RU2553818C2 - Raw mixture for making ash and alkali concrete - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention refers to construction materials industry and can be used in making building structures and units. The raw mixture for making ash and alkali concrete containing a binding agent consisting of liquid glass with a silica ratio of n=0.8-1.2 and a density of ρ=1.37-1.39 g/cm³ produced of industrial ferrosilicone waste from Bratsk Ferroalloy Plant that is silica fume having a bulk density of ρ_b=270-290 kg/m³ and a percentage of other impurities of 1.1-3.8%, and flue ash II field by Kansk-Achinsk brown coal combustion at Bratsk Central Heating and Power Plant TETs-7 at a bulk density of ρ_b=980-1,050 kg/m³ and a sieve No. 008 residue of 7.3-9.8%, and a filling agent that is Bratsk Aggregates Plant waste, rejected dunstone chips having a bulk density of ρ_b=1,560-1,690 kg/m³, a crushability strength of 9.8-12.6%, in the following fraction grains, wt %: fr. 5 mm 45.0, fr. 2.5 mm 21.3, fr. 1.25 mm 10.7, fr. 0.63 mm 7.6, fr. 0.315 mm 8.7, fr. 0.14 mm 6,7 and containing 0-15% of clay impurities in the following proportions of the raw mixture components, wt: above flue ash II field 21.1-22.7, above liquid glass 9.2-15.6, above rejected dunstone chips 63.3-68.1.

EFFECT: higher strength.

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Description

The invention relates to the building materials industry and can be used for the manufacture of structures and concrete products based on aggregate from substandard raw materials and allows for the efficient use of large-tonnage industrial wastes.

Concrete mixtures are known, including aggregate - screening from crushing of diabase and a binder, consisting of fly ash of the first field, from ground dump ash and slag mixture and liquid glass, made from large-tonnage waste from the production of ferrosilicon of the Bratsk ferroalloy plant - silica fume, with silicate module n = 1 and density ρ = 1.30-1.45 g / cm ³ [Patent RU No. 2470900 C1, C04B 40/00, 28/26, 28/08, 111/23, 12/27/2012, p.7].

The disadvantages of concrete based on this concrete mixture are the low strength indicators of concrete, the multicomponent composition, the need to grind the ash and slag mixture.

The closest analogue to the described invention is a raw material mixture, including aggregate and binder, consisting of fly ash I field with ρ _us = 800-850 kg / m ³ and the residue on sieve No. 008 - 6.7% and liquid glass made from bulk waste from the production of ferrosilicon of the Bratsk Ferroalloy Plant - silica fume with ρ _us = 215-220 kg / m ³ and containing highly dispersed crystalline impurities in the form of carborundum and graphite in the amount of 8-10%, with silicate module n = 1-1.5 and density ρ = 1.33-1.34 g / cm ³ , and as a filler use screening from dr pouring diabase blocks onto crushed stone with ρ _us = 1590 kg / m ³ and a moisture content of 1-2% [Patent RU No. 2374201 C1, C04B 28/26, 111/20, November 27, 2009, p.4].

The disadvantage of the described raw mix is the low strength characteristics of concrete made from this raw mix, and the use of pure (unalloyed) aggregate as raw material, which limits the use of the resulting concrete.

The problem solved by the invention is to improve the quality of the raw mix, expanding the range of raw materials.

The technical result is an increase in the strength characteristics of concrete. The specified technical result in the implementation of the invention is achieved by the fact that the raw mixture for the preparation of ash-and-concrete concrete includes a filler and a binder, consisting of an aluminosilicate component and an alkaline component - liquid glass with silicate module n = 0.8-1.2 and density ρ = 1.37 -1.39 g / cm, made from industrial waste from the production of ferrosilicon of the Bratsk Ferroalloy Plant - silica fume, characterized by a bulk density ρ _n = 270-290 kg / m ³ and losses after calcination of 1.1-3.8%; as an aluminosilicate component of the binder, fly ash of the second field is used, which is formed by burning brown Kansko-Achinsk coal at TPP-7 in Bratsk and characterized by a bulk density of ρ _n = 980-1050 kg / m ³ and a residue on sieve No. 008 - 7, 3-9.8%, and technogenic waste from the Bratsk nonmetallic building materials plant is used as a filler - screening from crushing of diabase, characterized by bulk density ρ _n = 1560-1690 kg / m ³ , crushing strength 9.8-12.6% , with the ratio of grains of fractions, wt.%:

fr. 5 mm  45.0 fr. 2.5 mm  21.3 fr. 1.25 mm  10.7 fr. 0.63 mm  7.6 fr. 0.315 mm  8.7 fr. 0.14 mm  6.7

and containing 0-15% clay impurities, in the following ratio of components of the raw material mixture, wt.%:

Indicated fly ash II field  21.1-22.7 Specified Liquid Glass  9.2-15.6 Indicated screening from crushing diabase  63.3-68.1

The raw material mixture for the preparation of concrete was prepared as follows.

Fly ash of the II field, formed by burning brown Kansko-Achinsk coal at TPP-7 in Bratsk and characterized by a true density ρ _and = 2780 kg / m ³ , humidity 0.33% and losses after calcination 2.16%, was mixed with aggregate - screening from crushing of diabase, characterized by a true density ρ _and = 2940 kg / m ³ and a particle size modulus of 4.2. The ratio between fly ash and aggregate was “Ash-upos II field: Screening from crushing diabase” = 1: 3. The properties of the materials used are presented in tables 1-4.

