RU2527447C1 - Composite construction material - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: composite construction material comprising a cement binder, a filler, lignocellulose materials and an additive - a mixture of low molecular polyethylene and urea at the ratio of 1:1, additionally contains a non-ionogenic surfactant polyvinyl pyrrolidone at the following ratio of components, wt %: cement binder 20-30, filler 44-56, non-ionogenic surfactant polyvinyl pyrrolidone 0.5-2, lignocellulose materials 5-12, mixture of low molecular polyethylene and urea at the ratio of 1:1 0.5-3.5, water - up to 100.

EFFECT: development of a composite construction material to manufacture concrete products, making it possible to increase compressing strength, cone slump, tensile strength in bending, elasticity modulus and to reduce water absorption.

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Description

FIELD OF TECHNOLOGY

The invention relates to the composition of composite building materials, including a cement matrix reinforced with cellulose-containing materials, and can be used in the building materials industry in the manufacture of precast, monolithic and precast-monolithic concrete and reinforced concrete structures, products for buildings and structures for various purposes.

BACKGROUND

A fiber reinforced polymer modified cement composition is known. The specified composition contains a mixture of 0.1-15% emulsion of the polymer (calculated on the dry residue) with a glass transition temperature of -25 - (+ 150) °, cement, cellulose fibers, sand and water. So, for example, the composite is obtained from a mixture containing, mass. including: 200 sand, 100 cement, 30 fibers, 44 water and 10 polymer containing 4% surfactant. The introduction of a cement-resistant polymer increases the bending strength of the composite after curing in an autoclave by almost 2 times [Polymer-modified fiber-cement composition: US Patent 7148270. Publ. December 12, 2006].

However, the process of molding a composite from this mixture requires a long time: water is removed by drying at 25 ° C and 55% relative humidity for 1 week, then it is autoclaved at a temperature 10 ° higher than the glass transition temperature of the polymer (for example, 7 hours at 170 ° for acrylic copolymer).

Known fiber cement composite material [Fiber cement composite materials using cellulose fibers loaded with inorganic and / or organic substances: US Patent 6676744. Publ. 01/13/2004] with cellulose fibers filled with inorganic and / or organic substances, containing a cement matrix in which cellulose fibers are distributed, the pores of which are partially filled mainly with insoluble inorganic or organic substances that impede the penetration of water, in which the starting components are taken in the following ratios, wt.%:

Cement binder 10-80 Aggregate 20-80 Density modifier 0-50 Inorganic cellulose fibers or organic matter 0.5 20 Additives 0-10 Water up to 100

However, this composite material has not high enough indicators: ultimate compressive strength; tensile strength in bending; modulus of elasticity, cone sludge and workability, and also includes an additional operation for filling cellulose fibers with inorganic and / or organic materials.

The closest in technical essence and the achieved result, that is, the prototype, is a composite building material intended for the manufacture of concrete products [Composite building material: RF Patent 2410345. Publ. January 27, 2011], containing a cement binder, aggregate, density modifier, lignocellulosic materials and an additive that contains concentrated waste products of caprolactam as a density modifier, spent sorbents for wastewater or process water treatment containing heavy metal salts and lignocellulosic materials representing a cellulose-containing waste of the agricultural complex, and as an additive - dry vinasse in the following ratio of components, wt.%:

Cement binder 17-25 Aggregate 50-65 Density modifier 0.5-2 Lignocellulosic materials 2.45-13.75 Additive 1-3 Water up to 100

The following ingredients are used to prepare composite building material:

- cement binder: Portland cement and slag Portland cement, cement for mortars, sulfate-resistant cements;

- aggregate: gravel and expanded clay sand, shungizit gravel, natural and crushed sands, sand for construction work, crushed stone and sand from porous rocks, ash and slag mixtures of thermal power plants for concrete;

- density modifier: concentrated waste products of caprolactam production;

- lignocellulosic materials: sawdust, sunflower husk, chopped Jerusalem artichoke stalks, straw containing salts of heavy metals, for example, sulfates, chlorides, nitrates, acetates Cu (II), Zn (II), Cd (II), Ni (II), Fe (II) et al .;

- additive: dry bard, which is a waste in the production of ethyl alcohol from a mixture of wheat and rye - brown fine powder of dark brown color with a pleasant (bread) smell, containing protein (up to 30%) and cellulose (about 13-21%) components ;

- water for concrete and mortar.

