IntelliPaper
Abstract
In this work, road petroleum bitumen was modified with styrene butadiene rubber, butyl rubber and nano-sized dolomite. As a result of the modification, the basic physical, mechanical and chemical characteristics of the resulting composition were improved. It has been shown that the penetration, softening temperature and adhesive properties of bitumen as a result of modification with polymers are improved by 1.3 times compared to standard unmodified bitumen. The use of rubbers such as butyl rubber, styrene butadiene rubber and dolomite improves the mechanical strength and adhesive properties of road bitumen. Thus, the resulting polymer bitumen is an excellent binding system for the resulting asphalt-bitumen mixture.
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I. INTRODUCTION
Petroleum road bitumen change their physical and chemical parameters in a wide range (temperature, frost resistance, ductility, elasticity, adhesive bond, resistance to aggressive environments, high dielectric strength, etc.) and, compared to their low cost, allow them to be used in various areas.
Petroleum bitumen can be used in agriculture, construction and many other industries .
The bitumen used when gluing waterproofing is a residue from the distillation of petroleum products. It is a hard-looking, black, shiny mass that, under prolonged loads, retains its ductility even at low temperatures .
Over time, during storage and under operating conditions under the influence of sunlight and oxygen, the composition and properties of bitumen change: the relative content of solid and brittle components in them increases and, accordingly, the amount of oily and resinous fractions decreases, therefore the amount of oily and resinous fractions decreases. resinous fractions. increased fragility and hardness (aging process). Therefore, the process of bitumen modification is very relevant .
The properties of bitumen can be improved by combining them with polymer additives . Currently, in the construction of roads for the production of asphalt concrete pavements, bitumen-polymer compositions are used as a binder, and for this purpose the expensive polymer thermoplastic elastomer DST-30 is used it is necessary to find more economically beneficial modifiers for road bitumen .
Typically, road petroleum bitumen has a plasticity range, as a rule, no higher than 60-65 C, which is clearly not enough for the construction of outer layers of coating in the climatic conditions of most regions. In addition, viscous road bitumen practically does not have elastic properties that determine the resistance of composite materials, such as asphalt concrete, to destruction under cyclic loading. Therefore, bitumen binders fundamentally require modification and improvement of physical and mechanical properties, since by their nature they cannot provide the necessary durability of asphalt concrete road surfaces under conditions of increasing traffic loads [17-19].
Based on a set of indicators, polymers and their waste have the greatest potential for improving the properties of bitumen binders.
nano-sized dolomite were used. The recipe and composition of the components are given in Tables 1, 2 and 3, and the physical and mechanical properties of the bitumen used are given in Table 4.
Subsequently, based on the obtained compositions, an asphalt concrete mixture was prepared using mixing equipment
II. METED AND DISSERTATION
To modify oil bitumen grades ROB 25/40, TB 70/30 and Baku 85/25, rubber, rubber waste and
Table 1: The composition of the composition based on rubber crumb (RC)
| Name of Components | No Samples | |||||
| 1 | 4 | 5 | ||||
| The content of the mass parts | ||||||
| Bitumen | 100 | 100 | 100 | 100 | 100 | |
| BR+BSR+rubber waste(2%+3%+8%)Sulfur+nano-sized dolomite | 2 | 8 | 10 | |||
| 1,5 | ||||||
| - | 1,5 | 1,5 | 1,5 | 1,5 | ||
| 2,0 | 2,0 | 2,0 | 2,0 | |||
Dolomites are a sedimentary rock that includes dolomite itself - CaCO3·MgCO3, with admixtures of clayey, ferruginous, siliceous and other substances. Dolomites come in granular, politic and crystalline structures. The hardness of dolomite is slightly higher than the hardness of limestone, its density is 2.0 - 2.8 g/cm3, and its tensile strength ranges from 120 - 300 MPa. Dolomite has a white, greenish-brown, brown and reddish-brown color. Taking into account the above, it must be assumed that it can be more effective than limestone materials when constructing structural layers of road and airfield pavements.
Different quantitative ratios of calcium carbonates in sedimentary rocks are one of the reasons for the wide variety of mineral-petrographic and physical-mechanical characteristics of these rocks, the name of which depends on the percentage of calcium carbonate in them, which is clearly shown in Table.
Table 2: Content (% by weight) of calcium carbonate in limestone and dolomite
| Name of Mineral | Standard for carbonate, in% by weight | |||||
| Pure Limestone | Dolomite Limestone | Dolomite Limestone | Calcareous Dolomite | Calcareous Dolomite | Pure Dolomite | |
| $CaCO_3$ | 90-100 | 75-95 | 50-75 | 25-50 | 5-25 | 0-5 |
| $CaCO_3 MgCO_3$ | 0-10 | 5-25 | 25-50 | 50-75 | 75-95 | 95-100 |
The mechanical properties of limestones play a significantly important role in road and airfield construction, since these properties depend on the strength and cementing ability of the carbonate rocks they contain, as well as on the presence of non-carbonate impurities, which, in each individual case, are characterized by the chemical composition of the specific limestone material.
