Preventing of rutting and crackings in the bituminous mixtures by monoethylene and diethylene glycol based synthetic polyboron compounds

• Monoethylene and diethylene glycol based polyboron compounds were synthesized.
• Additives have been used as modifying agent for bitumen.
• The effects of additives were evaluated through conventional and superpave test methods.
• Diethylene glycol based polyboron can be used for modified bitumen in hot climates.
• Monoethylene glycol based polyboron can be used for the bitumen in cold zones.

This study deals the modification of bitumen with two new materials, monoethylene glycol based polyboron compound (MEGPC) and diethylene glycol based polyboron compound (DEGPC). These compounds were synthesized chemically and used separately as an additive within the 50/70 penetration grade bitumen. Evaluations about modified bitumens were built on the results of conventional tests (softening point test, Marshall test, Nicholson stripping test) and superpave methods (rotational viscosity, Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR)). The effects of additive concentration on the viscosity were detected at different test temperatures firstly and amount of each additive to be used in the bitumen were chosen as 2% (w/w). The softening point of the bitumen was increased by DEGPC and a slight decrease was obtained by MEGPC modifications. Marshall tests have showed that stability of the bituminous mixtures was improved by both of the additives. Better low temperature cracking resistance and stripping resistance were provided by addition of MEGPC to the original bitumen by means of BBR and Nicholson stripping test results, respectively. Rutting resistance of the original bitumen was enhanced by DEGPC modification according to the DSR test results.