RU2255920C1 - Raw mixture for making light concrete - Google Patents

Abstract

FIELD: building industry and materials.

SUBSTANCE: invention relates to manufacturing structurally heat-insulating light concretes on porous filling agent and can be used for making alleviated building articles, blocks and constructions for different designation in assembly and monolith building. Raw mixture for producing light concrete comprising cement, porous filling agent and water involves granulated foam-glass of spherical form of fractions 5-40 mm with the volume filled mass 180-200 kg/m³ as a porous filling agent, and sodium water glass as a chemical additive in the following ratio of components, wt.-%: cement, 46-48; ash fly from heat and electric power plant, 16-18; granulated foam-glass, 18-20; sodium water glass, 1.38-1.44; foam-forming agent "Belprom-1om", 0.78, and water, the balance. Invention provides manufacturing long-lived building material with improved strength and heat-insulating properties, reducing consumption of binding agent and stabilizing the cellular structure due to addition of a porous filling agent.

EFFECT: improved properties of raw mixture.

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Description

The invention relates to building materials, namely, compositions, mainly to the production of structurally-heat-insulating and heat-insulating lightweight concrete on porous aggregate, and can be used for the manufacture of lightweight building parts, blocks and structures for various purposes in prefabricated and monolithic construction.

A known raw material mixture (SU 1320201, class C 04 B 38/10, 06/30/87. Bull. No. 24) for expanded clay concrete using spherical expanded clay as a porous filler.

This invention has several disadvantages, namely the manufacture of expanded clay from a raw mix of photo gelatin production waste and aluminum etching waste, which complicates the preparation technology and requires additional investment and energy costs for the production of aggregate.

Known compositions of sandless lightweight concrete, porous with foaming additives, and large-pore lightweight concrete / Bazhenov Yu.M. Methods for determining the composition of concrete of various types. M .: Stroyizdat, 1975, pp. 154-155 /.

The manufacture of such mixtures is characterized by a relatively high consumption of cement, a high coefficient of thermal conductivity and significant energy costs for obtaining the applied porous aggregate, as well as investment in the production and modernization of equipment.

Of the known technical solutions, the closest analogue is the composition of expanded clay concrete prepared from a mixture of a binder, porous aggregate (expanded clay gravel), a foaming agent, a chemical additive, and water. Sometimes, to reduce the consumption of cement, siliceous components (finely ground or dusty) are added to the mixture. Preparation of concrete mix includes the preparation of a foam concrete mass, and then its mixing with expanded clay gravel / Kiselev D.P. and other porous lightweight concrete. M., Publishing House of Construction Literature, 1966, pp. 7-9, 12-13, 115-116 /.

High cement consumption, the presence of a fine fraction in the porous aggregate increase the bulk density of concrete and reduce the thermal conductivity of the material. To reduce the density of porous expanded clay concrete, various additives, industrial wastes, etc. are introduced into the mixture. The use of additives and their preparation complicate the technology for preparing concrete mixtures, slightly reducing the density of concrete and cement consumption.

The objective of the invention is to obtain a durable building material with improved strength and heat-insulating properties, reducing the consumption of binder and stabilizing the cellular structure of concrete by introducing a porous aggregate.

The specified technical result is achieved by the fact that in a concrete mixture containing cement, fly ash of a thermal power station, a foaming solution, a chemical additive is liquid sodium glass, a porous aggregate and water, according to the invention, granular foam glass of various fractions or a mixture of fractions is used as a porous aggregate. The process of obtaining the mixture is characterized by separate preparation (cement, fly ash of thermal power plants, liquid sodium glass, water), separate preparation and introduction of foam into the concrete mixture, introduction of porous aggregate (granulated foam glass), as well as a continuous mixing process until the mineral binder is completely enveloped in an aqueous dispersion surface of the porous aggregate. In this case, the foam concrete used may contain mineral binders, a foaming agent and water or mineral binders, a foaming agent, a siliceous component and water, in the following ratio of components,%:

Cement 46-48

Fly ash CHP 16-18

Granular foam glass 18-20

Liquid sodium glass 1.38-1.44

Foaming agent “Belpor-1om” 0.78

Water The rest.

For the implementation of the invention used the following components:

- Portland cement M 400 (Topki, Kemerovo region) must meet the requirements of GOST 10178-95.

- Fly ash CHPP-4, (Omsk) according to GOST 25818-91, with a bulk density ρ _n = 600 kg / m, specific surface - 3.5-5.0 thousand cm / g.

- Sodium liquid glass according to GOST 13078-81 with ρ = 1400 kg / m ³ .

- Protein blowing agent “Belpor-1om” (Omsk) according to TU 0258-001-03899386-99.

