RU2711169C1 - Crude mixture for producing fine-grained polymer concrete, modified with microsilice - Google Patents

Abstract

FIELD: construction.SUBSTANCE: present invention relates to production of construction materials and can be used for production of concrete articles and structures, sidewalk tiles, curbs, for setting of upper layers of roadway and their subsequent repair, as well as for repair of cracks and as filler of connecting seams. Concrete mixture includes portland cement, microsilice, sand, acrylic dispersion, water in following ratio of components, wt%: portland cement M500 20.8–21.0, microsilice MK-85 2.1–3.1, sand of 2.5–3.0 mm fraction 62.8–63.3, acrylic dispersion VDSM-KI-01-01 (latex) 0.10–0.13, water 12.7–13.0.EFFECT: production of frost-resistant material at reduction of production energy intensity.1 cl, 8 tbl

Description

The invention relates to the construction industry and may find application in the manufacture of nanomodified concrete based on potentially reactive coarse and / or fine aggregate for transport, industrial and civil construction.

The present invention relates to the production of building materials and can be used for the manufacture of concrete and reinforced concrete products and structures, paving slabs, borders, for the device of the upper layers of the roadway and their subsequent repair. And also for repairing cracks and as a filler for connecting joints.

In the modern and constantly developing world, in which the growing demand for building materials is proportional to the growth of scientific and technological progress, there is an urgent need for modernization of concrete, which allows them to be used in the construction of buildings and structures, bridges and viaducts, overpasses, highways and other critical structures, to which, at present, increased demands are made due to the increased load from a large number of cars, because of the massiveness of the structures being erected, de need to take into account the load from the building itself, etc. In this regard, building materials science has set itself the goal of developing new technologies for producing concrete with enhanced performance characteristics, while minimizing raw materials, energy and labor costs.

Currently, one of the most promising areas in construction is the modification of concrete through a complex of additives, this allows you to get concrete with improved technical and operational characteristics. One of such complexes of additives, the use of which makes it possible to obtain high-quality building material, is an acrylic dispersion and industrial waste - silica fume.

In Russia, silicon wastes were considered as potential raw materials relatively recently, while abroad they have been successfully used for 45 years. Russia has large volumes of silicon production wastes that are not used anywhere, despite the positive properties that concrete acquires after the introduction of silica fume.

Modification of the structure of cement stone by means of microsilicon from waste from silicon production and dispersion of acrylic will intensify binder hydration, reduce cement consumption and increase the strength characteristics of the final product, in comparison with traditional concrete mixtures.

Known raw mix for the manufacture of concrete, consisting of Portland cement, nanodispersed additives, sand and water (Putsenko KN Balabanov VB, Munkhtuvshin D., "Experience in the use of additives micro- and nanosilicon from waste from silicon production in concrete technologies", University News: Investments. Construction. Real Estate. 2017. V. 7. No. 3 (22). P.107-115 .; Balabanov VB, Putsenko KN, "Comparative analysis of the principal characteristics of microsilica obtained from silicon manufacture wastes and used in concrete production technologies ”, Collected: IOP Conference Series: Materials Science and Engineering Ser." International Conference on Construction, Architecture and Technosphere Safety, ICCATS 2017 " 2017.S.012011.).

Common signs are the use of nanodispersed additives in the composition of concrete - silica fume and a technical result aimed at increasing the compressive and bending strength of concrete at the age of 28 days, increasing durability and frost resistance.

The disadvantage of this raw material mixture for the manufacture of fine-grained concrete is its low compressive strength at the age of 28 days and a high probability of reducing the durability of structures due to a decrease in water demand due to the use of nanosized material - silica fume. In this regard, it was found that the effect is achieved only when using superplasticizer (for example, S-3, SP-1).

