RU2494988C2 - Method of producing macadam-mastic asphalt concrete - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to road construction, specifically to the technology of preparing macadam-mastic asphalt concrete mixtures for road top coats. The method of producing macadam-mastic asphalt concrete involves preparing a macadam-mastic asphalt concrete mixture by mixing dried starting materials at operating temperatures for a top coat, consisting of the following, wt %: hard rock chips - 70.0…73.5, screenings from crushing limestone M400 - 26.5…30.0; viscous bitumen - 5.6…6.0 (over 100%), characterised by that before combining with mineral components, distillation residues from producing Novantox 8 PFDA are added to the bitumen in amount of 0.5…1.2 (% of the mass of bitumen).

EFFECT: high water resistance of the material, high ultimate compression strength at +20 and +50°C, low consumption of binder in the mixture and high environmental safety as a result of recycling chemical wastes.

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Description

The invention relates to road construction, and in particular to a technology for the preparation of crushed stone-mastic asphalt mixes for the device of the upper layer of road surface coating. The aim of the present invention is to develop a method for producing crushed stone-mastic asphalt concrete with screenings of crushing limestone with improved physical and mechanical properties and reducing the consumption of binder and the cost of the device coatings using crushed stone-mastic asphalt concrete with screenings of crushing limestone (SCMA with ODI) when production and operation. EFFECT: developed method for producing alkali-alkali metal alloys with alloys with increased water resistance of the material, values of compressive strengths at +20 and + 50 ° C and environmental safety as a result of disposal of chemical industry wastes.

The closest in technical essence and the achieved result to the claimed invention is a method for producing macadam mastic asphalt mix with the addition of screenings of crushing limestone brand 400 (RF Patent No. 2426704), according to which the screening of crushing limestone brand 400 is introduced into the mineral part to the solid crushed stone.

The advantage of this method is to increase the compressive strengths of the alkali metal alloy at +20 and + 50 ° C and, accordingly, its heat resistance and water resistance coefficient and decrease in water saturation. This is achieved by converting the binder in the structure of the material into a bound (oriented) state in small fractions of ODI.

The disadvantage of the prototype is that a high tensile strength at + 50 ° C (i.e. heat resistance at high summer temperatures) of samples of crushed stone-mastic asphalt concrete mixes with additives of crushing screenings of limestones of grade 400 is achieved with an increased consumption of binder in the mixture (up to 7, 5%, in excess of 100% by weight of the mineral part).

The objective of the invention is the development of a method for improving the quality of crushed stone and mastic asphalt mixtures for the device of the top layer of road surface coating, reducing the consumption of binder in the mixture, the use of low-strength limestone crushing screenings as well as the utilization and neutralization of industrial waste.

The problem is solved in that the claimed composition of crushed stone and mastic asphalt mix with screenings of crushing limestone (ЩМА with ОДИ) is prepared by mixing dehydrated and heated to operating temperatures of the starting materials, and as a binder, a pre-prepared homogeneous mixture of viscous bitumen with waste is used chemical industry - bottoms production "Novantox 8 PFDA" (antioxidant used in the manufacture of tires) in the amount of 0.5 ... 1.2 (in% by weight).

The bottoms produced by Novantox 8 PFDA are a dark brown viscous oily liquid with a greenish or violet tint of the following composition,% wt .:

novantox 8 PFDA - 8.6;

free p-aminodiphenylamine - 0.54;

2-ethylhexanoic acid - 27.0;

K-salt of 2-ethylhexanoic acid - 9.4;

pitches - the rest.

The use of bottoms produced by Novantox 8 PFDA as a binder improves the adhesion of bitumen to mineral aggregate, which is due to the aromatic amines and resinous compounds of complex composition contained in it. The waste contains two functional groups of the opposite nature: an amino group with basic properties and a carboxyl group with acidic properties.

The mechanism of action of the additive of still residues produced by Novantox 8 PFDA in bitumen can be represented as follows: when an additive is added to bitumen, its molecules are adsorbed on dispersed particles in bitumen (on asphaltene aggregates), lowering the interfacial tension at the phase boundary of asphaltene aggregates (dispersed phase) and liquid hydrocarbons (dispersion medium). When a bitumen film is formed on the surface of mineral grains, adsorption of bitumen dispersed particles on their surface occurs. The presence of additive molecules on the surface of bitumen particles results in significantly better adhesion of the bitumen film to the surface of the stone material and increases the adhesive strength. When antioxidant resin is mixed with bitumen at a temperature of 120 ... 140 ° C, the chemical interaction of bottoms produced by Novantox 8 PFDA with high molecular weight bitumen compounds occurs, as a result, the binder is uniform.

The content of the additive for bottoms produced by Novantox 8 PFDA in the binder should be 0.5 ... 1.2%, because when the resin content is above 1.2%, the binder ductility index is outside the acceptable range due to the reduction of the softening temperature by the Ring and Ball method. Thus, the proposed differences inform the claimed object of a new technical effect, improving the adhesive properties of the binder due to the modification with the addition of bottoms produced by Novantox 8 PFDA.

The applicant is not aware of the use of bottoms additives produced by Novantox 8 PFDA to improve the adhesive properties of cementitious asphalt mixes, which indicates the compliance of the claimed object with the criterion of "inventive step".

A binder for crushed stone and mastic asphalt mix (ЩМАС) is prepared as follows:

Viscous bitumen and bottoms produced by Novantox 8 PFDA in an amount of 0.5 ... 1.2% per mixture are loaded into a device equipped with heating and a stirrer and mixing is carried out at a temperature of 120 ... 140 ° C until a homogeneous mass is obtained. The composition and properties of the binder prepared on bitumen BND 60/90 are given in table 1.

