RU2515277C1 - Mineral powder for asphalt concrete mixture - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to road construction and particularly to production of mineral powder for an asphalt concrete mixture. The mineral powder for an asphalt-concrete mixture contains a surfactant, a water repellent agent and a mineral component, the mineral component being carbonate rock powder, the surfactant being a product of treating soap stock by acid-catalysed hydrolysis with an acid number of 100-140 units and the water repellent agent being heavy vacuum tar, with the following ratio of components, wt %: product of treating soap stock 0.7-1.8, heavy vacuum tar 1.0-1.6, mineral component - the balance.

EFFECT: improved water-repellent property of the mineral powder, reduced swelling of the powder and high ultimate strength of the asphalt concrete based thereon.

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Description

The invention relates to road construction, in particular to the production of mineral powder for asphalt mixes.

Known mineral powder for the asphalt mixture, the activating mixture to obtain which, in addition to bitumen and anionic surfactant (APA), contains distillation residue of caprolactam distillation in an amount of 2.5-5% by weight. As a surfactant used: second fat tar, synthetic fatty acids, bottoms of synthetic fatty acids or gossypol resin (RU 2112759 C1, C04B 26/26, 06/10/1998).

A disadvantage of the known mineral powder is that the use of a highly polar and partially water-soluble distillation residue of caprolactam containing up to 80% sodium salt of aminocaproic acid can lead to excessive water saturation of the mineral powder in the composition of asphalt concrete during long-term operation of the road surface, and data on tests of the obtained asphalt concrete after long period of operation are absent.

Known activated mineral powder for the asphalt mixture, including the mineral material of carbonate rocks, the second fat tar and soluble wood resin in the following ratio of components, wt.%: Mineral material 97.8-98.2; second fat tar 0.5-1.3; soluble wood resin 0.9-1.3 (RU 2120922 C1, C04B 26/26, C04B 20/10, 10.27.1998).

The disadvantages of this composition include the fact that the additive used - soluble wood resin, is characterized by an unstable chemical composition, which complicates the observance of technological conditions when activating mineral powder. In addition, soluble wood resin contains strong organic acids, which destroy the particles of mineral powder from carbonate species, which contributes to increased water absorption of the pavement and its destruction.

Known activated mineral powder for the asphalt mixture, comprising as an activating mixture a bitumen-rubber binder and a surfactant with a ratio of components, wt.%: Bitumen-rubber binder 1.0-3.0; Surfactant 1.0-1.1; mineral powder - the rest is up to 100 (RU 2160238 C1, C04B 26/26, 12/14/1999).

A disadvantage of the known composition is that the bitumen-rubber binder used is an under-oxidized compounding compound of rubber and bitumen, which means it is subject to oxidative aging processes, which affects the reduction of its durability in operating conditions.

The closest to the claimed invention in terms of features is a mineral powder for an asphalt mixture, including a surfactant, a water repellent and a mineral component containing, as a surfactant, the residue from production of alkyl sulfate (OAC), as a hydrophobizator, heavy tar, and as the mineral component is crushed marble or limestone (fraction 0.01-0.1 mm) in the following ratio of components, wt.%: OSA - 0.8-1.5; heavy tar - 1.0-2.0; mineral component - the rest is up to 100. The remainder of the production of alkyl sulfate (OAS) is formed in the production of household synthetic detergents when the commercial product is isolated after neutralization of the sulfated technical mixture of higher alcohols and is a mixture of anionic and nonionic surfactants and contains, wt.%: alkyl sulfates sodium - 77-86; higher alcohols (C10-C16) - 6-9; paraffins (C10-C16) - 8-14 (RU 2125547 C1, C04B 26/26, C08L 95/00, 01/27/1999), adopted as a prototype.

The reasons that impede the achievement of the technical result indicated below when using a known composition of mineral powder include the fact that the detergent production waste containing up to 23 wt.% Paraffins and higher alcohols, which although contribute to the hydrophobization of mineral powder, but reduce its adhesive properties. In addition, sodium alkyl sulfates can undergo thermal decomposition under conditions of mixing of asphalt concrete, for example, local overheating, which leads to their loss of surface-active properties and a decrease in the strength of the final asphalt concrete. To clarify these shortcomings, a broader study of the physicomechanical properties of asphalt concrete is necessary, including under extreme conditions.

The technical result is an increase in the hydrophobicity of the mineral powder, a decrease in the swelling of the powder and an increase in the tensile strength of asphalt concrete based on it.

The specified technical result in the implementation of the invention is achieved by the fact that in the known mineral powder for the asphalt mixture, including a surfactant, water repellent and a mineral component, the feature is that the mineral powder contains carbonate rock flour as a mineral component, and surface -active substance is a product of soap stock processing by acid-catalyzed hydrolysis with an acid number of from 100 to 140 units and heavy vacuum tar as a . Drofobizatora at a ratio of components, wt%:

soap stock processing product - 0.7-1.8;

heavy vacuum tar - 1.0-1.6;

mineral component - the rest is up to 100.

