RU2751628C1 - Composition of composite material for the manufacture of asphalt concrete pavement - Google Patents

Abstract

FIELD: road-building mixtures.

SUBSTANCE: invention relates to the field of road-building mixtures, in particular to the production of modern material for road surfaces with improved physical and mechanical properties. The mixture includes the following components: a composite binder of one bitumen of the first row - CB (Construction Bitumen) 90/130, CB 60/90, CB 40/60 together with one of the bitumen of the second row - CB 200/300, CB 130/200 with a predominance of the first row bitumen in the binder; composite reinforcing fibromaterial of polyacrylonitrile (PAN) and basalt fibers with a predominance of PAN fibers in the fibromaterial; mineral powder, sand. The components are contained in the following ratio: reclaimed crushed asphalt concrete and mineral powder formed from particles with a size of not more than 1.25 mm of reclaimed crushed asphalt concrete, and constituting 10-20% of the amount of the latter in the total amount - 24-25%. Composite binder, in which bitumen of the first and second rows are presented as follows: bitumen of the first row - 85-95%, that of the second row - 5-15% - in a total amount of 4-8%, oleic acid 0.2-0.6%, composite reinforcing fibromaterial in the amount of 0.15-0.7%, in which PAN is 60-95%, basalt fiber - 5-40%. Sand is the rest.

EFFECT: improvement of the physical and mechanical strength characteristics of asphalt concrete, in particular those of water resistance and shear resistance.

1 cl, 2 tbl, 1 ex

Description

The invention relates to the field of road-building mixtures, in particular to obtaining a modern material for a road surface with improved physical and mechanical properties.

The use of industrial waste to obtain competitive products is one of the urgent tasks of lean production. In the road construction industry, the recycling of used old roadways by incorporating them into new pavements is becoming more common.

There are various compositions of mixtures for creating asphalt clothes, obtained by various technologies using reclaimed asphalt concrete material, described in foreign patent sources:

- in the patent EP for invention No. 0182937,

- in US patent for invention No. 4559128,

- in US patent for invention No. 8206500,

- in the KR patent for invention No. 101487180,

- in the KR patent for invention No. 101654614.

Along with the economy of raw materials due to the exclusion of filling components, which can be dispensed with in the case of reclaimed material, the introduction of reclaimed asphalt concrete into the mixture in the above inventions requires preliminary preparation: if necessary, washing, crushing, division into fractions, etc. This increases the cost of the newly produced asphalt pavement on the other hand.

Russian uses of reclaimed asphalt are also known, set out in more detail below.

Known asphalt mixture described in RU patent for invention No. 2460703. The mixture contains bitumen, crushed stone, natural and crushed sand and mineral powder. As the latter, it contains cakes - waste from the production of non-ferrous metals and limestone flour in a ratio from 1: 2.3 to 1: 1.5. The ratio of the components in the mixture is as follows, wt%: petroleum bitumen - 5.2-5.7, crushed stone - 19.0-23.5, crushing screenings - 47.2-52.1, natural sand - 17.9-19 , 0, mineral powder - 4.7-5.7.

Also known is the composition of polymeric asphalt from milled old asphalt concrete, described in RU patent for invention No. 2702434. The composition includes asphalt concrete removed from the upper part of the road surface, heated to 40-60 ° C, binder 0.5-5%, including diesel fuel and a modifier. The modifier contains divinylstyrene thermoplastic elastomer, heat carrier oil AMT-300, polyethylene polyamine, a mixture of fatty acids of vegetable oils, including oleic acid.

The disadvantage of the above technical solution is a large set of activating and modifying components, each of which requires a special technology of introduction into the overall composition of the mixture, when deviating from which the effect is not guaranteed. In addition, each above the minimum required components additionally has a cost.

There is also known a solution - patent No. 2345967, in which an attempt is made to combine oleic acid and basalt microfiber in one mixture for repairing an asphalt concrete pavement. A mixture for the repair of asphalt concrete road surfaces contains: bitumen 4.5 ÷ 7% by weight of crushed stone, diesel oil 20 ÷ 25% by weight of bitumen, oleic acid 8 ÷ 16% by weight of bitumen, polyethylene polyamine 5 ÷ 12 by weight of bitumen, nanomodified basalt microfiber 1 ÷ 3% by weight of bitumen, cellulose microfiber 3 ÷ 5% by weight of bitumen.