The disadvantages of the prototype are not high enough: ultimate compressive strength; sediment cone; tensile strength in bending; modulus of elasticity and high water absorption.

SUMMARY OF THE INVENTION

The objective of the invention is to create a composition of a composite building material for the manufacture of concrete products, which allows to increase the tensile strength in compression; draft of the cone; tensile strength in bending; modulus of elasticity and reduce water absorption.

The problem is solved by a composite building material containing a cement binder, aggregate, lignocellulosic materials and an additive that, as an additive, contains a mixture of low molecular weight polyethylene and urea in a ratio of 1: 1 and additionally contains a nonionic surfactant in the following ratio of components, wt.%:

Cement binder 20-30 Aggregate 44-56 Nonionic surfactant 0.5-2 Lignocellulosic materials 5-12 A mixture of low molecular weight polyethylene and urea in the ratio 1: 1 0.5-3.5 Water up to 100

For the preparation of the claimed cement composite construction material intended for the manufacture of concrete products, the following ingredients are used:

- Cement binder: Portland cement and slag Portland cement. Technical conditions [GOST 10178-85]; cement for mortar. Technical conditions [GOST 25328-82]; sulfate-resistant cements. Technical conditions [GOST 22266-94].

- Aggregate: gravel and expanded clay sand. Technical conditions [GOST 9759-76]; gravel shungizitovy. Technical conditions [GOST 19345-73]; natural and crushed sands. Technical conditions [GOST 8736-77 and GOST 10268-80]; sand for construction work. Technical conditions [GOST 8736-93]; crushed stone and sand from porous rocks. Technical conditions [GOST 22263-76]; mixtures of ash and slag of thermal power plants for concrete. Technical conditions [GOST 25592-91].

- Nonionic surfactant polyvinylpyrrolidone is an amorphous linear polymer with a molecular weight of from 10 ³ to 10 ⁶ . Hygroscopic, soluble in water, non-toxic, has an affinity for organic polymers.

Aqueous solutions have a slightly acid reaction (pH 5) [TU 9365 002-46270704-2001. Polyvinylpyrrolidone high molecular weight "Polydon"]. Polydon is a water-polymer composition in the form of a sol or gel of high molecular weight polyvinylpyrrolidone.

- Lignocellulosic materials: sawdust, sunflower husk, chopped Jerusalem artichoke stalks, straw containing salts of heavy metals, for example, sulfates, chlorides, nitrates, acetates Cu (II), Zn (II), Cd (II), Ni (II), Fe (H) et al.

- Additive: a mixture of low molecular weight polyethylene NMPE-1 (waste from the production of high pressure polyethylene) - [TU 2211-060-00203521 - 2002] and urea (urea) (Specifications [GOST 2081-92] - (NH ₂ ) ₂ (CO) ) in a ratio of 1: 1.

- Water for concrete and mortar. Technical conditions [GOST 23732-79].

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

Example 1

A cement binder of 20 wt.% And aggregate of 56 wt.% Are loaded into the mixer and mixed with the formation of a solid mixture, then 7 wt.% Water is added and all mixed with the formation of a dense mass into which a non-ionic surfactant Polydon 1.5 wt. % and lignocellulosic materials, which are waste sorbents for wastewater or process water treatment, containing heavy metal salts (sawdust) 12 wt.% and a mixture of low molecular weight polyethylene and urea in a ratio of 1: 1-3.5 wt.%, after which everything is mixed with thick Assa until a uniform composition, the composition is poured into a mold and cured it for 24 hours at a temperature of + 130 ° C to form a solid constructional building material. Ready-made cement structural building material can be machined, cut and painted.

Example 2

A cement binder of 23 wt.% And a filler of 57 wt.% Are loaded into the mixer and mixed with the formation of a solid mixture, then 7 wt.% Water is added and everything is mixed to form a thick mass into which a nonionic surfactant Polydon 1 wt.% Is added, lignocellulosic materials, which are waste sorbents for wastewater or process water treatment, containing heavy metal salts (ground Jerusalem artichoke stalks) 10 wt.% and a mixture of low molecular weight polyethylene and urea in a ratio of 1: 1-2 wt.%, after which everything is mixed dissolved with a dense mass until a uniform composition, the composition is poured into a mold and cured it for 36 hours at + 5 ° C to form a solid constructional building material. Ready-made cement structural building material can be machined, cut and painted.

