Low rigidity despite high asphaltene content in bitumen: The role of resins

aggregation, which means that asphaltene molecules are arranged to form local assemblies with structural well- defined order only at short range, being higher levels of aggregations more disordered. All the data self- consistently show that the bitumen from Saudi Arabia, thanks to a higher content of resins, can stabilize more efficiently aphaltenes and therefore the latter can form ordered stacks only ad short range (only few Angstroms), leaving a more amorphous structure at longer ranges with consequently higher penetration index and lower modulus