The closest analogue to the claimed invention is the composition described in RU patent for invention No. 2713015. It includes,%: crushed stone 20-60, mineral powder 4-12, organic binder 4-12, reinforcing material 0.07-0.6, sand - the rest. In this case, the reinforcing material is represented by a set of basalt fiber with a density of 54-240 tex with a cut length of 12-18 mm in an amount of 5-40% of the total amount of reinforcing material and polyacrylonitrile fiber (PAN) with a density of 0.17-0.77 tex with a cut length of 6 -18 mm in the amount of 60-95% of the total amount of reinforcing material. Organic binder is a composite of two types of viscous oil road bitumen, in% of the total amount of binder in the mixture: bitumen of one of the grades: BND 90/130, BND 60/90, BND 40/60 - 85-95 together with bitumen of one of the grades : BND 200/300, BND 130/200 - 5-15.

However, this asphalt concrete composition does not take into account all the possibilities for improving the physicochemical parameters, as well as environmental and other indicators.

The objective of the claimed invention is to improve water resistance, strength performance characteristics of the resulting coating: shear stability, rutting resistance, crack resistance and environmental friendliness increase.

The essence of the claimed invention is characterized by the fact that the composition of the composite material for the manufacture of asphalt concrete pavement, including: a composite binder of one bitumen of the first row - BND 90/130, BND 60/90, BND 40/60 together with one of the bitumen of the second row - BND 200 / 300, BND 130/200 with predominance of first row bitumen in the binder; composite reinforcing fibromaterial of polyacrylonitrile (PAN) and basalt fibers with a predominance of PAN fibers in the fibromaterial; mineral powder, sand, characterized by the fact that it is represented by the following components in their% ratio:

reclaimed crushed asphalt concrete and mineral powder formed from particles with a size not exceeding 1.25 mm of reclaimed crushed asphalt concrete, and constituting 10-20% of the amount of the latter 24-25 composite binder, in which bitumen of the first and second rows are presented as follows: bitumen of the first row - 85-95%, second row - 5-15% 4-8 oleic acid 0.2-0.6 composite reinforcing fibromaterial, in which PAN is 60-95%, basalt fiber - 5-40% 0.15-0.7 sand rest

The novelty of the proposed solution in comparison with the closest analogue lies in a non-trivial set of components, including not only groups of activating elements, but also spent reclaimed asphalt material, not only as a filler, but also as an active component, namely, a mineral powder. The latter was obtained not from traditional limestone material, but from the finest crushed particles of reclaimed asphalt concrete - a fraction with a size of no more than 1.25 mm. The difference between the proposed solution is the complete absence of crushed stone in the mixture, which is compensated by the presence of old waste asphalt, which plays the role of one of the two fillers in the mixture, the other filler (traditional) is sand.

Commercially available mineral powder, which is included in most of the applied compositions, is one of the most expensive and scarce components of asphalt concrete mixture.

EFFECT: improved physical and mechanical properties of asphalt concrete based on a new mixture composition, which contains: mineral powder, compound binder, filler in the form of sand and reclaimed asphalt concrete. For the best interaction of the listed components, which are not each in itself a new component already used in asphalt concrete mixtures, the novelty of this group of components lies in the claimed ratios of all named components and in particular the selection of a composite binder from fundamentally selected types of bitumen, which in the text of the paragraph "essence inventions "is underlined by the phrase" bitumen of the first row together with bitumen of the second row ... ".

In addition, the technical result consists in a number of advantages - an increase in moisture resistance, shear resistance, resistance to rutting, crack resistance of the resulting asphalt concrete mixture and an increase in the environmental friendliness of the environment.

The technical result is obtained by features with differences, consisting in the introduction of a surfactant component - oleic acid, in replacing crushed stone with the recommended amount of reclaimed asphalt concrete, in replacing traditional mineral powders with a new one, obtained from the reclaimed asphalt concrete of its own, as well as in new ratios of components partly used in the closest analogue.

