SU1604802A1 - Initial composition for making lightweight concrete - Google Patents

Abstract

The invention relates to the production of concrete mixtures, in particular, to compositions of porous concrete mixtures with air-entraining additives. The aim of the invention is to increase the degree of porisation of the concrete mix, while simultaneously increasing the strength and decreasing the average density of the hardened concrete. Raw mix for the production of lightweight concrete contains, wt.%: Portland cement 17 ... 21

expanded clay aggregate 61 ... 67

wood saponified resin 0.02 ... 0.04

salts formed as waste during the synthesis of dibutyl phthalate (dry product) 0.02 ... 0.16

water the rest. The degree of porosity of the mixture after 20 minutes after heating is 3.4-4.4%, the average density is 940-970 kg / m ³ , the strength is 5.8-6.7 MPa. 3 tab.

Description

The invention relates to the production of concrete mixtures, in particular, to compositions of porous concrete mixtures with air-entraining additives.

The purpose of the invention is to increase the degree of porisation of the concrete mix, while simultaneously increasing the strength and decreasing the average density of hardened concrete.

The mixture contains salts formed as waste during the synthesis of dibutyl phthalate (SDP). SDP is a large-scale production waste and represents an aqueous solution of 26% concentration of the following composition, in wt.%:

Sodium salts of benzosulfonic acid and dibutyl phthalate 20 Soda2

Dibutyl phthalate2

Butanol0.1

Unknown impurities1 9 Water Else SDF does not find a useful application, its disposal contributes to the protection of the environment.

Introduction to porous concrete mixture additionally SDF increases the surface activity of the system at elevated temperature, its water retention

00

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ability, which has a positive effect on elasticity and viscosity at the interfaces. Thus, there is a dynamic fixation of the structure of a porous concrete mixture, the final result of which is an increase in the degree of porisation of the concrete mixture subjected to preliminary disintegration.

The relationships between portland cement, aggregate, water, and air-entraining additive correspond to the actual composition of structural and thermal insulated claydite-concrete of grades 50-75, most used in the manufacture of narzokhnyh walls.

Preparation of porous concrete mixture includes dosing of initial components and mixing in a laboratory forced-action concrete mixer. Use Portland cement PC-DO, brand 500, clay 800 brand clay and ceramsite gravel brand 500 by bulk mass.

After preparation, the stiffness of the concrete mix, its average density and the volume of entrained air are determined by calculation. Then, the porous concrete mixture is subjected to preliminary electrical heating for 4–5 minutes from 18–20 to 58–60 ° C, and its hardness, average density, and volume of entrained air are checked again.

In addition to the main experiments, samples are formed from hot porous concrete mixture 10 minutes after the raaograin — cubes with an edge of 10 cm in preheating to 48–50 ° C in forms. The samples were thermosized in a heat-insulated chamber for 23 hours. 24 hours after production, the first series of samples was tested. The average density of the expanded clay concrete and compressive strength are determined. The second series is tested after 28 days, after removal from the chamber, the samples are held in air-dry conditions, then the compressive strength is determined.

The compositions of concrete mixtures are presented in table. 1, the results of the extensive tests are given in Table. 2 and 3.

EXAMPLE 1 relates to the control composition without additives, examples 2-4 show the known compositions with the addition of LMS, examples 5, 13 show the compositions of the proposed porous concrete mix, additionally. containing SDP in optimal amounts, and examples 14 and 15 - with the content of SDF) beyond the proposed boundaries.

The data obtained (Table 2) indicate that the proposed

Compositions have a higher degree of porisation after preheating concrete mixes. Immediately after warming up, the proposed compositions of porous concrete mixture are lost in

from 2.7-3.8 times less air entrained than limestone, 10 minutes after warming up - 2.2-2.8 times less. After 20 minutes after a break, the known compositions completely lose the entrained air, whereas in the proposed formulations 43-51% of its initial amount is preserved. Increasing the degree of porisation of the proposed concrete with me

5 of that preliminary heating, has a positive effect on the structure and properties of hardened claydite. A visual assessment of the macrostructure from the fracture of the samples indicates that, in known compositions, in contrast to the proposed pores, the entrained air is deformed and has increased dimensions. These samples are characterized by a cluster, pores in the upper zone - near the open surface.

5 with the formation of cavities and voids.

The results of testing the hardened claydite-concrete (Table 3) show that, due to structural violations, the strength of the known

Composition 0 decreases in comparison with the control composition: when tested after 24 hours, by 28%, when fired through. 28 days - by 19% (examples 1 and 3 with the same cement consumption

 nineteen%). Under these conditions, in the proposed formulations (examples 8-10 with a cement consumption of 19%) there is no decrease in strength in comparison with the control composition and there is a noticeable increase in its strength in comparison with the known compositions. This increase: when cement consumption is 17% (examples 2 and 5-7), after 24 hours - 60-64%, after 28 days - 32-36%, while consumption of cement is 19% (examples 3 and 8-10). ) through

24 hours - 43-54%, after 28 days - 30-34%; with cement consumption of 21% (examples 4 and 11-13) after 24 hours - 36-47%, after 28 days - 23-29%.

