UA34487C2 - Method for manufacturing building products - Google Patents

Abstract

The invention relates to the light wood concretes and can be used at the production of building materials on the base of organic aggregates and cement.

Description

The invention relates to lightweight wood concrete and can be used in the production of building materials based on organic fillers and cement.

It is known that a construction material such as arbolite, filled with a sulfur mixture based on wood waste (sawdust, chips, bark, shavings, etc.), cement and water, quickly breaks down, mainly due to the formation of regenerating water-soluble sugars, which are cement poisons Water-soluble sugar - a product of the action of mold and wood-destroying fungi - reacts with calcium cement, reducing the rate of hardening of the latter and the strength of finished products. To eliminate undesirable consequences, as a rule, wood is treated with modifiers and accelerators of concrete setting are introduced.

There is a well-known method of obtaining arbolite, in which the wood filler is treated with cement heated to 150-2009С, taken in the amount of 15-2595 of its consumption per 1m3 of arbolite. Then the operation is repeated, mixing with the remaining cement, calcium chloride and water heated to 809

PI. The described method of energy storage, and the layer formed on the surface of wood particles does not ensure their localization from contact with moisture, therefore the strength increases slightly.

There is a known method of manufacturing cement chipboards, in which wood shavings are treated in a mixer with a concentrated bischofite solution by mixing, then a suspended portion of cement and water are added, the entire mixture is mixed until a homogeneous mixture is obtained, and the products are pressed (21.

The use of bischofite in addition to the mineralization of wood! it has an antiseptic effect on it, thus increasing the biostability of products, increasing their strength. However, products made by the specified method have relatively high thermal conductivity and low strength at a density of less than 1000 kg/M3. Strength increases only with large amounts of cement, which entails an increase in volumetric mass.

The closest in technical essence is the method of manufacturing wood-cement molded products by preparing a sulfur mixture from wood filler, cement and magnesium-containing components, which includes preliminary preparation and mixing of the components, closing and final mixing of the molding mixture (III.

In the specified technical solutions, wet or moistened wood filler is first mixed with crystalline sulfate or magnesium chloride or their mixture, as a sealing solution, a solution of a setting accelerator is prepared - burnt magnesite, or semi-burnt dolomite, or magnesia, or their mixture, which is mixed with cement add to the prepared wood filler and mix the mixture until homogenization. The molding mixture is loaded into the mold! and the material is exposed to heat and pressure for its hardening. The technical solution makes it possible to eliminate the side effect of using wood and makes it possible to use it in any form. The specified method is energy-saving and allows you to obtain products by dry or semi-dry molding by pressing, resulting in products with high density and thermal conductivity. The concentration of magnesium-containing components and their combination and the conditions of mixing the mixture indicate that the manufacturing process of the products follows the type of action of magnesium cement, thereby replacing part of the hydraulic binder.

The invention is based on the task of creating such a method of manufacturing construction products, in which, by changing the sequence of operations and preparing the components of the molding mixture, to ensure a decrease in the density and thermal conductivity of the products with increased strength, as well as to reduce the energy and labor intensity of the process due to the simplification of the technology.

The problem is solved by the fact that in the method of manufacturing construction products by preparing a sulfur mixture from wood filler, cement, and magnesium-containing components, which includes preliminary preparation and mixing of components, mixing and final mixing of the molding mixture, wood filler is mixed with cement in in a dry form, after which the mixture is closed with a solution of magnesium-containing components, and the latter is prepared by preliminary mixing of a 195% aqueous solution of dolomite sawdust - production waste during the calcination of dolomite - and a bischofite solution with a density of 1.05 g/cm, taken in a ratio of 1:100 .

The proposed method differs from the known prototype in the order of mixing the components, the mixing operation of the mixture and the composition of the mixing solution.

The claimed positive effect is achieved thanks to the following physical and chemical process. Wood filler of natural moisture (18-2295) when mixed with cement in dry form is coated with the latter to form a homogeneous cement-wood mixture. Dry cement forms a protective layer, absorbing moisture from the wood filler, preventing the release of water-soluble sugars and entering the initial phase of hydration. Cement, being a hygroscopic material, "draws" moisture from the capillaries of the wood filler, thereby freeing them to be filled with a grouting solution under a certain pressure, as a vacuum is created in the capillaries. The pre-prepared solution of the mixture at the specified concentration and ratio of components is a mixture of chloride, carbonate, sulfate, magnesium oxide in water and a small amount of other elements. The introduction of dolomite sawdust into a solution of dolomite sawdust - waste from the production of dolomite - a bischofite solution of the specified density changes the ratio between poorly soluble magnesium oxide and magnesium hydroxide, long chains -M4-0O-Ma-O0-Mu with hydroxyls or chlorine atoms are formed on ends with the formation of gel structures! magnesium oxychloride.

