SU1430384A1 - Raw material mixture for producing cellular concrete - Google Patents

Abstract

The invention relates to the building materials industry and can be used for the manufacture of thermal insulation materials and structural support elements for industrial, civilian, agricultural, and other types of construction. The purpose of the invention is to increase the strength of products. Raw mix for the manufacture of cellular concrete contains, wt.%: Portland cement 10-15; ash ash 20-25; aluminum powder 0,085- 0,090; metallurgical waste 3-8; waste of metallurgical production of ferrosilicon 31-36; water - § rest. Strength of cellular concrete 7,55-8,60 MPa. 2 tab. (L

Description

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The invention relates to industrial construction materials and can be used for the manufacture of thermal insulation materials and structural support elements for industrial, housing, civil, agricultural, energy, transport and other types of construction.

The purpose of the invention is to increase the strength of products.

The process of preparing a cell concrete mix is traditional with the use of vibrotechnology, consisting in preliminary mixing in a self-propelled mixing unit in a binder and finely dispersed siliceous ass with water. After pre-mixing of the components, BAC (water-aluminum slurry) is added to the mixture; additional mixing is performed until the gasifier is distributed evenly in it. The finished mixture is poured into a mold in which mass swelling occurs.

Methlshlurgic lime waste is produced during the burning of carbonate rocks in rotary kilns. The chemical composition of metallurgical lime, wt.%:, Si02l, 45; , 58; CaO 56.07; MgO 9.9; N / 0 8.5; CO 19.7; ppt 22.3; respectively: carbonates 51.7; , 5i MgOc6 other 3.6.

The oxides contained in the metallurgical lime waste are in a chemically active form and are able to interact with the clinker minerals of portland cement, forming hydrosilicates and calcium hydroaluminates. When forming the cement stone structure, an important role is played by the high specific surface of this waste (reaching 5000 and more), contributing to the intensive growth of the plastic strength of the molded raw material. In addition, due to the high degree of dispersion, metallurgical wastes do not require additional fracture, which significantly reduces energy production costs.

The strength of materials of conglomerate structure is influenced by various aspects of the formation of the structure of cement stone. The strength of the conglomerate depends on the cohesion of the cement0

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of the filler and the adhesion of the cement to the surface of the filler. In this connection, the introduction of an additional dust product into the mixture (waste products from the metallurgical production of ferrosilicon) creates optimal conditions for the synthesis of metastable products, ensuring the formation of stable minerals during further hydrothermal processing.

The dust product is a waste of metallurgical production of ferrosilicon. In chemical composition, it is similar to finely ground quartz, differing mainly in the presence of alkali metal oxides and not exceeding 1.8%. The size of particles is 1.0 microns, the structure is loose, the surface is in the smallest numerous crusts, the bulk density is p ZOOkg / m, specific surface area S 10000 - 12000 (according to the goods).

As a result of the introduction of a composite mixture of a dust product of waste from the production of ferrosilicon, optimal conditions are created for the formation of the structure of cellular concrete. The macro and microstructure of products from such concrete is made more uniform and fine-grained (a cellular structure with honeycomb porous). This is facilitated by ferrosilicon, which, reacting with an alkaline medium, forms hydrogen, and the silica liberated during the reaction forms with calcium hydrate an additional amount of calcium hydrosilicate. The calcium hydrosilicates formed strengthen the walls of the micropores, thereby increasing the strength of cellular concrete.

Calcium hydrosilicates play an important role in the formation of the performance properties of autoclaved materials, therefore one of the most important conditions for the directed structuring of cement stone is their prevailing presence in the neoplasms.

. Physicochemical studies have confirmed the presence of an excess amount of alkalis (+ + CaO) in the mixture, providing an increase in the pH of the mixture and facilitating the intensification of hydration and hydrolysis processes.

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in connection with this, the time of the protec- tion is accelerated; ; ani reaction:

2Al + 3Ca (OH), + 6H20 3CaO-Al20j-6HjO + + ЗН -i t

In this case, the gasifier is used more efficiently, since a significant part of it manages to react before the mixture begins to set. The rate of growth of the plastic strength of the molded clay has a positive effect on the introduction of an active additive into the mixture - metallurgical wastes, which in this case play the role of a catalyst (a kind of seed).