Information confirming the possibility of carrying out the invention with obtaining the above technical result was obtained during the testing of a method for producing a mineral powder for asphalt concrete mix from heavy vacuum tar obtained by treating old oil-containing waste - oil sludge from storage barns, a product of processing stock and flour of carbonate rocks (limestone, dolomite, marble) according to GOST 14050-93.

Mineral powder for the asphalt mix is prepared as follows.

Heavy vacuum tar is obtained from oily waste. To do this, long-standing oily waste from the sludge storage tanks is prepared by dehydration to a water content of not more than 5 wt.% And separation of the mineral component to a content of solids of not more than 16.4 wt.%, By any known methods. Then the raw material is heated at a pressure of 8-10 mm Hg and a temperature of 215-350 ° C in an atmosphere of inert gas (nitrogen, argon or carbon dioxide), and a heavy vacuum tar is obtained with simultaneous distillation of light and dark oil products. Fractions of light and dark oil products are used as a diluent for the feedstock or as lubricating fluids in the production of asphalt concrete or mineral powder. Mineral powder, the composition of which is shown in table 1, and the asphalt mixture is prepared according to conventional technology. The results of the analysis of asphalt concrete obtained with the use of mineral powder produced by the proposed method (see table 2), prove its compliance with the requirements for asphalt mixtures with regulatory documents.

The use of long-standing oily waste from accumulative barns as a feedstock for bitumen makes it possible to obtain a heavy vacuum tar different in properties from tar obtained from standard oil raw materials. This is due to the fact that long-term storage in storage ponds of long-standing oily waste is exposed to microorganisms and atmospheric oxygen, as a result of which oxidation and biodegradation products accumulate that increase the adhesive properties of the corresponding tar. A deep selection of normal paraffins during vacuum processing of raw materials improves the adhesion of tar to carbonate rocks.

As a surfactant in the proposed method, a soap stock processing product is used, which is obtained by acid-catalyzed hydrolysis of the waste from the refining process of vegetable oils, soap stock, to reach an acid value in the range of 100-140 mg of potassium hydroxide per gram of product. Such a product does not comply with GOST 7580-91 and has limited use. However, according to (BCH 59-68 “Instructions for the use of surface-active substances in the construction of pavements using bitumen” // Approved by the Ministry of Transport of the USSR 07/02/1968) anionic substances such as higher carboxylic acids must have an acid number of not less than 50 mg potassium hydroxide per gram of product.

Table 1 Comparative results of the analysis of the proposed and known mineral powder Mineral Powder Components The composition of the mineral powder, mass. % Proposed Famous one 2 3 one four 7 APAV 0.7 1.3 1.8 0.6 1,2 1.7 Heavy tar 1,6 1.3 1,0 2.2 1,5 0.8 Mineral component 97.7 97.4 97.2 97.2 97.3 97.5 Properties:
Swelling *,% volume
Bitumen rate, g 1,2
45.6 1,5
47.2 1,6
48.3 1.4
54.9 1.4
47.7 2.5
49.0 Hydrophobicity Hydrophobic Weakly hydrophobic

* Properties according to GOST R 52129-2003

table 2 Comparative results of the analysis of standard asphalt concrete and obtained using the proposed and well-known mineral powder Asphalt Parameters Indicator Received using the proposed min. powder * Obtained using a known min. powder Standard ** Regulatory Requirements *** The average density, g / cm ³ 2,55 - 2,52 - Water saturation, W,% 3.84 - 1.80 1.5-4.0 Strength, MPa: at 20 ° С 3.73 3.60 4.80 Not less than 2.5 at 50 ° C 1.36 - 2.20 Not less than 1.2 at 0 ° С 8.95 - 8.20 Not less than 11 split tensile 4.30 - 5.30 3,5-6,0 Coefficient of internal friction 0.87 - 0.94 Not less than 0.81 Shear grip at 50 ° C, MPa 0.43 - 0.45 Not less than 0.37 Water resistance 0.96 one 0.90 Not less than 0.9 Water resistance with prolonged water saturation 0.89 - 0.94 Not less than 0.85 The porosity of the mineral part,% 16.17 - 16,20 14-19 Residual porosity,% 2.75 - 2.90 2.5-5.0 * Mineral part - dolomite flour, water repellent agent - heavy tar, surfactant - product of soap stock processing.
** Standard asphalt concrete based on road bitumen BDN 90/130 according to GOST 22245-90 and mineral powder MP-1 according to GOST R 52129-2003.
*** Dense type I asphalt concrete mix of grade I for III road-climatic zone in accordance with GOST 9128-2009.

Claims (1)

Mineral powder for an asphalt mix, including a surfactant, a water repellent and a mineral component, characterized in that the mineral powder contains carbonate rock flour as a mineral component, and the product of soap stock processing is acid-catalyzed hydrolysis with an acid number of 100 to 140 units and a heavy vacuum tar as a water repellent, with a ratio of components, wt.%:
soap stock processing product - 0.7-1.8;
heavy vacuum tar - 1.0-1.6;
mineral component - the rest is up to 100.