal treatment at the pressure of 0.8 MPa for 6 hours. Concrete samples, obtained in the form of cubes, undergo physico-mechanical tests of which

  the results are summarized in the table.

EXAMPLE 3

  A mixture of dry constituents is prepared by stirring 805 kc oerlite, 506 kg quartz sand, 690 kg quartzlee grit, 115 kg kaolinite this perlite structure. The mixture obtained is stirred with water glass taken at the rate of 184 kc, up to

  obtaining a homogeneous mixture.

  The pre-prepared mixture for the preservation of chemically stable concrete has the following composition (% by weight): - soluble glass ....................... 8 - perlite ............................. 35 - kaclinite this structure of perlite ... 5 - gravel ........ ................... 30

  - sand ............................... 22.

  The mixture is placed in forms and subjected to a hydrothermal treatment at the pressure of

0.9 M: Pa for 10 hours.

  Concrete in the form of cubes undergoes physico-mechanical tests, the results of which are summarized in

board.

EXAMPLE 4

  A mixture of dry constituents is prepared by stirring 690 kg of perlite, 575 kg of quartz sand, 736 kg of quartzite grit and 23 kg of kaolinite of perlite structure. The mixture obtained is stirred with water glass taken at a rate of 276 kg, until the

formation of a homogeneous mixture.

  The mixture Drepared to obtain chemically stable concrete with the following composition (by weight): - soluble glass ..................... 12 - perlite ... ........................ 30 - kaolinite of perlite structure .. 1 - chippings .............. ........... 32

  - sand ............................. 25.

  The mixture is placed in a form and subjected to hydrothermal treatment at atmospheric pressure.

0.8 MPa for 8 hours.

  The concrete obtained in the form of cubes undergoes physico-mechanical tests, the results of which are given

to the blackboard.

EXAMPLE 5

  A dry mixture is prepared by stirring 782 kg of perlite, 460 kg of quartz sand, 529 kg of diabasic grit, 92 kg of crystalline silicon dioxide, 92 kg of stria kaolinite. perlite. The resulting mixture is stirred with the water glass

  from 345 kg until a homogeneous mixture is obtained.

  The mixture prepared to obtain chemically stable concrete has the following composition (% by weight): - soluble glass ..................... 15 - perlite .. ......................... 34 - crystalline modified silicon dioxide ................. ....... 4 - kaolinite of perlite structure .. 4 - chippings .......................... 23 - sand.

  ............................. The mixture is dispensed into shapes and subjected to hydrothermal treatment at .DTD pressure. : 1.0 MPa for 6 hours.

  The concrete obtained in the form of cubes undergoes physico-mechanical tests, the results of which are

presented on the board.

EXAMPLE 6

  A mixture of dry constituents is prepared by stirring 736 kg of perlite, 460 kg of quartz sand, 598 kg of diabasic grit, 46 kg of crystalline silicon dioxide, 46 kg of kaolinite of perlite structure. The mixture prepared is mixed with 417 kg of water-glass until a

homogeneous mixture.

  The mixture prepared to obtain chemically stable concrete has the following composition (% by weight): - soluble glass ...................... 18 - perlite. ........................... 32 - crystalline modification silicon dioxide ............... ......... 2 - kaolinry of perlite structure. 2 - chippings. 26

  - sand ............................. 20.

  0- place the melarze cars a form and subjected to treatment hvcrotherqua the pressure of 1.2 MPa

during 6 hours.

  Concrete samples in the form of cubes undergo physico-mechanical tests, the results of which

are summarized in the table.

EXAMPLE 7

  A mixture of dry constituents is prepared by stirring 920 kg of perlite, 414 kg of quartz sand, 754 kg of granite chippings. We mix the mixture

  prepared with 184 kg of water-soluble glass and 23 kg of melamine-

  cyanurate until a homogeneous mixture is obtained.

  The mixture prepared to obtain chemically stable concrete has the following composition (% by weight): - soluble glass ....................... 8 - perlite ............................. 40 - melaminecyanurate ..........

  ....... 1 - chippings .......................... 33..DTD: sand ........ ...................... 18.

2 6 1 2 1? 6

  The mixture is placed in a form and subjected to hydrothermal treatment at atmospheric pressure.

