Characteristics of asphalt
Analytical design of asphalt pavement includes considering two aspects of material properties:
1. Characteristics of loading, deformation or stress and pressure used to analyze critical stresses and pressures in the structure.
2. Performance characteristics of materials that show the state or states of failure.
Two basic principles are cracking and deformation of asphalt. The first case is used to bind materials in the pavement of sidewalks, while the second case is used for all pavement materials, both hard and flexible.
As mentioned earlier, asphalt behaves viscoelastically. (both in elastic and viscous state) which has a ratio of each depending on the loading time and the temperature at which it is loaded.
The complexity of this behavior increases depending on the ratio of the components in the mixture, and bitumen is responsible for viscoelastic properties, while mineral structure affects elastic and plastic properties.
The components and compositions of mixtures can be very diverse, which makes it difficult to predict the properties of a particular mixture.
Asphalt hardness can be divided into two parts:
• Elastic hardness under low temperature or short loading time.
• Viscous hardness under high temperature and long loading time.
The first case is used to calculate the critical pressures in the analytical design structure, while the second case is used to evaluate the material's resistance to deformation. It has also been shown that at moderate temperatures when stiffness is both elastic and viscous it is stress dependent.
High stresses lead to lower hardness and low stresses lead to higher hardness and make it difficult to evaluate the performance. Although the stress dependence is less important than the effect of loading time and temperature.
Hardness at a certain temperature and time can be measured in several ways:
- Bending or vibration test on the sample
- Direct uniaxial or triaxial tests on cylindrical samples
- Indirect tensile tests on cylindrical samples
- Dynamic loading on asphalt mixture performance test
Identical samples of the same mixture will return different modulus values because the results depend on the measurement factors.
Various types of loading can be used in the test, but for the elastic stiffness of materials carrying repeated traffic, sinusoidal or quasi-sinusoidal loading at high frequency, they are most suitable.
Prediction of asphalt hardness:
Asphalt hardness can be easily measured using tests such as the indirect tensile modulus test, although when testing is not possible the hardness of a particular mixture can be determined experimentally with acceptable accuracy at any temperature and at any loading time. evaluated
In order to determine the deformation characteristics of asphalt, the low stiffness response of the material (at high temperature and loading time) should be analyzed. When the bitumen hardness is less than 0.5 MPa, the behavior of the mixture is much more complicated than when it is in the elastic region. (It means the region where the elastic behavior of the mixture is more prominent than the viscous state)
Under these conditions, the hardness of the mixture depends not only on the hardness of the bitumen and the voids in the rock and bitumen mixture, but also on other factors such as the percentage of bitumen, shape, texture, degree of blockage and degree of compaction.
Asphalt with bitumen 60 70 and bitumen 80/100 are two commonly used asphalt mixtures with different characteristics. Here are some key characteristics of each:
- Penetration: Bitumen 60 70 has a penetration value between 60 and 70 decimeters, which indicates its consistency or hardness. It is relatively softer compared to other bitumen grades.
- Viscosity: It exhibits moderate viscosity, which affects its flow and workability during mixing and placement.
- Temperature susceptibility: Bitumen 60/70 has a moderate temperature susceptibility, meaning it can handle a range of temperature variations without significant changes in its properties.
- Performance: Asphalt with bitumen 60/70 offers good resistance to rutting and deformation, making it suitable for areas with moderate traffic loads and moderate to high ambient temperatures.
- Applications: It is commonly used in asphalt pavements for highways, urban roads, airport runways, and other similar applications.
- Penetration: Bitumen 80/100 has a penetration value between 80 and 100 decimeters, indicating it is harder and less penetrable compared to bitumen 60/70.
- Viscosity: It exhibits higher viscosity than bitumen 60/70, which affects its workability during mixing and placement.
- Temperature susceptibility: Bitumen 80/100 has lower temperature susceptibility, meaning it is less affected by temperature changes compared to softer grades.
- Performance: Asphalt with bitumen 80/100 provides improved resistance to rutting, deformation, and thermal cracking. It is suitable for areas with higher traffic loads and a wider range of temperatures.
- Applications: It is commonly used in asphalt mixtures for heavy-duty pavements, such as highways, ports, industrial areas, and areas with high traffic volumes.
It's important to note that the specific characteristics of asphalt mixtures with bitumen 60/70 or bitumen 80/100 can also be modified by incorporating additives or modifiers to meet specific project requirements. These modifications can enhance performance, durability, and other desired properties of the asphalt.
ATDM CO is a reputable manufacturer and exporter of Bitumen 60/70. We specialize in offering high-quality bitumen products in various packaging options, including drums, bags, and bulk quantities. Our product line consists of three distinct quality grades: premium, second, and third types. Each grade is produced with meticulous attention to detail, utilizing advanced facilities and processes.
Our diverse range of options is designed to cater to the specific needs and volume requirements of our customers. Whether you require a smaller quantity for a specific project or a larger bulk order, we have the flexibility to accommodate your demands.
At ATDM CO, we prioritize product quality, reliability, and customer satisfaction. Our bitumen 60/70 is manufactured to meet international standards, ensuring optimal performance and durability in various applications. Currently, we have supplies in three countries of the United Arab Emirates (Dubai), Panama and Singapore are available. We take pride in delivering exceptional products that meet the diverse needs of our valued customers, both domestically and internationally.