- Porous aggregate - granular foam glass (Omsk, pos. Luzino) TU 5914-001-00643867-94, GOST 9758-86 fractions 5-10, 10-20, 20-40 and 5-40 mm ρ ^us = 180- 200 kg / m ³ .

- Water for concrete and mortar according to GOST 23732-79.

Initially, a concrete mixture was prepared by mixing in a laboratory mortar mixer with a capacity of 15 liters. The sequence of loading the mixer with the constituent materials was as follows: preparation of the concrete mixture (cement, fly ash of the thermal power station, liquid sodium glass, water), introduction of technical, pre-prepared foam with subsequent mixing and obtaining a uniform foam concrete mixture. Next, the porous aggregate was gradually introduced into the prepared foam concrete mixture with continuous mixing of the mixture for 0.5-2.5 min until the granules of the aggregate were completely distributed and enveloped in the foam concrete mixture. A time limit is necessary to maintain the integrity of the foam glass granules from crushing with stirring.

The concrete mass was placed in metal molds with a mesh size of 10 × 10 × 10 and 15 × 15 × 15 cm, 12 hours were kept until the formwork strength was set, after which the prepared samples were subjected to heat treatment for 12 hours at a temperature of 80-85 ° С. Half of the samples were tested 4 hours after heat treatment, the rest at the age of 28 days of storage in a normal hardening chamber at a temperature of 20 ± 2 ° C and a relative humidity of 95%.

Tests of the mixture and samples were carried out in accordance with the requirements of GOSTs and test methods for building mixtures and materials.

The tests showed that the introduction of a porous aggregate of a porous aggregate (granular foam glass) can improve the physicomechanical and thermal insulation properties of concrete (Table 1).

Table 1. Composition Bulk weight, kg / m ³ Strength, MPa Freshly made foam concrete mix Aggregate fraction, mm Freshly made foam glass * mix Foam glass * after TVO Dried condition before fasting. masses After TVO after 3 days After TBO after 28 days 1 800 10-20 695 600 532 1.20 1,69 2 810 10-40 640 530 465 1.22 1,58 3 830 10-40 710 655 580 1.15 1.55 4 840 10-20 675 620 500 1,53 1.94 5 940 10-20 795 630 520 1.75 2.21 6 940 20-40 765 743 670 1.10 1.45 Note:
1. Preferably, it is necessary to achieve, when preparing the concrete mixture, so that the density of the foam concrete is as close as possible to the density of the porous aggregate used, in order to avoid delamination of the mixture.
2. The bulk density of granulated foam glass 200 kg / m ³ .
3. The thermal conductivity of the samples * in the dry state of 0.09 -0.12 W / m ° C.
* Foam-glass concrete mixture or foam-glass concrete is a composition consisting of a binder - cement, a siliceous component - fly ash of a thermal power station, a foaming agent - "Belpor-1om", a chemical additive - liquid sodium glass, a porous filler - granular foam glass and water.

It differs from known methods in that it contains a composition * that includes the necessary components (binder, silica component, foaming agent, chemical additive and water), as well as the use of less energy-intensive and cheaper porous aggregate with low thermal conductivity, which reduces the volumetric concentration of cement stone stabilization of the cellular structure of concrete and obtaining a material homogeneous in volumetric mass with high heat-shielding properties and strength characteristics.

The use of less energy-intensive technologies and cheaper components of local production and waste in the concrete mixture (granular foam glass obtained from the battle of container and building glass, fly ash of thermal power plants and foaming agent obtained from cattle waste and poultry farms) significantly affects the cost of products and the environmental situation in the town.

Physico-mechanical properties of concrete: tempering strength after heat treatment 0.8-1.5 MPa, strength for 28 days 1.5-2.2 MPa, frost resistance grade F 50, dry heat conductivity coefficient 0.09-0, 12 W / (m · ° С), which meets the requirements of GOSTs and SNiP 11-3-79 * “Construction heat engineering”.

Figure 1-4 shows photographs of samples.

Claims (1)

Raw mix for the manufacture of lightweight concrete, including cement, fly ash of a thermal power station, a foaming solution, a chemical additive, a porous aggregate and water, characterized in that it contains granular foam glass of spherical shape of fractions 5-40 mm with a bulk density of 180 as a porous aggregate -200 kg / m ³ , as a foaming agent solution - Belpoor-1om foaming agent, and as a chemical additive - liquid sodium glass in the following ratio of components, wt. %: Cement 46-48 Fly ash CHP 16-18 Granular foam glass 18-20 Liquid sodium glass 1.38-1.44 Foaming agent “Belpor-1om” 0.78 Water Else

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