0

ten

15

1604802

The increase in the degree of porisation of the compositions of the pre-warmed porous concrete mixture subjected to preheating has a positive effect: It is on the average density of the shutter-clay expanded clay concrete. Comparing the compositions of the known and proposed concrete mixes, characterized by the same consumption of air entraining admixture, we find that the average density in all the proposed examples does not exceed a similar indicator in the well-known examples. At the same time, it is 7-10% below the average

density of lightweight aggregate control composition. These data indicate an improvement in the heat-shielding qualities of the claydite-concrete from the proposed porous claydite-concrete mixture exposed to a preliminary rupture. In turn, this contributes to the reduction of energy consumption for heating buildings.

Thus, data analysis

tab. 2 and .3 shows that the use of the proposed formulations provides an increase in the degree of porosity of the be-TOHHOii mixture subjected to preliminary heating, while simultaneously increasing the strength of

5 F

25

thirty

0

five

concrete and reducing its average density.

Formz la invention

Raw mix for the production of lightweight concrete, including Portland cement, expanded clay aggregate, wood saponified resin and water, characterized in that, in order to increase the degree of porisation while increasing the strength of hardened concrete while reducing its average density, it additionally contains salts as a waste in the synthesis of dibuphphthalate in the following ratio KONfflOHeHTOB, wt%:

Portland Cement17-21

Expanded clay .61-67

Wood saponified Salt Resin, forming EU as a waste in the synthesis of dibutyl phthalate (dry product) Water

0.02-0.04

0.02-0.16 Else

Examples

The ratio of components of lightweight aggregate,

May %

Cement

Checklist Famous

Offered

Offered

Beyond

nineteen

17

nineteen

21

17

17

17

nineteen

nineteen

nineteen

21

21

2119

nineteen

Table 1

1040 1005 1000

980

970

960

960

950

950

940

950

940

, 950

1050

101-0

3.9 2.5 2.8 3.0 4.1 4.0 4.0 4., 0 4.0 4.3 4.1 4.3 3.4 3.1 3.4

table 2

Table 3

5.7 4.4 4.7 5.1 5.8 6.0 6.0

6.1 6.3 6.2 6.3 6.7 6.6 5.0 5.5

Claims (1)

5 claims The raw material mixture for the manufacture of lightweight concrete, including Portland cement, expanded clay aggregate, saponified wood resin and water, characterized in that, in order to increase the degree of porosity while increasing the strength of hardened concrete with a decrease in its average density 15, it additionally contains salts formed in the quality of the waste in the synthesis of dnbutipphthalate in the following ratio components, wt.%: E Portland Cement Expanded Clay- 17-21 weight gain 61-67 Woody Ohms flax resin 0.02-0.04 25 Salts Forming— as waste in the synthesis of dibutyl phthalate (dry product) 0.02-0.16 Water Rest Table Examples The ratio of the components of expanded clay mixture, 1 Control 19 64 2 Famous 17 67 3 19 . 64 4 21 61 5 Proposed 17 67 6 17 67 7 17 67 8 19 64 9 19 64 10 Proposed 19 .64 eleven 21 61 12 21 61 thirteen 21 61 14 Beyond 19 . 64 fifteen 19 64 May. % Water FROM TO SDF 17 _r J 15.98 0.02 - 16.97 0,03 - 17.96 0.04. - 15.96 0.02 0.02 15.94 0.02. 0.04 15.90 0.02 0.08 16.94 0,03 0,03 .16.91 0,03 0.06 16.85 0,03 0.12 17.92 0.04 0.04 17.88 0.04 0.08 17.80 0.04 0.16 16,955 0,03 0.015 16.77 0,03 0.20- 7 1604802 8 table 2 Example • Degree of porosity Loss air involved,% ™ * —— - Until After warming up Right away Through Through warming - ~~ - 10 minutes 20 minutes Right away Through Through 10 minutes 20 minutes --- 1 -  ~ ' • m - - 2 9.7 6.4 2.7 34 72 100 3 10.1 6.3 2.0 - 38 80 100 4 10.5 6.3 1.8 .40 ‘ 83 100 5 9.0 8.1 6.2 3.9 10 31 57 6 9.1 8.3 6.6 4.1 9 27 55 7 9.2 8.2 6.6 4.2 eleven 28 54 8 9,4 8.3 6.0 3.8 42 36 60 9 . 9.6 8.6 6.7. 4.0 10 thirty 58 10 9.8 8.8 6.6 4.4 10 33 55 eleven . 9.3 7.9 6.0 3.4 fifteen 36 64 12 9.6 8.4. 6.5 3,7 12 32 61 thirteen 9, -9 8.5 6.5. 3.9 14 34 61 ' 14 9.8 6.4 ' 3.0 35 70 100 fifteen 9.8 6.5 3.6 1.3 32 62 82 Table 3 Examples Properties of expanded clay from a hot mixture Average density, kg / m ³ Strength, MPa After 24 h After 28 days 1 1040 3.9 5.7 2 1005 2,5 4.4 3 1000 . 2,8 4.7 4 980 s oh 5.1 5. ' 970 4.1 5.8 6 96C 4.0 6.0 7 960 • 4.0 - 6.0 8 950 ' 4 -, 0. 6.1 9 950 4.0 6.3 10 940 4.3 6.2 eleven 950 4.1 6.3 12 940 4.3 6.7 thirteen 950 4.4 6.6 14 1050 3,1 5,0 fifteen 1010 3.4 5.5