0.8 MPa for 6 hours.

  The concrete obtained undergoes the physical tests

  the results are given in the table.

EXAMPLE 8

  A mixture of dry constituents is prepared by stirring 690 kg of perlite, 621 kg of quartz sand, 570.4 kg of granite chippings. The resulting mixture is stirred with 414 kg of water-soluble glass and 4.6 kg of

  melaminecyanurate until a homogeneous mixture is obtained.

  The mixture prepared to obtain chemically stable concrete has the following composition, (% by weight): - soluble glass .......................

  18 - perlite ................................ 30 melaminecyanurate ...... DTD: ..... .......... 0.2 chippings ............................ 24.8..DTD: sand ................................. 27.

  The mixture is placed in a form and subjected to hydrothermal treatment at a pressure of

0.6 MPa for 10 hours.

  Concrete samples in the form of cubes undergo physico-mechanical tests, the results of which

are shown on the board.

EXAMPLE 9

  A mixture of dry constituents is prepared by stirring 920 kg of obsidian, 469 kg of quartz sand, 621 kg of diabasic grit, 92 kg of crystalline modified silicon dioxide. The mixture obtained is stirred with 184 kg of waterglass and 13.8 kg of melaminecyanurate until a homogeneous mixture is obtained. The mixture prepared to obtain chemically stable concrete has the following composition (% by weight): - soluble glass ....................... 8 - obsidian ..............

  ............ 40 - crystalline modification silicon dioxide ......... DTD: ................ 4 melaninecyanurate. .................. 0.4 chippings ........................... 27 sand ............................. DTD: .. 20.4. The mixture is placed in a form and subjected to hydrothermal treatment at a pressure of DTD 0.7 MPa for 9 hours.

  Concrete samples in the form of cubes undergo physico-mechanical tests, the results of which

are given on the board.

EXAMPLE 10

  A mixture of dry constituents is prepared by stirring 690C kg of obsidian, 529 kg of quartz sand, 588.8 kg of diabasic sponge, 46 kg of silica gel. this crystalline modification. We mix the mixture

  obtained with 414 kg of water-soluble glass and 9.2 kg of melamine-

  cysnurate until it obtains a homogeneous mixture.

  The mixture prepared to obtain chemical concrete-

  Stably stable to the following composition (- in poios): - soluble glass ......

  .............. 18 - cbsidiane ......................... 30 - silicon dioxide or crystalline modification ........................ 2 melaminecyanurate 0.4 - chippings ................... ...... 25.6..DTD: sand .............................. 23.

  The mixture is placed in a form and subjected to hydrothermal treatment at a pressure of

0.9 MPa for 7 hours.

  Concrete samples in the form of cubes undergo physico-mechanical tests, the results of which

are shown on the board.

EXAMPLE 11l

  A mixture of dry constituents is prepared by stirring 920 kg of perlite, 414 kg of quartz sand, 584.2 kg of quartzite grit, 92 kg of

2 6 1 2 1? 6

  crystalline modified silicon, 92 kg of kaolinite structure of perlite. The mixture obtained is stirred with 184 kg of waterglass and 13.8 kg of melaminecyanurate until a homogeneous mixture is obtained. The mixture prepared to obtain chemically stable concrete has the following composition (% by weight): - soluble glass ....................... 8 perlite ... .......................... 40 - crystalline modified silicon dioxide ................ ......... 4 - melaminecyanurate ...

  .............. 0.6 - kaolinite of perlite structure ... 4 chippings ... DTD: ................. ....... 24.4..DTD: sand ............................... 18.

  The mixture is placed in a form and subjected to hydrothermal treatment at a pressure of

1.0 MPa for 7 hours.

  The concrete samples, in the form of cubes, undergo physico-mechanical tests whose results

are shown on the board.

EXAMPLE 12

  A mixture of dry constituents is prepared by stirring 690 kg of perlite, 478.4 kg of quartz sand, 616.4 kg of quartzite grit, 46 kg of crystalline silicon dioxide, 46 kg of kaolinite of perlite structure. The resulting mixture is stirred with water glass taken at a rate of 414 kg and 9.2 kg of melaminecyanurate until a mixture is obtained.

homogeneous.

  The mixture prepared to obtain chemical concrete-

  Stably stable to the following composition (% by weight): - soluble glass ......

