RU2655633C1 - Concrete mixture - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: present invention relates to building materials, in particular to cast concrete mixtures, and can be used for manufacturing concrete and reinforced concrete structures with increased strength and crack resistance, as well as for concreting hard-to-reach places of structures and structures of complex configuration. Concrete mixture, including portland cement, quartz sand of medium size, granite fraction gravel 5–10 and mixing water, additionally contains microsilica, basalt fiber with a diameter of 1–3 mcm and length of 12–15 mm, a superplasticizer based on polycarboxylate ester Glenium ACE 40 in the form of an aqueous solution with a density of 1.04–1.08 g/cm³ with the following component ratio, mass%: portland cement – 15.0–19.0, granite fraction gravel of 5–10 mm – 35.2–36.9, quartz sand of medium size – 26.5–28.0, microsilica – 3.6–4.8, basaltic fiber – 5.1–6.0, superplasticizer based on polycarboxylate ester Glenium ACE 40 in the form of an aqueous solution with a density of 1.04–1.08 g/cm³ – 0.38–0.42, mixing water – 8.78–9.82.

EFFECT: technical result is increased mobility of the concrete mixture, reduced laboriousness of works in product molding, reduced equipment wear and, without overspending portland cement and while maintaining a low water-binding ratio, increased strength and crack resistance of products.

1 cl, 2 tbl

Description

 The present invention relates to building materials, in particular to cast concrete mixtures, and can be used in the manufacture of concrete and reinforced concrete structures with increased strength and fracture toughness, as well as in concreting inaccessible places of structures and structures of complex configuration.

Known concrete mixture comprising a binder containing a mixture of co-grinding Portland cement and a superplasticizer, crushed stone, sand and water, characterized in that a superplasticizer is additionally introduced into the concrete mixture, and silica additives in the form of quartz sand with traces of zirconium are added to the binder composition, wherein the co-grinding carried out before the specific surface area binder 5-7 m ² / g [RF patent №2147017 the invention "concrete mix, a method of manufacturing articles of concrete, the form for concrete with Thou ", the patent owner Stanislav V. Knyazev, Mironenko Sergey, Jankowski Yuri Fomichev, publ. 03/27/2000].

The disadvantage of this concrete mixture is the need for additional grinding of Portland cement with an additive-plasticizer and siliceous component, which leads to a significant increase in the cost of a binder, caused by the need to maintain and maintain additional main and auxiliary equipment for grinding, increasing the energy consumption necessary for the mill to work.

Known concrete mixture, including cement, sand, water and, as a reinforcing component, a modified continuous basalt fiber with a diameter of 350-400 microns, taken in an amount of 12-18% by weight of the mixture [patent application of the Russian Federation No. 94042107, IPC6 C04B 40/00 publ. 10.27.96].

However, large-diameter basalt fiber, taken in large quantities, is difficult to mix with in a mixture of cement and sand, so it takes a very long time to obtain a homogeneous mixture, which is technologically and economically disadvantageous.

The essence of the invention lies in the fact that the concrete mixture includes Portland cement, quartz sand, crushed stone and mixing water. The concrete mixture additionally contains silica fume, basalt fiber with a diameter of 1-3 microns and a length of 12-15 mm, a superplasticizer based on polycarboxylate ether Glenium ACE 40 in the form of an aqueous solution with a density of 1.04-1.08 g / cm3 in the following ratio of components, wt. %:

Portland cement 15.0-19.0 Granite crushed stone of fraction 5-10 35.2-36.9 Medium Quartz Sand 26.5-28.0 Silica fume 3.6-4.8 Basalt fiber 5.1-6.0 Glenium ACE 40 polycarboxylate ester superplasticizer in the form of an aqueous solution with a density of 1.04-1.08 g / cm ³ 0.38-0.42 Mixing water 8.78-9.82

The technical result is an increase in the mobility of the concrete mixture, a reduction in the laboriousness of the work during the molding of products, a decrease in the wear of equipment and, without overspending Portland cement and while maintaining a low water binder ratio, an increase in the strength and crack resistance of the products.

