RU2784872C1 - Modified petroleum road bitumen - Google Patents

Abstract

FIELD: road construction.

SUBSTANCE: invention relates to road construction materials, namely to bitumen binders, in particular to modified petroleum road bitumen, and can be used in road construction in the process of preparing asphalt pavement. The modified bitumen includes viscous petroleum road bitumen in the amount of 99.0-99.2 wt. %, and a modifier, as which as a fat-protein concentrate “ASHER” is used in the amount of 0.8 - 1.0 wt. %.

EFFECT: improving the physical-chemical parameters of modified bitumen and the performance indicators of road pavement using this bitumen: adhesive properties to minerals of acidic and basic chemical-mineral composition, slowing down the process of thermal aging, reducing the dynamic viscosity of modified bitumen, as well as reducing the moisture saturation of the pavement and increasing the grip of the wheels of the car with the road.

1 cl, 4 tbl, 3 ex

Description

The invention relates to road building materials, namely to bituminous binders and can be used in road construction in the process of preparing asphalt pavement.

The strength of asphalt concrete road surfaces is affected by various climatic factors: temperature, water absorption, and others. Asphalt concrete is sensitive to the aquatic environment. Diffusion of water into the monolithic material occurs. The penetration of water begins with the hydrophobization of the surface due to the build-up of water molecules in it, surface sorption, which is facilitated by thermal motion (entropy factor). Water penetrates both diffusely and through the mechanism of capillary flow, since there are always micropores, microcracks of various sizes and shapes in the structure of the roadway. Therefore, the coefficient of adhesion of car tires to the road surface is of great importance.

Modified bitumen is known (RF patent No. 2 461 594, C07L95 / 00 , publ. 20.09.2012), including 0.3-0.5 wt.% amine adhesion activator, which is used as the product of the interaction of boric acid, diethanolamine and mixtures of fatty acids of vegetable oils fraction C ₆ -C ₂₀ at a molar ratio of components 1:3:(0.5-2.5).

The disadvantages of such bitumen are: a high dropping point, which leads to an increase in energy consumption for heating the product, low thermal stability, low flash point, low adhesion to roadbed materials.

The closest in technical essence is modified bitumen (RF patent No. 2 669 085, C07L95/00, publ. 06/06/2017), including 98.0-99.0 wt.% of road viscous bitumen and the rest is the condensation product of oleic acid with diethylenediamine or triethylenetetraamine with an amine number of not more than 4.5 and an acid number of not more than 20.

The disadvantages of this bitumen are: high moisture saturation, low adhesion to mineral materials and, as a result, a low coefficient of adhesion of a car tire with asphalt coating and low compressive strength.

The objective of the invention is to improve the composition of the modified bitumen, allowing to improve its performance.

The technical result consists in improving the physical and chemical parameters of the modified bitumen and the performance of the road surface using this bitumen: adhesion properties to minerals of acidic and basic chemical-mineral composition, slowing down the process of thermal aging, reducing the dynamic viscosity of the modified bitumen, as well as reducing the moisture saturation of the road surface and increase the grip of the car's wheels with the road.

The technical result is achieved by the fact that the modified oil road bitumen contains viscous oil road bitumen and a modifier, which is used as a fat-protein concentrate "USHER", in the following ratio, wt.%:

Bitumen oil road viscous 99.0 - 99.2 Fat-protein concentrate "USHER" 0.8 - 1.0

To improve the adhesive properties of bitumen to minerals of acidic and basic chemical-mineral composition, slow down the process of thermal aging, reduce dynamic viscosity, as well as reduce moisture saturation of the road surface and increase the adhesion of car wheels to the road, fat-protein concentrate (FPC) is introduced into bitumen. Due to the presence of fats and surfactants in the FPC, it mixes well with bitumen to a homogeneous mass, and contributes to a strong and complete envelopment of grains of mineral material. Adsorption processes and molecular-surface phenomena associated with the adsorption of surfactants change the structure of the boundary layers of bitumen and affect the consistency of bitumen-mineral mixtures. Carboxyl compounds are fixed on the surface of minerals in both molecular and ionic forms, which improves all the performance properties of bitumen.

FPC is obtained during the processing of vegetable oil. With alkaline neutralization of oils, a soap stock is obtained, which is treated with sulfuric acid to pH 1.5-2.0, intensively stirred at a temperature of 90°C. An aqueous emulsion is obtained, which is stratified into three phases, the middle of which is a fat-protein concentrate. ZHPK has a homogeneous viscous consistency from light brown to dark color with a density of 1004-1065kg/m ³ , non-flammable, non-toxic, non-flammable, mass fraction of total protein 15-40%, mass fraction of total fat 6-12%.

To obtain the modified bitumen, viscous oil road bitumen grade BND60/90 according to GOST 22245-90, produced by ZAO KNPZ-KEN, Krasnodar, and fat-protein concentrate produced by OAO Yugmasloprodukt, Kropotkin, Krasnodar Territory, were used.