A perfect porous structure is created in the articles, which is characterized by a fairly high uniformity of pore distribution in concrete (PORPB). In addition, low-base calcium hydrosilicates (such as hydrogarnet) formed during the hydrothermal process have greater strength compared to hydroaluminates and calcium hydroferrites. This circumstance explains the improvement of the mechanical strength of products from the proposed raw mix by 16–22% in comparison with the known.

In case of production of equal strength concrete, consumption per hectare is reduced by 25-50%. In addition, the use of the proposed composition of the raw mix allows you to dispose of large-tonnage waste industry, to obtain a significant economic effect and environmental.

Example. In order to obtain raw material mixtures, materials were used: in fine — Portland cement of the brand 400 Amvrosievsky cement combination meeting the requirements of GOST 10178-76; the silica component of the ash of the State Unitary Enterprise of the Kurakhovskaya State District Power Plant with a total density of 750-850 kg / m, ppt 4.8 - 7.2%, satisfying the requirements of GOST 25818-83; active additive - waste of metallurgical lime of the Shchtsanovsky metallurgical plant, formed in the process of burning of carbonate rocks; dust product - a waste of metallurgical production of ferro-silicon silicate of the Stakhanov ferroalloy plant; bulk density is about 300 kg / m, specific surface according to Commodity S 10000-12000, particle size 1.0 micron, structure

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loose, surface in the smallest numerous sinks; solid phase of red mud (dumping bauxite processing product 1), S 5000 - 6000 ppt 5.6%; quartz sand of the Krasnolimansk pit with a net density of f 1450 kg / m, КР О 9-1.1, satisfying the requirements of GOST 8736-77; aluminum powder brand PAP-2, satisfying the requirements of GOST 5494-79; drinking water that meets the requirements of GOST 23732-79.

Raw mixes were prepared with different content of ingredients in accordance with the requirements of CH 483-76. The components of the cheeto-concrete mixture were metered and loaded into a 30-liter laboratory concrete mixer. After preparation of the cellular mass from the resulting mixtures, concrete samples of 10x10x10 cm were formed.

The composition of the proposed and known concrete mixtures are given in table. one.

After swelling and cutting of the hump, the samples were subjected to autoclave treatment according to the following mode: 2.5 + 8 + + 6 h (at 0.8 MPa).

Then the samples were disassembled and tested on GOST 10180- 78 and GOST 25820-83.

Physical and technological properties of samples of concrete mixes are given in table. 2

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From the table. 2. It follows from the data that the use of metallurgical lime as an active additive and an additional dust product (waste of metallurgical production of ferrosilicon) in the proposed raw mix, as compared to the known, allows to increase the strength of concrete 1.37-1.62 times, and equal strength concrete consumption per heel is reduced by 25-50%. In addition, the uniformity index of the distribution of pores in concrete (PORPB) increases from 0.85 to 0.95, and the coefficient of constructive quality (KKK.K.) Increases by 1.5-1.6 times.

Claims (1)

Invention Formula Raw mix for making cellular concrete, including cement, silica filled 51430384 Tel, aluminum powder, an additive and water, characterized in that, in order to increase strength, it contains ash of a hydraulic ash removal as a silica component, as an additive - metallurgical lime waste and additionally a waste of metallurgical production of ferrosilicon at the following ratio of components, wt.%: Portland cement Hydrolay ash Ash Aluminum powder Metallurgical lime waste Metallurgical production of ferrosilicon Water Water Sssta " Sod "11Ш1И1 components of walls, kg / m" s.Х Cemt M 400 IfiieCTli rop) . Hi 20,0 56 575 P, 10.0 70 TVGo §: §- k 9036 Т5Л 575 B 1 .ii 20.0 t zs, o 11: 5 179 : 51 "2 Zjt i5 Table I o; o8 ctssr O. "12 BtCSS 0.616 5 (555 245L 6739 24.92 §T§ .392 -J3t9 "5166, 588 litifl 0.332720 0.350700 0.349716 0.350720 0.349725 0.3317B9 0.95 0.88 0.90 0.93 0.95 0.90 Table