-
Adhesion
Bitumen's adhesive properties bind together all the components without affecting their
properties in any way. A solid surface can be adhered to with bitumen in a fluid state
depending on its nature. If water is present on the surface, adhesion will be inhibited.
-
Resistance to Water
Water cannot dissolve bitumen, making this a good sealant. Bitumen is water-resistant. The
bitumen or the filler may be able to absorb water under some conditions when the inorganic
salts present in them are small.
-
Hardness
A penetration test is used to measure the hardness of bitumen. This test measures how deep a
weighted needle can penetrate in bitumen after a certain amount of time and at a known
temperature. Usually, 100g of weight is held for 5 seconds at 77° F. Permeation measures the
hardness of a material. In general, hard coating asphalt produces 10 to 20 results, roofing
asphalt 15 to 40 results, and waterproofing bitumen 100 to 200 results.
Road construction and some industrial applications use grades with penetrations greater than
40. For use in industrial applications, grades having penetrations under 40 are suitable.
Lower grades like 60/70 are typically used in hot climates.
-
Viscosity and Flow
Bitumen's viscosity is important at both high and low temperatures. Its viscosity is affected
by both the temperature at which bitumen is processed and the temperature at which it is
applied. Temperature and stress conditions influence bitumen's flow properties
significantly. Bitumen hardens as a result of deterioration or loss of its desirable
characteristics. The result is a decrease in adhesive and flow properties as well as an
increase in softening point temperature and thermal expansion coefficient.
-
Softening Point
The hardening point value should be higher than the pavement temperature for bitumen to be
used at that place. Otherwise, bitumen in the layer gets softened and comes out.
During a known rate of heating of the test assembly, the softening point is the temperature
at which a steel ball falls through the bitumen at a known distance.
-
Ductility
A ductility test applies temperature below the bitumen's softening point to determine how
much it will stretch. The temperature of 77 °F is used to test the performance of briquettes
with a cross-sectional area of 1 in2. The duality of bitumen ranges from 0 to 150.
If ductility is present, these films and coatings will form properly.
-
Specific Gravity
Binders of different densities behave the same way. In mixed design, it is still valuable.
Temperatures are set at 27o C.
-
Durability
The durability of the Bitumen refers to how long the Material will remain resistant to
oxidative hardening over long periods of time. The bitumen on the road will harden as a
result of the reaction with time.
Oxygen in the air will cause excessive hardening (poor durability) and surfacing failure,
resulting in chipping and cracking. Maintaining the asphalt properly throughout the
pavement's lifetime can extend its lifespan by as much as twenty years.
-
Versatility
As a result of its versatility property, Bitumen can be used in a wide range of applications
due to its thermoplastic properties. It can easily be spread over the underlying pavement
layers because it liquefies when heated and hardens into a solid mass when cooled.
-
Economical
It is available at cheaper rates almost all over the world which makes it feasible and
affordable in many applications.
-
Strength
Though the coarse aggregates are the main load-bearing component in a pavement, bitumen or
asphalt also play a vital role in distributing the traffic loads to the layers beneath.