Known concrete mixture (RU No. 2616205, IPC C04B 28/04, C04B 24/04, C04B 24/24, C04B 14/06, C04B 111/20, published on 04/13/2017) used in the construction industry, which finds application in the manufacture nano-modified concrete based on potentially reactive aggregates for transport, industrial and civil engineering. Concrete is a mixture of components in the following ratio, wt. %:

Portland cement 25,125-27,228 Sand fraction 5-2.5 mm 6,126-6,239 Sand fraction 2.5-1.25 mm 15,316-15,600 Sand fraction 1.25-0.63 mm 15,316-15,600 Sand fraction 0.63-0.315 mm 15,316-15,600 Sand fraction 0.315-0.16 mm 9,190-9,360 Water 11,164-12,098 Polycarboxylate ester superplasticizer 0.041-0.045 Specified Nanoparticle (silica fume) 0.304-0.334

Common signs are the use of nano-additives in the composition of concrete - silica fume and the technical result is aimed at increasing the compressive strength of concrete at the age of 28 days and increasing its durability.

The disadvantage of this concrete mixture is a large range of limits at Portland cement and silica fume, which affects the amount of fine aggregate. The use of a more expensive brand of Portland cement M500 leads to a significant increase in the cost of concrete mix.

Known concrete mixture (Application RU No. 96108140, IPC C04B 28/04, C04B 24/26, C04B 18/04, C04B 14/12, published July 20, 1998), which is a mixture of cement stabilized with divinyl styrene latex, expanded clay gravel, expanded clay sand and water, characterized in that it contains ground unbaked spent molding sand and ground cupola slag in the following ratio of components, wt. %:

Cement 8.6-10.8 Stabilized divinyl styrene latex 2.5-5.4 Ground unburned molding sand 5.9-7.6 Ground cupola slag 2.5-3.2 Expanded clay gravel 31.8-37.7 Expanded clay sand 28.2-33.3 Water Rest

A common feature is the use of latex polymer in concrete.

The disadvantages of this concrete mixture are the lack of the specified scope and physico-mechanical characteristics of the resulting concrete.

The closest in technical essence is concrete mix (Application RU No. 2015124322, IPC C04B 28/04, published January 10, 2017), which relates to building materials and can be used for the manufacture of nanomodified concrete products in both civil and industrial construction . Concrete is a mixture of the following components: Portland cement, aggregate, mineral microfiller, microsilica, quicklime, plasticizer, polymer dispersion and water, characterized in that it contains polycarboxylate esters as a plasticizer, polyvinyl acetate or acrylic based redispersible powders as polymers, as a filler - a mixture of fractions of quartz sand, providing continuous granulometry with particle sizes from 0.08 to 2.5 mm. Concrete is a mixture of components in the following ratio, wt. %:

Portland cement 29-33 Quartz sand, fr. 0.16 ÷ 0.315 mm 25-41 Quartz sand, fr. 0.315 ÷ 1.25 mm 10-26 Silica fume MKU 85 6-8 Micro filler (Diabasite) 8-10 Quicklime 1-2 Plasticizer 1.4-2 Polymer 0.25-0.5 Water 5.5-6.5

Common signs are the use of nano-additives - silica fume as part of concrete, as well as a polymer dispersion, which are redispersible powders based on polyvinyl acetate or acrylic.

The disadvantage of this concrete mixture is the use in the total mass of a large amount of Portland cement and a relatively small amount of silica fume, thereby affecting the amount of fine aggregate. The use of more expensive grades of Portland cement can lead to a significant increase in the cost of concrete mix. Also, the disadvantage of this concrete mixture is the likelihood of low strength indicators and the occurrence of internal corrosion due to the use of superplasticizer based on polycarboxylate esters. The choice of the optimal dosage of superplasticizers based on polycarboxylate esters from the point of view of improving the physicomechanical characteristics of concrete is not a sufficient condition for the high durability of the structure, since there is a possibility of an alkaline silicate gel in the pores of the concrete and around the aggregate grains and, as a consequence, the expansion and cracking of the structure. (Sorvacheva Yu.A., Petrova T.M., Gibson K., Fedchenko A.L. Effect of polycarboxylate-based superplasticizer on alkali silicate expansion of concrete. Building materials. No. 5. - 2014, p. 15-21).