Table 1 Physical and mechanical properties Name of indicators of bitumen binder and unit of measurement Req. GOST 22245 for bitumen BND 60/90 Indicator value Ref. BND 60/90 (without additive) BND 60/90 with the addition of bottoms "Novantox 8 PFDA",% by weight of bitumen 0.5 1,0 1,5 2.0 2,5 3.0 1. The depth of penetration of the needle 0.1 mm at 25 ° C 61-90 73 71 74 78 81 86 89 at 0 ° C Not less than 20 22 21 22 22 22 24 24 2. Elongation, cm at 25 ° C Not less than 55 > 100 > 100 > 100 > 100 > 100 > 100 > 100 at 0 ° C Not less than 3,5 3.8 3.6 3,5 3,5 3,5 3,5 3,5 3. Softening temperature according to KiSh, ° C Not lower than 47 48.5 47.8 47.2 46.6 46.2 45.6 45,2 4. Fragility temperature, ° C Not higher than -15 -19 -21 -21 -21 -21 -21.2 -21 5. Clutch with marble exposure exposure exposure exposure exposure exposure exposure 6. Penetration Index from -1 to +1 -0.52 -0.93 -0.99 -1.02 -1.03 -1.05 -1.07 7. Homogeneity one but one but one but one but one but one but one but

With the proposed binder, the compositions of SCHMA with ODI of the selected composition according to GOST 31015-2003 were prepared.

The composition of ASA with ODI according to the proposed solution is as follows,% mass .: crushed stone of durable rocks 5 ... 10, or 5 ... 15, or 5 ... 20 mm - 70.0 ... 73.5; screenings of crushing limestone - 26.5 ... 30.0; viscous bitumen BND 60/90 (BND 90/130) - 5.6 ... 6.0 (in excess of 100%) and bottoms produced by Novantox 8 PFDA - 0.5 ... 1.2% by weight of bitumen.

Crushed stone mastic asphalt mixture is prepared in a commercially available stationary asphalt concrete plant equipped with a device for heating dehydration, feeding components to the mixer and mixing them.

The dosing accuracy of crushed stone and limestone crushing screenings should correspond to accuracy class 2 in accordance with GOST 10223 and GOST 30124. The dosing accuracy of bitumen and vat residues is ± 1.5% by weight.

The components of the mixture after heating to operating temperatures, dehydration and dosing, in accordance with the recipe, are mixed together at operating temperatures and the mixture is given to the consumer.

The preparation of crushed stone and mastic asphalt mixture is carried out as follows: bottoms produced by Novantox 8 PFDA heated to 50 ... 70 ° C are mixed with viscous bitumen BND 60/90 (or BND 90/130) at a temperature of 120 ... 140 ° C to obtaining a homogeneous mass, and then the resulting mixture at 130 ... 140 ° C is combined with stirring with a filler heated to 150 ... 170 ° C and other components of the mixture for the preparation of the asphalt mix.

Physicomechanical properties of the claimed composition of alkaline alkaline organic amorphous acid are presented in table 2.

table 2 Physico-mechanical properties of alkaline binder mixtures on a binder with the addition of bottom residues produced by Novantox 8 PDFA No. p / p The name of indicators Req. GOST 31015 for II-III DKZ The amount of binder in the mixture,% According to the prototype (binder without additives), 6.5 5.5 5,6 5.8 6.0 6.5 + 0.5% antioxidant resin (by weight of bitumen) one. Tensile strength at compression, MPa 50 ° C not less than 0.65 1,67 1,58 1,60 1.65 1.66 1.72 20 ° C not less than 2.2 4.73 4.41 4.00 4,50 4,54 4.68 2 Water saturation 1,0 ... 4,0 2.85 3.21 2.70 2.40 2.40 2,30 3 The porosity of the mineral part,% 15 ... 19 18.48 17.39 17.47 17.32 17.47 17.24 3. Residual porosity,% 1,5 ... 4,5 2.64 3,58 3.42 2.73 2.42 0.88 four. Water resistance coefficient not less than 0.85 0.87 0.82 0.86 0.93 0.90 0.90 5. Water saturation,% by volume 1,0 ... 4,0 2.10 3.21 2.70 2.40 2.40 2,30 6. The average density, g / cm ³ - 2.64 2.65 2.65 2.66 2.66 2.68

As can be seen from table 2, the inventive asphalt mixture SCHMAS using still bottoms produced by Novantox 8 PFDA, in comparison with the performance of the prototype samples, has higher physical and mechanical properties. The increase in the values of the coefficient of water resistance of the samples on the binder using bottoms produced by Novantox 8 PDFA is explained by an improvement in the adhesion of bitumen to the surface of mineral aggregates of alkaline alkali metal oxide. Consequently, the asphalt concrete pavement using the studied additive of bottoms produced by Novantox 8 PFDA will be more durable and waterproof.

At the same time, the use of viscous bitumen with the addition of bottoms from the chemical production of Novantox 8 PFDA allows to reduce the amount of binder by 0.7%, compared with the composition of alkaline alkaline amalgamate with ODI prepared according to the prototype for more viscous bitumen. Therefore, a reduction in the cost of preparing the mixture is achieved.

Claims (1)

A method of producing crushed stone-mastic asphalt concrete, comprising preparing crushed stone-mastic asphalt concrete mix by mixing dehydrated starting materials at operating temperatures for the device of the upper coating layer, consisting of, wt.%: Crushed stone of hard rocks 70.0 - 73.5, screenings crushing limestone brand M400 26.5-30.0; viscous bitumen 5.6 - 6.0 (in excess of 100%), characterized in that prior to combining with mineral components, bitumen residues produced by Novantox 8 PFDA in the amount of 0.5 - 1.2 (% by weight of bitumen) are previously introduced into the bitumen )