The composition of the composition based on the components we use is given in Table 3.
Table 3: Composition of bitumen-polymer compositions
| Composition Components | The Content of Components, Mass. H. By Examples | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
| Rubber crumb+Br+BSR | - | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 |
| Bitumen | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 |
| Filler | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 |
| nanoclay+wooden stone(1+1) | 150 | - | - | - | 10 | 10 | 10 | 10 | 10 |
| The mixing temperature of the components in the mixer, °C | 100 | 70 | 90 | 100 | 160-180 | 70 | 90 | 70 | 100 |
| Mixing time, min | 15 | 10 | 12 | 15 | 65-120 | 10 | 12 | 10 | 15 |
As laboratory studies have shown, the introduction of 2 wt.% active rubber powder into grade A asphalt with good properties leads to a doubling of its softening temperature, while the frost resistance and elasticity of asphalt concrete increase.
Rubber, being an elastomeric material with a unique set of properties, only improves the durability of polymer-asphalt concrete.
In our work, the main attention was paid to improving the properties of domestic low-quality oxidized bitumen. The introduction of polymers and their waste leads to a sharp increase in the properties of Indicators of physical and mechanical properties of asphalt mixtures.
As laboratory studies have shown, the introduction of 2 wt.% active rubber powder into grade A asphalt with good properties leads to a doubling of its softening temperature, while the frost resistance and elasticity of asphalt concrete increase.
Rubber, being an elastomeric material with a unique set of properties, only improves the durability of polymer-asphalt concrete.
In our work, the main attention was paid to improving the properties of domestic low-quality oxidized bitumen.
The introduction of polymers and their waste leads to a sharp increase in the properties of bitumen (Tables 4 and 5).
Table 4: Physic-mechanical properties of a composition based on polymers and bitumen
| No | Indicators | Samples | ||||
| 1 | 2 | 3 | 4 | 5 | ||
| 1. | Penetration of a needle at 25 °C | 38 | 72 | 100 | 71 | 96 |
| 2. | Softening point, °C | 49 | 68 | 82 | 56 | 75 |
| 3. | Fragility temperature, °C | -10 | -10 | -26 | -8 | -20 |
| 4. | Tensile at 25 °C | 40 | 60 | 70 | 55 | 60 |
| 5. | Density, g/cm 3 | 2,34 | 2,36 | 2,38 | 2,2 | 2,4 |
| 6. | Temperature changes at T = 65 °C for 5 hours | 7 | 6 | 6 | 6 | 6 |
| 7. | Tensile strength at 20 °C | 2,4 | 3,0 | 3,5 | 3,1 | 3,4 |
| at 50 °C | 0,9 | 1,0 | 1,2 | 1,1 | 1,3 | |
Table 5: Indicators of physical and mechanical properties of asphalt mixtures The introduction of crumb rubber in bitumen allows to obtain a binder, which provides a significant improvement in the deformability and crack resistance of asphalt concrete.
| Indicators | Indicator Values for Examples | ||||||||
| 1 | 2 | 3 | 4 | 5 prototype | 6 | 7 | 8 | 9 | |
| Tensile strength, MPa | 4,5 | 10,0 | 6,0 | 6,5 | Breaks without load | 7,0 | 8,0 | 5,0 | 9,5 |
| Elongation at break,% | 650 | 850 | 1100 | 780 | - | 900 | 900 | 700 | 830 |
| Shore A hardness, Con, unit, усл. Ed | 63 | 50 | 35 | 58 | 20 | 45 | 43 | 40 | 45 |
| Polymer fluidity T=190 °C, P=49 H, q/10 min | 18 | 20 | 40 | 35 | 100 | 30 | 35 | 30 | 25 |
Table 6: Physical -mechanical properties of crushed stone-mastic asphalt concrete with the introduction of Thermoplastic Polyethylene on stone materials
| No | The name of indicators | Norms on Standard | 0% | 0,1% | 0,2% | 0,3% | 0,5% |
| Thermoplastic Polyethylene | |||||||
| 1. | Density (bulk density), g/cm3 | - | 2,39 | 2,40 | 2,40 | 2,41 | 2,41 |
| 2. | Residual porosity,% | 2,0–4,0 | 3,761 | 3,358 | 3,358 | 2,956 | 2,956 |
| 3. | Water saturation,% by volume | 1,5–4,0 | 2,82 | 2,33 | 2,23 | 2,16 | 2,01 |
| 4. | Tensile strength in compression, MPa at temperature: 200 °C | - | 3,29 | 3,52 | 3,67 | 4,12 | |
| 500 °C | 2,5-0,70 | 0,75 | 0,87 | 1,00 | 3,99 1,11 | 1,12 | |
| 5. | Water resistance coefficient | - | 0,86 | 0,92 | 0,94 | 0,95 | 0,97 |