When mixing a wood filler with cement due to the reaction of its components with the components of the mixing solution, further hydration of the cement occurs. At the same time, the water is chemically bound all the time, the cement dough has low mobility, it easily fills all the pores of the wood filler, forcing air out. In addition, caustic magnesite, present in the solution of dolomite sawdust, is a pore former, particles! magnesium chloride play the role of additional crystallization centers. Due to the high mobility of the mixture, the pore formation is uniform, and the temperature of the mixture (reactions proceed with the release of heat) promotes swelling. Gas bubbles, remaining closed in the cement dough, increase the volume of the mixture after seizing. As a result of the reactions taking place, in addition to calcium silicates, magnesium silicate is formed, which has the ability to absorb and adsorb and participates as a catalyst in the hardening process of the molding mixture.

As a result, a light material with high strength and high thermal insulation properties is obtained.

A change in the concentration of the sealing solution to a greater or lesser extent leads to a violation of the process of uniform hardening and porosity of the molding mixture (fast or slow aggregation).

The set of essential features characterizing the essence of the invention, in principle, can be repeatedly used in the production of construction products, such as, for example, blocks, slabs.

Othod is used as a wood filler! processing of any wood species, sawdust, shavings, pre-shredded chips, bark and other plant waste or their mixture.

The essence of the proposed technical solution is explained by examples of the implementation of the method.

As sulfur components used!: portland cement grade 400, bischofite from the Poltava deposit with a density of 1.275 g/cm3 with a content of magnesium chloride 89.896, magnesium sulfate 3.2895, sodium chloride 6.48905, dolomite dust obtained by calcining dolomite, a waste product of Dokuchaevsky dolomite production - of that plant - with the content of magnesium (in terms of oxide) 3395, silicon (in terms of oxide) 1195, aluminum and iron (in terms of oxide, in total) 7,990, leave! wood - wood shavings, sawdust of Dokuchaevsky DOK with a humidity of 2290.

According to the proposed method, the process of manufacturing construction products includes: - preliminary preparation of the mixing solution - loading a metered amount of wood filler and cement into a concrete mixer and mixing them - mixing the mixture with a solution of magnesium-containing components and final mixing - pouring into molds and vibrating on a typical vibrating device (vibrating table) - unboxing after 24 hours.

Depending on the type of wood filler, its dispersion, as well as the ratio of the components of the filler and cement, it is possible to obtain material for different purposes. The mechanical strength of the products made by the proposed method allows the production of solid and hollow products.

We.

Example 1.

For the manufacture of wall blocks, the following was used per 1 m: Portland cement - 240 kg sawdust - Т00 l grouting solution - 200 l

The sealing solution was prepared in advance by adding dolomite sawdust to the aqueous solution of bischofite with a density of 1.05 g/cm3 in a ratio of 1:100 to the 195th aqueous solution.

Wood sawdust was loaded into a concrete mixer and mixed with cement for 2 minutes, then the resulting mixture was closed with a grouting solution and mixed for 3 minutes.

The resulting molding mixture was poured into a vertical cassette mold! and vibrated on a vibrating table for 1 minute. Formwork was made after 24 hours.

Wall blocks measuring (mm) 150x300x400 have: splitting strength 2.8 MPa compressive strength after 4 days 8.0 MPa density 690 kg/m3 thermal conductivity 0.08 kcal/m.h.grad. frost resistance of 35 cycles, output of products is 1.2 m3

Example 2.

For the manufacture of internal insulation blocks, we used: per 1 m3 of mixture: portland cement 100 kg of sawdust, 1 l of grouting solution 150 l

Technology by example 1. disassembly strength of products 2.0 MPa compressive strength after 4 days 6.2 MPa density 580 kg/m3 thermal conductivity 0.07 kcal/m.h.grad.

Example 3.

Board for the floor in size, (mm) 100x700x500 per 1 m3 of Portland cement mixture - 270 kg wood shavings - 600 l grout solution - 200 l

Technology according to example 1.

Formwork strength of products 4.0 MPa, compressive strength after 4 days 9.22 MPa density 930 kg/m3 thermal conductivity 0.1 kcal/m.h.degree

As can be seen from the examples given, the production of construction products from cement and wood filler by the claimed method allows the production of various types of products with good heat-insulating properties at high strength and low density.

In addition, the energy intensity of the technological process is reduced due to the exclusion of pre-treatment of wood and heat treatment operations. Construction products are ecologically clean, and the manufacturing process is safe for health, since the solution of the sealant has the property of healing wounds.

Circulation of 50 copies.

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