In flexible pavement construction where bitumen binders are used, it is of significant importance that the binders form ductile thin films around the aggregates. This serves as a satisfactory binder in improving physical interlocking of the aggregates. The binder material, which does not possess sufficient ductility, would crack and thus provide pervious pavement surface. It has been stated by some agencies that the penetration and ductility properties, go together; but depending upon the chemical composition and the type of crude source of the bitumen, sometimes it has been observed that the above statement is incorrect. It may hence be mentioned that the bitumen may satisfy the penetration value, but may fail to satisfy the ductility requirements. Bitumen paving engineer would however want that both test requirements be satisfied in field jobs. Penetration or ductility cannot in any case replace each other. The ductility is expressed as the distance in centimeters to which a standard briquette of bitumen can be stretched before the thread cracks. The test is conducted at 27+/-0.50C and a rate of pull of 50+/-2.5 mm per minute. The test has been standardized by the ISI.
Showing posts with label construction. Show all posts
Showing posts with label construction. Show all posts
Wednesday, March 21, 2012
Sunday, March 4, 2012
OBJECTIVE OF THE MODIFICATION OF BITUMEN
A lot of efforts have been made for the modification of bitumen. But the cost of the modified binder is high because of the high price of the polymers. Considering this problem our endeavor was to use reclaimed polyethylene to fulfill the following objectives:
- To get high strength bituminous mix.
- To achieve economic goal by saving some portion of bitumen.
- To find out the changing properties of bitumen after mixing of polyethylene and kerosene.
- To sure the bituminous admixture is suitable or not for construction.
- To measure benefit from the project.
- To save the environment from pollution by using waste polyethylene.
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