| 6. | The coefficient of water resistance during prolonged water saturation (15 days.) | 0,75 | 0,79 | 0,86 | 0,88 | 0,91 | 0,92 |
| 7. | Fracture resistance - tensile strength at split at a temperature of 0 °C, MPa | 3,0 – 6,5 | 3,48 | 3,82 | 3,99 | 4,21 | 4,16 |
| 8. | Coefficient of internal friction tg | 0,94 | 0,89 | 0,90 | 0,92 | 0,92 | 0,91 |
| 9. | Shear grip at 500 °C, MPa | 0,20 | 0,18 | 0,33 | 0,57 | 0,60 | 0,65 |
| 10. | The binder runoff index,% | 0,20 | 0,24 | 0,19 | 0,18 | 0,15 | 0,13 |
Calculations of temperature stresses arising in coatings at different temperatures are given in table 8 Table 8: Temperature stresses in coatings
Table 7: Structural and rheological constants
| Coating 1 (bitumen) | Coating 2 (polymerbi Bumen) | |||||||
| $t^0,C$ | $E_{y},\text{Po}$ | $E_3,\text{Po}$ | $\theta,c$ | $\alpha_k,$ 1/degrees | $E_{y},\text{Po}$ | $E_3,\text{Po}$ | $\theta,c$ | $\alpha_k,$ 1/degrees |
| +20°C | $2,5-10^6$ | $2,18-10^6$ | $4,6-10^2$ | $4,3-10^2$ | $5,76-10^6$ | $5,02-10^6$ | $1,4-10^2$ | $2,95-10^4$ |
| +10°C | $6,3-10^6$ | $5,45-10^6$ | $11,1-10^2$ | - | $7,9-10^6$ | $6,84-10^6$ | $3,39-10^2$ | - |
| 0°C | $1,55-10^7$ | $1,15-10^7$ | $27,2-10^2$ | - | $1,41-10^7$ | $1,05-10^7$ | $8,3-10^2$ | - |
| -10°C | $3,9-10^7$ | $2,94-10^7$ | $1,51-10^3$ | - | $2,59-10^7$ | $1,95-10^7$ | $1,55-10^3$ | - |
| -20°C | $9,9-10^7$ | $2,07-10^7$ | $5,7-10^4$ | - | $3,08-10^8$ | $6,45-10^7$ | $1,74-10^3$ | - |
| Thunderstormduringrain | $6,3-10^6$ | $6,3-10^6$ | $11,1-10^2$ | - | $7,9-10^6$ | $6,84-10^6$ | $3,39-10^2$ | - |
| Stress $\sigma_t$ | $\sigma_t$ in the temperature range, Pa | |||||
| Type Covered | +20°C | +10°C | 0°C | -10°C | -20°C | Thunderstorm |
| Oil Polymer bitumen 70/30) | 4,86 | 12,24 | 27,7 | 70,24 | 90,7 | 62,5 |
| Polymer bitumen "The cream" | 5,57 | 7,62 | 12,5 | 2,14 | 43,36 | 38,17 |
: n the work, the further study was to determine the durability of the resulting polymer-phaltobitumen system. The calculation is based on assumptions under which temperature and stress change continuously, and the destruction process is irreversible according to the Bailey criterion (the principle of summation of stresses). Under the influence of various stresses, the material loses a certain amount of strength each time, and when the amount reaches unity, it collapses.
After determining the durability values of coatings at different temperatures depending on the operating stresses, the overall durability of the materials was determined using the formula
where is the percentage of days in a year with a temperature of ;
-durability of the material, respectively, at temperatures .
III. RESULT
Thus, the computational and experimental method for predicting the durability of a coating comes down to an experimental study of the properties of the coating material under various test conditions and further calculation of the durability of these coatings.
This paper presents the results of computational and experimental studies of the durability of coatings made of various materials:
Since the most common cause of destruction of asphalt concrete is the formation of cracks due to the difference in temperature deformations of the coating and the base or the coating layer and the base, Comparison of standard properties of asphalts with polymer-bitumen coating mass was reduced to determining changes in structural-rheological and physical-mechanical properties, including weather resistance and water resistance, and, as a consequence, service life and reliability. of these materials has been determined.
It has been shown that to improve the performance of highways and their durability it is necessary to modify them with polymers such as BR and BSR.
Conflict of Interest
The authors declare no conflict of interest.
Ethical Approval
Not applicable
Data Availability
The datasets used in this study are openly available at [repository link] and the source code is available on GitHub at [GitHub link].
Funding
This work did not receive any external funding.
References
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