In the course of work on obtaining the optimal claimed composition of the mixture and testing the claimed technical result, a material of asphalt concrete mixture was prepared, in which the following components appear as components:

- oleic acid complying with GOST 7580-91 produced by OOO PKF Nizhegorodkhimprodukt;

- bitumen of the Saratov oil refinery related to viscous oil road bitumen of grades BND 90/130, BND 60/90, BND 40/60, BND 200/300, BND 130/200, corresponding to the requirements of GOST 22245-90;

- basalt fiber produced by Izhbasalt LLC with a density of 54-240 tex and a cutting length of 12-18 mm, with an average chemical composition (% by weight): SiO ₂ (47.5-55.0); TiO ₂ (1.36-2.0); Al ₂ O ₃ (14.0-20.0); Fe ₂ O ₃ + FeO (5.38-13.5); MnO (0.25-0.5); MgO (3.0-8.5); CaO (7-11.0); Na2O (2.7-7.5); K ₂ O (2.5-7.5); P ₂ O ₅ (no more than 0.5); SO ₃ (no more than 0.5); other breeds (no more than 5);

- PAN fiber with a density of 0.17-0.77 tex and a cut length of 6-18 mm;

- reclaimed crushed asphalt concrete;

- mineral powder obtained from a part of the reclaimed asphalt concrete by grinding by any existing modern method, for example, in a ball mill, to a particle size of not more than 1.25 mm.

For processing the fiber was used developed in the Volga training and research center "Volgodortrans" FSBEI HE "Saratov State Technical University. Gagarina Yu.A. " a prototype of an installation for the production of composite fiber-containing asphalt concrete mixtures, which allows the preparation of fibrous materials (basalt, polyacrylonitrile and other types of fiber) for their introduction into the composition of asphalt concrete mixtures in order to reinforce and increase the physical and mechanical properties and durability of road surfaces. The plant includes a device for fluffing (splitting) fiber-reinforced fiber and a device for blowing it into the mixer of an asphalt concrete plant.

The mixing of the components was carried out under standard conditions of an asphalt concrete plant in accordance with approved technologies. Oleic acid was preliminarily introduced into bitumens of one of the grades: BND 200/300, BND 130/200 with stirring.

Example 1

In accordance with the claimed invention, an optimal composition was obtained (designated No. 1), in which the percentage of the components was as follows:

oleic acid - 0.6%;

reclaimed crushed asphalt concrete - 40%;

mineral powder formed from a part of the reclaimed asphalt concrete fraction with a particle size of not more than 1.25 mm - 20% of the reclaimed asphalt concrete contained in the composition; Calculated as a percentage of the total composition - 8%;

compound binder - 8%;

composite reinforcing fibromaterial in the composition of basalt fiber with a density of 120 tex with a cut length of 15 mm and polyacrylonitrile fiber with a density of 0.47 tex with a cut length of 12 mm - 0.7%, while basalt fiber and polyacrylonitrile fiber were taken at the following ratio of the total amount of composite reinforcing fibrous material in the mixture:

polyacrylonitrile fiber - 60%;

basalt fiber - 40%;

sand is the rest.

Composite binder - of two types of viscous oil road bitumen, in% of the total amount of binder, namely

viscous bitumen grade BND 40/60 at a temperature of 160 ° C - 95% and

viscous bitumen grade BND 130/200 at a temperature of 140 ° C - 5%.

Table 1

The composition of the applied asphalt concrete material Compressive strength, MPa, at
temperature Water resistance Shear resistance of adhesion at shear at 50 ° С, MPa Shear stability by the coefficient of internal friction Crack resistance in terms of ultimate tensile strength at fracture at 0 ° C, MPa Average speed of rutting at a temperature of 50 ° C, a wheel load of 0.6 MPa, mm / 10000 wheel passes
50 ° C 20 ° C Sample composition No. 1 8.0 2.6 0.98 0.90 0.98 7.2 0.24 Sample composition No. 2, obtained in accordance with the closest analogue (patent RU 2713015) 7.0 2.5 0.95 0.72 0.93 6.1 0.3

Table 1 shows the results of testing significant key parameters at elevated temperature (50 ° C) and low temperature (0 ° C), samples from composition No. 1 and No. 2 (the closest analogue).

