Low⁃temperature performance of composite modified hard asphalt used in high modulus asphalt concrete

To find hard asphalts with perfect high temperature stability and low temperature crack resistance as the cementation material of high-modulus asphalt concrete, SBS modified asphalt was used to modify six kinds of natural hard asphalt. The relationship between the dosage of SBS and the dynamic modulus of the mixture was explored. The low-temperature performance of this hard asphalt before and after the modification was investigated from the three levels including asphalt, asphalt mortar and asphalt mixture. The results show that the low temperature performances of the modified asphalt, asphalt mortar, and mixture also have different degrees improvements. It is a good choice for producing high-modulus asphalt concrete. The study also found that among the many low-temperature performance evaluation indicators, low-temperature critical cracking temperature (TCR) of asphalt mortar is the most relevant to the test results of low-temperature bending of the mixture. When selecting asphalt binder for high-modulus asphalt concrete, special attention should be paid to this indicator. © 2022, Jilin University Press. All right reserved.