  ................. 18 - perlite .............................. 30 - crystalline modification silicon dioxide ........................... 2 melaminecyanurate ............ ...... 0,4 - kaolinite of perlite structure .. 2 - chippings .......................... 26,8 sand .............. DTD: ................ 20.8 The mixture is placed in a form and subjected to a hydrothermic treatment at a pressure of 0.8 MPa for 8 hours. Concrete samples in the form of cubes undergo physico-mechanical tests, of which DTD: results are presented in the table.

BOARD

  N Resistance, MPa: Strength index of compres-. trac- in 20% absorption exe- sion water H2S04 water,% ples

1: 2: 3: 4: 5: 6

1i 100 8.7 0.86 0.94 5.0

2,100 8.5 0.86 0.94 4.9

3,130 11.8 0.92 0.95 4.9

4,135 12.1 0.94 0.96 4.8

130 11.8 0.92 0.95 4.9

6,135 12.1 0.94 0.96 4.8

7,135 12.1 0.94 0.95 3.3

8,140 12.3 0.95 0.96 3.4

9,130 10.6 0.94 0.95 3.3

130 8.3 0.95 0.96 3.4

it 135 12.1 0.94 0.95 3.3

12,140 12.3 0.95 0.96 3.4

12176

  TABLE (continued) penetra- modulus level of durable resistance of elas- tensile concrete acid. ticity, air in water 20% 5% mm MPa: H2SO4 NaOH 1 7: 8: 9: 10 il: 11: 12

1 15 55000 0.75 0.65 0.50 0.20

2 15 54000 0.75 0.65 0.55 0.20

3 33 54000 0.75 0.72 0.70 0.36

4 35 56000 0.75 0.75 0.72 0.38

14 54000 0.80 0.72 0.70 0.37

6 15 56000 0.80 0.75 0.72 0.38

7 24 55000 0.75 0.86 0.72 0.20

8 2 56000 0.75 0.65 0.71 0.20

9 14 54000 0.80 0.86 0.72 0i20

15 55000 0.80 0.85 0.71 0.20

he 14 55000 0.80 0.90 0.78 0.38

12 15 56000 0.80 0.90 0.77 0.38

Claims (5)

R E V E N D I C A T I 0 N S   1.- Mixture for obtaining chemical concrete-   stable composition containing water-soluble glass, a finely dispersed aquifer-acidic volcanic glass, an acid and alkali-resistant aggregate, characterized in that the mixture contains a modifying additive, especially crystalline modified silicon dioxide and / or kaolinite of structure of perlite and / or melaminecyanurate, at a ratio depending on the constituents (% by mass): - soluble glass ...........   ....... 8-18 - finely dispersed aquiferic acidic volcanic glass .......... CLMF: ...... 30-40 modifying additive: - crystalline modification silicon dioxide. ..................... 1-6 - and / or kaolinite of perlite structure ................. .......... 1-5 - and / or melaminecyanurate ........... 0,2-1,0 - aggregate resistant to acids and alkalis ..................... CLMF: .. complement..CLMF: to 100.   2. Mixture according to claim 1, characterized in that it contains obsidian as finely dispersed aquifer acidic glass and has the following composition (% by weight): - soluble glass ....... .........   .......... 12-15 - obsidian ......................... 35-40 - crystalline modified silicon dioxide ........................ 1-6 - acid and alkali resistant aggregate ............... ............. supplement..CLMF: to 100.   3. A mixture according to claim 1, characterized in that it contains perlite as finely dispersed aquifer volcanic glass and has the following composition (% by weight): - soluble glass ......... ............ 812 - perlite ........................... 30-35 - structure kaolinite perlite. 1-5 - aggregate resistant to acids and alkalis ................ ..... addition..CLMF: to 100.   4. Mixture according to claim 1, characterized ecn that it has the following composition (c by weight): - soluble glass ...................... 15-18 - perlite ............................ 32-34 - crystalline modified silicon dioxide ....... ................. 2-4 - sr kaolinite this perlite ..... 2-4 - acid and alkali resistant aggregate ........ .   ................ complement..CLMF: to 100.   5.- ', élance selor any of the 2,3 o- revenoicaticrs, characterized in that it contains melaminecyanurate taken at a rate of 0, 4 to 0.6% of the mass duoit mixture.