After mixing, silica fume, characterized by a true density ρ _and = 2360 kg / m ³ and a moisture content of 0.8%, with a silicate module n = 0.8-1.2 and a density ρ = 1.37- was added to the mixture of dry components. 1.39 g / cm ³ . The mixture was mixed in a forced-action concrete mixer for 2-3 minutes. 4 × 4 × 16 cm beam samples were molded at the laboratory vibratory platform. Samples were solidified in a TBO chamber at a temperature of 80 ± 5 ° C according to the 1 + 2 + 4 + 2 hours regime. After this, the steamed samples were tested for strength. Similarly, concrete based on raw mixes of other compositions was prepared and tested. The results are presented in table 5.

Table 1 Physical characteristics of fly ash II field Bulk density, kg / m ³ True density, kg / m ³ Humidity% The residue on sieve No. 008,% Loss after calcination,% 980-1050 2780 0.33 7.3-9.8 2.16

table 2 The chemical composition of fly ash II field The content of oxides, wt.% SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ Cao Na ₂ O K ₂ O SO ₃ MgO 50,5 8.6 8.4 20.5 0.1 0.6 1,5 1.7

Table 3 Screening properties from crushing diabase Bulk density, kg / m ³ True density, kg / m ³ The content of clay impurities,% Crushing strength,% The modulus of fineness (MKR) 1560-1690 2940 0-15 9.8-12.6 4.2 Table 4 Grain screening from crushing diabase Sieve residues,% Sieve hole sizes, mm 5,0 2,5 1.25 0.63 0.315 0.14 private 45.0 21.3 10.7 7.6 8.7 6.7 full 45.0 66.3 77 84.6 93.3 one hundred

Table 5 Test results No. p / p The composition of the mixture, wt.% Material Properties The strength of the samples after TVO, MPa Astringent Aggregate Silicon silica water glass Silica fume Fly ash II field Screening from crushing diabase Fly ash II field Silicon silica water glass Screening from crushing diabase Silicate module Density, g / cm ³ Bulk density, kg / m ³ Loss after calcination,% Bulk density, kg / m The residue on sieve No. 008,% Bulk density, kg / m ³ Crushing strength,% The content of clay impurities,% when bending under compression one 22.7 9.2 68.1 0.8 1.37 290 3.8 1030 9.1 1600 10.6 0 7.24 37.1 2 22.5 10.0 67.5 0.9 1.39 275 2.9 1040 9,4 1660 11.8 one 7.38 38,4 3 22 2 11,2 66.6 1,1 1.38 280 1.4 980 7.3 1560 9.8 3 8.05 41.1 four 22.0 12.0 66.0 1,0 1.38 270 1,1 1010 8.4 1640 12,2 5 8.30 44.7 5 21.7 13,2 65.1 1,1 1.37 285 1.7 990 7.7 1680 11.0 7 8.38 40.6 6 21.5 14.0 64.5 1,2 1.39 280 2.1 1050 9.8 1580 10,2 10 8.56 39.0 7 21.3 14.8 63.9 0.9 1.38 275 2,5 1020 8.7 1690 12.6 12 8.68 38,4 8 21.1 15.6 63.3 0.8 1.39 290 3.4 1000 8.0 1620 11,4 fifteen 7.57 38.1

Analysis of the obtained data shows that concrete based on the proposed raw material mixture is characterized by sufficiently high strength indicators exceeding the strength characteristics of concrete according to the prototype. At the same time, the proposed raw material mixture contains aggregate clogged with clay impurities, in contrast to the analogue using pure (impurity) aggregate. As you know, natural, and especially technogenic raw materials, always contain extraneous inclusions and impurities, the amount of which in the aggregate is limited by GOST to 5%. However, as can be seen from the data presented, the increased content of clay impurities does not adversely affect the strength characteristics of concrete. On the contrary, the absolute strength indices of concrete, in which the aggregate containing clay impurities is used, exceed the indices of the control pure composition. This is due to the fact that clay minerals actively interact with water glass to form low-basic calcium silicates and zeolite-like minerals with high strength. Clay particles, activated by alkali of water glass and partially connected by products of hydration of ash particles, evenly distributed in their mass, fill the voids in the concrete matrix, strengthening its structure. Thus, the proposed raw material mixture allows the use of substandard aggregate and expand the range of raw materials.

Claims (1)

Raw mix for the preparation of ash-and-lime concrete, including aggregate and binder, characterized in that the binder consists of an aluminosilicate component and an alkaline component - liquid glass with silicate module n = 0.8-1.2 and density ρ = 1.37-1.39 g / cm ³ made from industrial waste from the production of ferrosilicon of the Bratsk Ferroalloy Plant - silica fume, characterized by a bulk density ρ _n = 270-290 kg / m ³ and losses after calcination of 1.1-3.8%; as an aluminosilicate component of the binder, fly ash of the second field is used, which is formed by burning brown Kansko-Achinsk coal at TPP-7 in Bratsk and characterized by a bulk density of ρ _n = 980-1050 kg / m ³ and a residue on sieve No. 008 - 7, 3-9.8%, and technogenic waste from the Bratsk nonmetallic building materials plant is used as a filler - screening from crushing of diabase, characterized by bulk density ρ _n = 1560-1690 kg / m ³ , crushing strength 9.8-12.6% , with the ratio of grains of fractions, wt.%:
fr. 5 mm 45.0 fr. 2.5 mm 21.3 fr. 1.25 mm 10.7 fr. 0.63 mm 7.6 fr. 0.315 mm 8.7 fr. 0.14 mm 6.7
and containing 0-15% clay impurities, in the following ratio of components of the raw material mixture, wt.%:
Indicated fly ash II field 21.1-22.7 Specified Liquid Glass 9.2-15.6 Indicated screening from crushing diabase 63.3-68.1