Example 3

A cement binder of 30 wt.% And aggregate of 50 wt.% Are loaded into the mixer and mixed together to form a solid mixture, then 11 wt.% Water is added and the whole is mixed to form a thick mass into which a nonionic surfactant Polydon 0.5 wt. %, lignocellulosic materials, which are waste sorbents for wastewater or process water treatment, containing heavy metal salts (short flax fiber) 8 wt.%, and a mixture of low molecular weight polyethylene and urea in a ratio of 1: 1-0.5 wt.%, after which all mixed with thick mass until a homogeneous composition is formed, this composition is poured into a mold and solidified for 28 hours at a temperature of + 100 ° C to form a solid structural building material. Ready-made cement structural building material can be machined, cut and painted.

Example 4

A cement binder of 22 wt.% And aggregate of 60 wt.% Are loaded into the mixer and mixed together to form a solid mixture, then 10 wt.% Water is added and the whole is mixed to form a thick mass into which a nonionic surfactant Polydon 0.8 wt. %, lignocellulosic materials, which are waste sorbents for wastewater or process water treatment, containing heavy metal salts (sunflower husk) 5 wt.% and a mixture of low molecular weight polyethylene and urea in a ratio of 1: 1-2.2 wt.%, after which everything is mixed with thick mass until a homogeneous composition is formed, this composition is poured into a mold and cured for 30 hours at a temperature of + 75 ° C to form a solid structural building material. Ready-made cement structural building material can be machined, cut and painted.

Example 5

A cement binder of 28 wt.% And aggregate of 44 wt.% Are loaded into the mixer and mixed with the formation of a solid mixture, then water is added 12 wt.% And everything is mixed to form a thick mass into which a nonionic surfactant Polydon 2 wt.% Is added, lignocellulosic materials, which are waste sorbents for wastewater or process water treatment, containing heavy metal salts (straw) of 11 wt.% and a mixture of low molecular weight polyethylene and urea in a ratio of 1: 1-3 wt.%, after which everything is mixed with a dense mass to the sample mations homogeneous composition, this composition is poured into a mold and cured it for 32 hours at + 50 ° C to form a solid constructional building material. Ready-made cement structural building material can be machined, cut and painted.

The inventive composite building material, as well as concrete based on it, were tested by the following indicators: sediment cone of the concrete mixture according to [GOST 10181-2000: Concrete mixtures. Test Methods]; ultimate compressive strength (after 3, 7 and 28 days) and tensile strength in bending - according to [GOST 10180-2012. Concrete Methods for determining the strength of control samples]; modulus of elasticity - according to [GOST 24452-80. Concrete Test methods].

The table shows the test results of the compositions of the claimed composite building material and the composition of the prototype.

The table shows that when testing concrete samples made from the inventive composite building material, indicators such as tensile strength in compression, tensile strength in bending, elastic modulus and draft of the cone increase by an average of 5-14%; water absorption is reduced by 40-47% compared with the prototype.

The claimed composite building material retains all the advantages of the prototype, such as good fire retardant properties, low water adsorption rate and reduced water permeability due to the presence of metal salts in cellulose-containing materials, as these substances penetrate deep into the fibers and inhibit the migration of water in the cement composite material. The presence of metal ions also imparts insectofungicidal and bactericidal properties. The additive containing low molecular weight polyethylene (NMPE) and urea additionally gives the concrete hydrophobic (water-repellent) and plastic properties, and Polydon helps stabilize the dispersed system.

Claims (1)

Composite building material containing a cement binder, aggregate, lignocellulosic materials and an additive, characterized in that as an additive it contains a mixture of low molecular weight polyethylene and urea in a ratio of 1: 1 and additionally contains a nonionic surfactant polyvinylpyrrolidone in the following ratio of components, wt.%:
Cement binder 20-30 Aggregate 44-56 Nonionic surfactant polyvinylpyrrolidone 0.5-2 Lignocellulosic materials 5-12 A mixture of low molecular weight polyethylene and urea in the ratio 1: 1 0.5-3.5 Water up to 100