Is a sticky,black and highly viscous liquid or semi_solid form of petroleum .it is a low grade of crude oil which is composed of complex,heavy hydrocarbons or residue distillation tower (that is called vacuum bottom).
Gravel and crushed rock are mixed with thick bitumen ,holding it together and it is then applied to road ways.
Iran has about 10% of the worlds'quality bitumen production,presently export to more than 25 countries.
-In bulk via tank vessel
-New steel drum
-Different sizes of poly bag or bitu-bag(like jumbo bag)
-Flexi tank or carbon too
It is produced by process of vacuum bottom (VB)and air in the reactor or batch due to the control of the process conditions ,different grades are produced.
The regular distillation process is discontinued at some point while the topped crude is still liquid.the heavy fraction is into a converter and air is blown through it while it is maintained at a high temperature .this process is continued until the asphalt has attaines desired properties. often ,such asphalts are called blown asphalts.
#Air blowing bitumen is divided to 3groups:
It produced by manufactured from fractional vacuum distillation of crude oil the penetration test is carried out to characterize the bitumen ,based on hardness.
As a paving grade for road construction
Based on binder specification on with a new set of tests (SHRP).and its performance at different temperatures ,in super pave grading system,binders are classified according to their performance in extreme hot and cold temperatures .PG system uses a commonset of tests to measure physical properties of the binder that can be directly related to field performance of the pavement .
PG grades nomen clature with two factors :
Traffic and pavement temperature
-in paving for both new construction and pavement rehabilitation
-in both dense-graded and open graded hot mix asphalt.
-sealing of edges of new paving and crack
-spray applications for bridge deck and -pavement protective membrane with fabrics
Is a cutback by adding controlled amounts of petroleum distillates such as kerosene. This is done to reduce the viscosity of the bitumen temporarily so it can penetrate pavements more effectively or to allow spraying at temperatures that are too cold for successful sprayed seeling with neat bitumen. The material use to cutback bitumen will evaporate after application to leave the remaining material similar in hardness to the original bitumen.
-in manufacture of pre-mix asphalt
-sprayed sealing applications (cooler weather)
_sprayed onto the primed pavement
All 3cases are according to their curing time.
Description bitumen emulsion consists of three basic ingredients:bitumen,water and an emulsifying agent ,based on specifications it may contain other additives,such as stabilizers ,coating improvers,anti-strips,or break control agents,it is well known that water and asphalt.but as the bitumen is a petroleum product it doesn't mix with water and as it is sticky in nature.
_Bitumen emulsion is divided to:
1.Anionic with negatively charged globules
2. Cationic positively charged globules
3. Non-ionic with neutral globules
_Main grades of emulsion are:
1. Rapid setting emulsion
2. Medium setting emulsion
3. Slow setting emulsion
Polymers represent the most polymers that used for modifying bitumen are(SBS/EVA/APP/LDPE/LLDE/HDPE/SBR/SEBS and SIS
SBS is one of the best modifying polymers with both thermoplastic and rubber specifications.
It is used in making pavement ,roads for heavy duty traffic and home roofing solutions to withstand extreme weather conditions,PMB is a normal bitumen with added polymers,which give it extra strength.