RU2284972C1 - Method of effective utilization as the fine filler of the siftings of the crushed stone from the igneous rocks - Google Patents

Abstract

FIELD: construction materials industry; methods of production of the fine-grain concretes.

SUBSTANCE: the invention is pertaining to the field of construction materials industry, in particular, to the method of effective utilization as the fine filler of the sifting of the crushed stone from the igneous rocks. The method provides for division of the crushed stone into fractions and fitting of the optimum granulometric composition of the indicated siftings. The indicated fitting is realized with production of concentration of the particles with the size of less than 0.16 mm - 15 %, the hollowness - no more than 38 %, and Mc - equal to 2.5-3.0. For production of the fine-grain concrete the concrete mixtures with W/C of no more than 0.6 are added with the organomineral additive МБ-10-01 in amount of up to 10 % of the mass of the cement or the plasticizer C-3 in amount of up to 1% from the mass of the cement, and for the fine-grain concrete based on the concrete mixtures with W/C exceeding 0.6 introduce the plasticizer C-3 in amount of up to 1 % from the mass of the cement for the indicated rocks of the fundamental composition or the organomineral additive МБ-10-01 in the amount of up to 10 % from mass of the cement for the indicated rocks of the acidic composition. The technical result of the invention is the strength improvement of the fine-grain concretes.

EFFECT: the invention ensures the strength improvement of the fine-grain concretes.

3 cl, 2 tbl

Description

The invention relates to the construction materials industry and can be used in the production of fine concrete.

A known method of using screenings for crushing crushed stone from igneous rocks (hereinafter screenings for crushing) in concrete is to enrich them, i.e. particle removal of less than 0.16 mm [1].

However, after enrichment, screenings of crushing must be applied in a mixture with natural fine sands to obtain equal strength concrete with concrete on natural sand. In addition, there is a deterioration in the frost resistance of concrete at enriched crushing screenings.

There is also a known method of using crushing screenings with a content of dusty and clay particles up to 10% by weight mixed with natural sand in fine-grained concrete with complex plasticizing and air-entraining additives [2]. This method in its technical essence and purpose is closest to the claimed and adopted as a prototype. However, the latter method does not allow to completely replace natural sand with crushing screenings to obtain high potential results.

The objective of the present invention is to obtain effective fine-grained concrete with screenings crushing with a high content of particles less than 0.16 mm It is solved by fractionation of crushing screenings and selection of their optimal particle size distribution with a high content of particles less than 0.16 mm, which are an active filler. The obtained fractionated sands from crushing screenings are used in concrete mixtures with modifying additives.

In this work, we used the organomineral additive MB-10-01, corresponding to the requirements of TU 5743-073-46854090-98, in an amount of up to 10% by weight of cement and plasticizing additive C-3 in an amount of up to 1% by weight of cement.

The essence and features of the invention are as follows. The method of effectively using crushed stone screenings from igneous rocks as a fine aggregate of screening crushing screenings differs in that it allows to completely replace natural sand with fractionated sand from screening screenings.

Another difference between the method of efficient use of crushed stone crushing screenings from igneous rocks as a fine aggregate consists in the separation of crushing screenings into fractions with the selection of the optimal particle size distribution of the obtained fractionated sands, based on the following provisions ensuring their good quality:

1. High content of fine fractions, including particles less than 0.16 mm

2. Voidness (Π) should not exceed 38%.

3. Sands should be large (Mkr = 2.5-3.0).

An example of selecting the optimal particle size distribution of fractionated sand from crushing screenings is shown in Table 1. Granite screenings are accepted as a representative of the crushing screening of acidic composition, and gabbro-diabase crushing screening is taken as a representative of the crushing screening of the main composition.

Table 1 Aggregate Private residues,%, on sieves with a hole size, mm CDM Π 5 2,5 1.25 0.63 0.315 0.16 <0.16 Initial dropout: gabbro diabase 28.7 9.1 13.9 16.5 10.8 6.0 15.0 3.22 40,2 granite 20,2 6.0 10.0 16.9 15,5 11.0 20,4 2.64 41.5 Sand fractioned from crushing screenings - 14.5 9.7 25.0 27.8 fourteen fifteen 2,53 35.1 - 14.0 10,2 23.0 22.2 15.6 fifteen 2,55 36.0

The third difference between the method of efficient use of crushed stone crushing screenings from igneous rocks as fine aggregate screenings is that fractionated sands from crushing screenings with an increased content of particles less than 0.16 mm, which are an active filler, can be used in fine-grained concrete based on very mobile and cast concrete mixes.