It can be seen from the above results that sample No. 1 has a higher shear resistance and a lower rate of rutting at an elevated temperature, as well as a lower crack resistance at a low temperature in comparison with the closest analogue. These indicators together characterize a higher resistance to external loads in the sample obtained in accordance with the claimed invention.

Examples 2-7

The influence of the amount of oleic acid in the claimed composition on the technical result is presented. Samples of coatings of various compositions were made, for which the indicators were determined as in Table 1. The measurement results are presented in Table 2.

table 2

Composition of samples for comparative tests Reclaimed crushed asphalt concrete - 30%
Mineral powder - 10% (from reclaimed crushed asphalt concrete) or 3% from the composition of the composite material
Organic Astringent - 8%
Composite reinforcing fibromaterial of basalt fiber with a density of 120 tex with a cut length of 15 mm and polyacrylonitrile fiber with a density of 0.47 tex with a cut length of 12 mm - 0.34%
Sand is the rest
In this case, basalt fiber and polyacrylonitrile fiber with the following ratio of the total amount of reinforcing material in the mixture:
polyacrylonitrile fiber - 75%
basalt fiber - 25% The composition of an organic binder - composed of two types of road petroleum bitumen, in% of the total amount of organic binder in the mixture, the amount of oleic acid Compressive strength, MPa, at
temperature Water resistance Shear resistance of adhesion at shear at 50 ° С, MPa Shear stability by the coefficient of internal friction Crack resistance in tensile strength at cracking at 0 ° С, MPa Average speed of rutting at a temperature of 50 ° C, a wheel load of 0.6 MPa, mm / 10000 wheel passes
20 ° C 50 ° C BND 40/60 -90%
BND 130 / 200-10%
oleic acid - 0.5% 7.4 3.2 0.99 0.65 0.98 6.5 0.21 BND 60/90 -90%
BND 130 / 200-10%
oleic acid - 0.4% 7.3 3.2 0.98 0.64 0.97 6.4 0.22 BND 90 / 130-90%
BND 130 / 200-10%
oleic acid - 0.4% 7.2 3.1 0.97 0.64 0.96 6.3 0.22 BND 40/60 -90%
BND 200 / 300-10%
oleic acid - 0.3% 7.3 3.2 0.98 0.62 0.97 6.4 0.21 BND 60/90 -90%
BND 200 / 300-10%
oleic acid - 0.3% 7.2 3.1 0.97 0.62 0.96 6.3 0.22 BND 90 / 130-90%
BND 200 / 300-10%
oleic acid - 0.2% 7.2 3.1 0.97 0.61 0.96 6.2 0.22

From the given values, it can be concluded that different compositions have: high tensile strength and shear resistance, as well as a low rate of rutting at elevated temperatures and low fracture toughness at low temperatures.

These results from Table 1 and Table 2, in turn, also confirm that the claimed material has resistance to the influence of climatic factors, such as high humidity, high and low temperatures.

Claims (2)

Composition of a composite material for the manufacture of asphalt concrete pavement, including: a composite binder of one bitumen of the first row - BND 90/130, BND 60/90, BND 40/60 together with one of the bitumen of the second row - BND 200/300, BND 130/200 s the predominance of the first row of bitumen in the binder; composite reinforcing fibromaterial of polyacrylonitrile (PAN) and basalt fibers with a predominance of PAN fibers in the fibromaterial; mineral powder, sand, characterized by the fact that it is represented by the following components in their% ratio: reclaimed crushed asphalt concrete and mineral powder formed from particles with a size not exceeding 1.25 mm of reclaimed crushed asphalt concrete, and constituting 10-20% of the amount of the latter 24-25 composite binder, in which bitumen of the first and second rows are presented as follows: bitumen of the first row - 85-95%, second row - 5-15% 4-8 oleic acid 0.2-0.6 composite reinforcing fibromaterial, in which PAN is 60-95%, basalt fiber - 5-40% 0.15-0.7 sand rest