RU2378209C1 - Composition of binder for preparation of asphaltic bitumen mixture - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention is related to compositions of binding material for preparation of asphaltic bitumen mixes and may be used in erection, reconstruction and repair of transport structures with hard surface. Composition of binder for asphaltic bitumen pavements, including the following components, wt %: bitumen 41-43, Sulfur 54-56, mineral oil 2.1-2.35, lime 0.1-0.6, hydroxide of trivalent iron 0.2-0.5, carboxymethylcellulose 0.02-0.03, polymer 0.02-0.08. Composition provides for increase of surface softening temperature by 5-11°C, reduction of brittleness temperature by 4-7°C, increased strength and service life.

EFFECT: increased temperature of asphaltic concrete softening temperature, reduced temperature of its brittleness and, as a result, increased service life, and also elimination of ecological and corrosion problems.

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Description

The invention relates to compositions of cementitious material for the preparation of bitumen-asphalt mixtures and can be used in the construction, reconstruction and repair of transport structures with hard surface.

A known asphalt-bitumen mixture containing, in addition to the mineral filler, an astringent composition consisting of bitumen, sulfur and mineral powder (US Pat. SU No. 1270140 A1, C04B 26/26, 11/15/1986) (1).

Asphalt-bitumen coatings made using such mixtures have a number of disadvantages, namely, unsatisfactory strength characteristics, a narrow range of operating temperatures and a limited lifetime.

Closest to the invention is an astringent composition containing bitumen, industrial sulfur, mineral oil and lime, in the following ratio of components, wt.%:

Bitumen 40-42 Elemental sulfur 53-55 Mineral oil 2.7-3.0 Lime 0.2-0.6

(application RU No. 2004113163/03, С04В 26/26, publ. October 27, 2005) - prototype (2).

The disadvantage of the prototype are not high enough qualities of the asphalt coating, namely:

- insufficiently high softening point (50-52) ° С;

- not enough low temperature of fragility minus (13-14) ° С;

- insufficient strength characteristics;

- environmental and corrosion problems due to the fact that in the manufacture of asphalt mixtures at a temperature of 140-160 ° C, sulfur is restored by removing hydrogen from hydrocarbon compounds with the release of hydrogen sulfide, and in the presence of air it is oxidized with the release of sulfur oxides. Hydrogen sulfide and sulfur oxides are toxic and corrosive chemicals.

An object of the invention is to increase the softening temperature of asphalt concrete, lower its brittleness temperature and, as a result, increase its service life, as well as eliminate environmental and corrosion problems.

The stated technical problem is solved in that in the composition of the binder for an asphalt-bitumen mixture containing bitumen, elemental sulfur, mineral oil and lime, the new is that it additionally contains iron hydroxide, CMC and polymer in the following ratio of components, wt.%:

Bitumen 41-43 Sulfur 54-56 Mineral oil 2.1-2.35 Lime 0.1-0.6 Ferric hydroxide 0.2-0.5 CMC 0.02-0.03 Polymer 0.02-0.08

The invention consists in the following:

- the addition of ferric hydroxide Fe (OH) ₃ , which is an adsorbent of sulfur dioxide, reduces the release of the latter during the preparation and paving of asphalt and at the same time reduces the corrosiveness to technological equipment, increases strength characteristics and improves the environmental situation;

- ferric hydroxide is simultaneously a highly effective emulsifier of colloidal systems (emulsions, suspensions) and at the same time creates stable colloidal sulfur-bitumen systems, which improves the strength characteristics of asphalt-bitumen compositions;

- the addition of CMC (an organic alkali metal salt) and a polymer that act as plasticizers in the mixture improves the physicochemical and mechanical properties, mainly the extensibility of the asphalt mix, which provides an increase in softening temperature and lower brittleness temperature, while CMC and polymer are additional emulsifiers that prevent the loss of sulfur at high temperatures.

The proposed composition is prepared as follows.

Bitumen at a temperature of 140-160 ° C is mixed with mineral oil, which can be used as transformer or machine oil, including worked out. Separately, sulfur is mixed with pre-soaked CMC and crushed polymer, in particular rubber powder, PAA or others, and then with lime and ferric hydroxide, after which the mixture is heated with stirring to a temperature of 130-150 ° C until a homogeneous liquid suspension is obtained. Then both mixtures are mixed at a temperature of 140-150 ° C until a homogeneous suspension.

Table 1 shows examples of the preparation of compositions A, B, C according to the invention and composition G of the prototype.

Table 1 Name of components Amount, wt.% BUT B AT G (prototype) Bitumen 43 42 41 42 Elemental sulfur 54 55 56 55 Mineral oil 2.1 2.2 2,35 2.75 Lime 0.6 0.35 0.1 0.25 Ferric hydroxide 0.2 0.4 0.5 - CMC 0.02 0.01 0,03 - Polymer 0.08 0.04 0.02 -

To prepare the asphalt-bitumen mixture, the prepared binder composition is mixed with mineral fillers (for example, crushed stone, sand, etc.) at a temperature of 140-150 ° C.

Table 2 shows the physico-chemical and mechanical properties of the asphalt mix in the same examples A, B, C and D, as well as the requirements according to GOST 22245-90.

table 2 Indicators Examples GOST 22245-90 BUT B AT G (prototype) Softening point, ° С ≥47 54 56 58 52 Fragility temperature, ° С ≤-15 -19 -21 -twenty -fourteen Tensile at T = 25 ° C, cm ≥55 60 63 62 54

Thus, the proposed binder composition provides the asphalt concrete coating with high plasticity (extensibility), increases the softening temperature, lowers the brittleness temperature, as a result of which the strength and service life of the coating are increased by more than 2 times at a temperature of 50 ° C or more.

An additional effect of the invention is that the material is practically not susceptible to plastic deformation, even in places of stops and following heavy vehicles. In addition, it is more resistant to motor oils due to a decrease in the percentage of bitumen in the composition and the formation of a stable complex colloidal system.

Claims (1)

The composition of the binder for the preparation of the asphalt-bitumen mixture containing bitumen, elemental sulfur, mineral oil and lime, characterized in that it additionally contains iron hydroxide, CMC and polymer with a ratio of components, wt.%:
Bitumen 41-43 Sulfur 54-56 Mineral oil 2.1-2.35 Lime 0.1-0.6 Ferric hydroxide 0.2-0.5 CMC 0.02-0.03 Polymer 0.02-0.08