Blown bitumen grades:
Blown bitumen grades (115/15 90/40 90/10 90/15 85/25 105/30 150/5 75/25) have wide range of usages. It uses in where there is expected minimum amount of moving in the joint. Their wide temperature range prevents bleeding in high temperature. It can also apply in industrial like roofing, flooring, mastic, pipe coatings, electrical usages.
- Oxidized Bitumen is a peculiar amorphous material which is generally in liquid form when discharged by oxidation plants at a temperature ranging from 240°-300° C., and becomes solid or pasty at ambient temperatures.
- While being relatively hot, it is viscous, whereas when in pasty or solid state it possesses a fair degree of elasticity. Both in liquid and in plastic or solid form oxidized bitumen is a highly insulating material with good adhesion properties with respect to almost any solid material.
- An exothermic oxidation reaction occurs, yielding asphalt that is harder, more viscous, less volatile, and less temperature-susceptible than the asphalt flux used as the feedstock to the process.
- Asphalt, oxidized (blown or air-refined): Asphalt treated by blowing air through it at elevated temperatures to produce physical properties required for the industrial use of the final product.
Blown Asphalt Explain
This process is continued until the asphalt has attained desired properties. However, this is not strictly a true term because not only oxidation but also vaporization, Dehydrogenation, condensation, polymerization and other reactions occur during the air blowing process.
Blown Asphalt Feature
One of the most significant properties of air-blown asphalt is that the temperature at which asphalt becomes soft is raised. This temperature is usually called the softening point of asphalt. Even at this temperature asphalt still retains its waterproofs and durability. However, there is some reduction in -ductility as compared with asphalt cement for paving purposes.
Blown Asphalt Uses
The users usually use Blown asphalts for a wide variety of industrial and specialty purposes. Just a few of these are: a variety of roofing applications, pipe coating enamels, underselling asphalts to sill cavities beneath Portland cement concrete pavements, and waterproof membranes for lining canals and reservoirs.