Modified bitumen was obtained by weighing the required amount of bitumen and FPC in accordance with table 1.

Table 1

The composition of the modified bitumen

Example No. The content of components, wt.% Bitumen
BND 60/90 ZHPK The condensation product of oleic acid with
diethylenetriamine one 99.1 0.9 - 2 99.2 0.8 - 3 99.0 1.0 - 4 prototype 98.5 - 1.5

Bitumen is heated to a temperature of 150-160 ^° C, and the LPC - up to 60-70 ° C. The heated components are combined and stirred for 20-30 minutes.

The resulting modified bitumen is determined by the following quality indicators:

- adhesion to the surface of acidic and basic rocks of mineral materials was determined according to GOST 12801-98, section 28, rev.1. To determine the adhesion of modified bitumen (MB) with the surface of acidic rocks, crushed granite was used according to GOST 8267-93 of the Belorechenskoye deposit, pos. Druzhny of the Krasnodar Territory, and with the surface of the main rocks, crushed stone of the Gulkevichskoye deposit was used, x. Kievka of the Krasnodar Territory;

- penetration according to GOST 11501-78;

- softening temperature according to GOST 11508-73;

- change in mass and softening temperature after heating in accordance with GOST 18180-72 and GOST 11506-73.

Rheological tests to determine the dependence of dynamic viscosity on shear rate and temperature were carried out on a HAAKE MARS 111 rheometer in dynamic mode using a “plane-plane” measuring system with a plane diameter and a rotor of 35 mm, with a shear rate within 0-1000 s ^-1 , range melt temperature 135-163 ^o C. The working gap between the planes was taken in accordance with the thickness of the molten modified bitumen and amounted to 1 mm. The results of the quality indicators of the modified bitumen are presented in table 2.

table 2

Properties of modified bitumen

Example No. Quality indicators adhesion to mineral materials, balls Penetration, mm at
temperature, softening temperature, °C Change properties
after warming up
(5h at 163°C)
(thermal aging) Dynamic viscosity, Pa
at shear rate basic sour 25°C 0°C masses,% softening point, °C no more 100s ^-1 1000s ^-1 135 °C 163 °C 135 °С 163 °C one 5.5 5.2 91 24 49.2 0.092 9.1 0.336 0.132 0.382 0.122 2 5.5 5.2 91 24 49.2 0.093 9.2 0.332 0.132 0.385 0.125 3 5.5 5.2 92 24 49.2 0.092 9.1 0.330 0.132 0.385 0.123 prototype 5.0 5.0 90 24 47.75 0.095 9.5 0.342 0.138 0.399 0.128

Based on the modified bitumen, samples of asphalt binders were prepared, the composition of which is given in Table 3.

Table 3

Asphalt composition

Example No. Content of components, wt % mineral component modified bitumen sour
breeds main breed according to example No. 1 by prototype one 84.5 - 15.5 - 2 - 84.5 15.5 - prototype - 84.5 - 15.5

The samples were cylinders with a diameter of 50 mm, which were tested for strength and water saturation according to GOST 12248-2010 (see Table No. 4). In addition, 2 sections of the road 3 km long were asphalted (with asphalt binder according to examples No. 1 and 2), on which the adhesion force of the car tires to the road was tested. The coefficient of adhesion of tires to the road was determined by the length of the braking distance in accordance with SNiP 3.06.03-85. The results are shown in table 4.

Table 4

Asphalt quality indicators

Example No. Medium
density
g/cm ³ Moisture
saturation,
% Compressive strength, MPa at a temperature
temperature, °С Coefficient of adhesion of a car tire with an asphalt surface, points fifty 0 dry one 1.99 3.05 4.21 11.43 0.78 2 1.98 3.11 3.99 11.42 0.78 prototype 1.99 3.62 3.65 10.25 0.72

The proposed modified bitumen, compared to the known one, has higher adhesive properties to mineral materials of acidic and basic chemical-mineral composition, slows down the process of thermal aging and reduces dynamic viscosity. In addition, the moisture saturation of the road surface prepared on the basis of the proposed modified bitumen decreases from 14.1 to 15.7%, the tensile strength increases at 50°C from 9.3 to 15.3%, at 0°C from 11.4 to 11.5% and increases the grip of the car's wheels with the road by 8% in dry conditions.

However, the achievement of such indicators is possible only when using the claimed modifier and the ratio of components (see comparative examples in tables 1-4).

Claims (2)

Modified oil road bitumen, including viscous oil road bitumen and a modifier, characterized in that fat-protein concentrate "USHER" is used as a modifier, in the following ratio of components, wt.%: viscous oil road bitumen 99.0-99.2 fat-protein concentrate "USHER" 0.8-1.0.