The introduction of the proposed concrete mixture additionally silica fume helps to increase the volume of the mortar in the composition of the concrete due to the low average density of silica fume compared to Portland cement. Thus, when replacing part of Portland cement by mass with silica fume, mobility increases in a freshly prepared concrete mixture, and strength and crack resistance increase in a finished concrete product.

The introduction into the proposed concrete mixture of an additional superplasticizer based on polycarboxylate ether significantly increases the water-reducing effect compared to conventional additives. The increase in the water-reducing effect of the introduced superplasticizer is based on the steric effect of polymers with linear transverse bonds of two- or three-dimensional form. Thus, the introduction into the proposed concrete mixture of a superplasticizer based on polycarboxylate ether leads to a decrease in sedimentation in the concrete mixture, an increase in mobility and a reduction in the laboriousness of work when molding products using the concrete mixture according to the invention.

Introduction to the proposed concrete mixture of additional basalt fiber with a diameter of 1-3 microns and a length of 12-15 mm increases the strength and crack resistance in the finished concrete product. The increase in the mechanical characteristics of concrete is due to the high adhesion strength of cement stone to fiber and basalt fiber itself under tension.

The inventive concrete mixture can be obtained using standard equipment in an industrial environment.

Examples of specific concrete mixtures according to the invention are given in table 1.

As cement, the mixture includes Portland cement CEM I 42.5 according to GOST 31108-2003. The mixture also includes granite crushed stone of a fraction of 3-10 mm and quartz sand of medium size.

Condensed silica fume MK-85 according to TU 5743-048-02495332-96, bulk density in the uncompressed state - 0.17-0.20 t / m ³ . Information about silica fume is presented, in particular, on the site http://microsilica-ural.ru / silica fume / technical specifications /.

Basalt fiber with a diameter of 1-3 microns, a length of 12-15 mm. Information on basalt fiber is presented, in particular, at https://ru.wikipedia.org/wiki/Basalt fiber.

Basf Glenium ACE 40 polycarboxylate ether superplasticizer is an aqueous solution with a density (at 20 ° C) of 1.04-1.08 g / cm ³ , information is provided, in particular, on the website http: //www.know-house. com / infotek / inf_pdf / 19_basf_39.pdf.

частью воды и перемешивали до однородного состояния. Суперпластификатор на основе поликарбоксилатного эфира смешивали с оставшейся

частью воды затворения и приливали в бетонную смесь и повторно перемешивали.The concrete mixture was prepared as follows: quartz sand, Portland cement, basalt fiber were mixed in dry form, after which crushed stone was introduced into the mixture and also thoroughly mixed. The resulting dry mixture was closed

part of the water and mixed until smooth. The polycarboxylate ester superplasticizer was mixed with the remaining

part of the mixing water and poured into the concrete mixture and re-mixed.

The concrete mixture prepared in this way has high mobility and does not require additional compaction when laying in the mold in the manufacture of concrete products. The resulting concrete mixture had a practical absence of delamination and sedimentation, high strength and crack resistance of concrete. The mobility of the resulting concrete mix is P5 (cone spread 60-62 cm), and the delamination did not exceed 2%.

The characteristics of strength and crack resistance of concrete prepared according to the invention, normal hardening at the age of 28 days are given in table 2.

Claims (2)

Concrete mixture including Portland cement, medium-sized quartz sand, crushed stone granite fractions 5-10 and mixing water, characterized in that it additionally contains silica fume, basalt fiber with a diameter of 1-3 microns and a length of 12-15 mm, a superplasticizer based on Glenium ACE polycarboxylate ether 40 in the form of an aqueous solution with a density of 1.04-1.08 g / cm ³ in the following ratio of components, wt.%: Portland cement 15.0-19.0 Granite crushed stone of fraction 5-10 35.2-36.9 Medium Quartz Sand 26.5-28.0 Silica fume 3.6-4.8 Basalt fiber 5.1-6.0 Glenium ACE 40 polycarboxylate ester superplasticizer in the form of an aqueous solution with a density of 1.04-1.08 g / cm ³ 0.38-0.42 Mixing water 8.78-9.82