When choosing the optimal amount of polycarboxylate-based superplasticizer, it is necessary to evaluate not only their effect on the physicomechanical characteristics of concrete, such as density, porosity, strength, but also on the possible alkali-silicate expansion of concrete.

The results of the prototype studies did not indicate the density, hardening conditions, setting time, strength (grade and grade) and frost resistance of the resulting concrete.

The technical result is to increase the strength, frost resistance and quality of concrete.

The technical result is achieved in that the raw material mixture for the manufacture of fine-grained polymer concrete modified with silica fume, including Portland cement M500, a nanodispersed additive, sand, polymer (latex), water, according to the invention, contains MK-95 microsilica as a nanodispersed additive and, as polymers, acrylic dispersion VDSM-KI-01-01 (latex), as a filler - a mixture of quartz sand fractions with particle sizes from 2.5 to 3.0 mm, and the raw material mixture contains components in the ratio, wt. %:

Comparative analysis shows that the claimed method differs from the prototype, i.e. meets the requirements for the invention by the criterion of "novelty."

An additional comparative analysis of patent and scientific and technical information did not reveal sources containing information about the popularity of the set of distinctive features of the claimed invention, which indicates its compliance with the criterion of "inventive step".

To eliminate these drawbacks, a concrete mixture is proposed, consisting of Portland cement M500, nanodispersed additives, sand, polymer, water, characterized in that it contains microsilica MK-95 as nanodispersed additives, and acrylic dispersion VDSM-KI-01-01 as polymers (latex), as a filler - a mixture of fractions of quartz sand with particle sizes from 2.5 to 3.0 mm, and the raw material mixture contains components in the ratio, wt. %:

It is preferable to use condensed silica fume MK-95, Bratsk, with the following composition:

Physical properties of condensed silica fume MK-95

Before use, silica fume MK-95 is not subjected to additional treatments.

Portland cement M500 of the Angarsk cement plant was used as cement, quartz sand was used as sand for construction work of the Khrustalnaya Gora deposit (Yekaterinburg).

An acrylic dispersion V DSM-KI-01-01 (latex) (Irkutsk) was used as a plasticizing additive.

Hardening accelerators and air entraining additives were not used.

The method of preparation of concrete mix:

1. Sand is thoroughly mixed with cement, then silica fume is added;

1. Latex is mixed with water, after which it is introduced at seven and mixed thoroughly;

At this point, the mixture may be considered usable.

3. The mixture is compacted on a vibrating plate for 0.5-1.0 minutes.

The results of the tests are presented in the table:

Comparing the composition of the concrete mixture according to the prototype and the proposed composition of the concrete mixture with the addition of silica fume MK-95 and dispersion of acrylic VDSM-KI-01-01 (latex), the cost of the proposed mixture is lower than that of the prototype while maintaining all the requirements of GOST GOST 310.4-81, GOST 310.3-81, GOST 10181-2014, GOST 10181-2014, GOST 12730.1-78, GOST 10180-2012, GOST 10060-2012.

In addition, it should be noted that the use of such a concrete mixture requires low energy consumption, construction time is reduced, the material is frost-resistant.

Claims (2)

Raw mix for the manufacture of fine-grained polymer concrete modified with silica fume, including Portland cement M500, nanodispersed additive, sand, polymer, water, characterized in that it contains microsilica MK-95 as a nanodispersed additive, and acrylic dispersion VDSM-KI-01- as polymers 01 (latex), as a filler - a mixture of quartz sand fractions with particle sizes from 2.5 to 3.0 mm, and the raw material mixture contains components in the ratio, wt. %: Portland cement M500                                      20.8-21.0 silica fume MK-85                                       2.1-3.1 sand fraction 2.5-3.0 mm                                 62.8-63.3 dispersion acrylic VDSM-KI-01-01 (latex)  0.10-0.13 water                                                                        12.7-13.0