FUNCTIONS AND CAPABILITIES OF ASPHALT MIXED
Asphalt functions and capabilities
Asphalt used in road pavement construction has the following functions:
- Binder, providing a strong bond between the asphalt and the aggregate and between the asphalt itself.
- Filling material, filling the voids between the aggregate grains and the existing pores of the aggregate itself.
Therefore, to be able to function as a binder and filler material, asphalt must have the ability to be resistant (not brittle) to weather, have good adhesion and cohesion and provide good elastic properties.
The description of this asphalt capability is as follows:
a. Asphalt durability.
It is the ability of asphalt to maintain its original properties due to the influence of weather during the service life of the road. This property is a property of the asphalt mixture, which depends on the nature of the aggregate covered by the asphalt, depending on the performance factor. These properties can be estimated on examination Thin Film Oven Test (TFOT).
b. Asphalt Adhesion and Cohesion.
Nature Adhesion asphalt is the ability of asphalt to bind aggregates so that a good bond is produced between aggregates and asphalt, while asphalt cohesion is the ability of asphalt to keep the aggregate in place after setting.
c. Sensitivity to temperature.
Asphalt is a material that thermoplastic, meaning it will become hard or more viscous if the temperature is reduced, and will be soft or liquid if the temperature is increased. This property is called sensitivity to temperature changes.
d. Asphalt Hardness.
Asphalt in the mixing process is heated and mixed with aggregate so that the aggregate is coated with asphalt or hot asphalt is splashed onto the surface of the aggregate that has been prepared in the smelting process. After the asphalt mixture is spread and compacted, an oxidation process occurs which will cause the asphalt to become brittle (viscosity increases), this is a brittle process. So during the service life asphalt undergoes oxidation and polymerization whose magnitude is also influenced by the thickness of the asphalt covering the aggregate. The thinner the asphalt layer, the greater the level of brittleness that occurs.