And the last difference of the proposed method for the effective use as a fine aggregate of screening crushing crushed stone from igneous rocks is to take into account the type and properties of screenings (acidic or basic composition) when assigning the type of additive. So, to increase the strength of fine-grained concrete on moving concrete mixtures (W / C not more than 0.6) with fractionated sands when assigning the type of additive. So, to increase the strength of fine-grained concrete on moving concrete mixtures (W / C not more than 0.6) with fractionated sand from crushing screenings of both acidic and basic composition, any of the additives is added: organomineral additive MB-10-01 or plasticizing additive C -3, and in fine-grained concrete on very mobile and cast concrete mixtures (H / C more than 0.6) when using sand fractioned from the screening crushing of the main composition, plasticizing additive C-3 is introduced, and for sand fractionated from the screening crushing acidic Ava - Organo-additive MB-10-01.

The physico-chemical basis for the effective use of crushing screenings is the ability of particles less than 0.16 mm of screening screenings to enter into chemical interaction with Portland cement neoplasms with the formation of complex hardly soluble calcium hydrosilicates, which ensures the strength of the cement matrix. In addition, the proposed method uses the hydrophobic-hydrophilic properties of the particle surface of less than 0.16 mm, which makes it possible to obtain effective fine-grained concrete, including based on very mobile and cast concrete mixtures (W / C more than 0.6).

Acid crushing screenings having a hydrophilic surface are characterized by a high adsorption capacity of particles of less than 0.16 mm with respect to water, which provides a dense and strong structure of fine-grained concrete based on very mobile and cast concrete mixtures (H / C more than 0.6) . The use of organomineral additives MB-10-01 based on silica fume increases the mobility of the concrete mixture, and therefore, the efficiency of using the properties of particles less than 0.16 mm In addition, the density of the cement stone of fine-grained concrete with screenings of crushing acid composition increases.

For crushing screenings of the basic composition having a surface with low hydrophilicity, a lower adsorption capacity of particles of less than 0.16 mm with respect to water is characteristic. In this case, the plasticizing additive C-3 is used. On a low-hydrophilic surface of particles of less than 0.16 mm of screenings of crushing of the main composition, surfactant molecules are hydrophobic in solution, which hydrophilizes the surface. As a result of the use of additive C-3 with screenings of crushing of the main composition against the background of increased mobility of the concrete mixture, the strength of the cement stone both in the contact zone and in volume increases.

Table 2 shows examples of the effective use of acidic and basic composition fractionated sands from crushing screenings as fine aggregate. For comparison, data are given on the strength of fine-grained concrete on natural fractionated sand.

table 2 No. p / p Type of sand fractionated additive The amount of additive,% by weight of cement Ok see W / C The strength of fine-grained concrete. R _compress kgf / cm ² TVO 28 days one natural - - 5 0.56 122 200 2 from screening crushing granite ^- - 5 0.7 152 245 3 from screening crushing gabbro diabase - - 5 0.7 130 205 four natural MB-10-01 9 10.5 0.7 142 230 5 from screening crushing granite MB-10-01 9 10.5 0.7 220 358 6 from screening crushing gabbro diabase MB-10-01 9 11.0 0.7 150 242 7 natural S-3 0.9 6.5 0.5 140 220 8 from screening crushing granite S-3 0.9 7 0.7 120 190 9 from screening crushing gabbro diabase S-3 0.9 7 0.7 164 260 10 from screening crushing granite MB-10-01 9 2,5 0.5 335 550 eleven from screening crushing gabbro diabase S-3 0.9 2 0.5 252 468

Information sources:

1. Anisimova E.I. Zolnikova G.S. The experience of using crushing screenings as fine aggregates for concrete // Abstracts of the All-Union meeting "Intensification of the production of non-metallic building materials" (Pavlovsk, September 20-22, 1989) / Central Voronezh region. board of VITostroyindustriya. - M .: Stroyizdat. - 1989. - S.232-236.

2. Jacobson M.Ya. Road concrete using screenings of crushing of igneous rocks for the construction of roads. - The dissertation for the degree of candidate of technical sciences. - Moscow. - 2000. - 258 S.

Claims (3)

1. The method of effective use as fine aggregate for fine-grained concrete screenings of crushing crushed stone from igneous rocks, comprising dividing them into fractions and selecting the optimal particle size distribution of these screenings, characterized in that the selection is carried out with a particle content of less than 0.16 mm 15%, voidness not exceeding 38%, and microcirculation, equal to 2.5-3.0. 2. The method according to claim 1, characterized in that for fine-grained concrete on concrete mixtures with W / C not more than 0.6, an organomineral additive MB-10-01 is introduced in an amount of up to 10% by weight of cement or a plasticizing additive C-3 in the amount of up to 1% by weight of cement. 3. The method according to claim 1, characterized in that for fine-grained concrete on concrete mixtures with a W / C greater than 0.6, plasticizing additive C-3 is introduced in an amount of up to 1% by weight of cement for the specified rocks of the main composition or organomineral additive MB- 10-01 in an amount up to 10% by weight of cement for the indicated rocks of acidic composition.