用于高模量沥青砼的复合改性硬质沥青低温性能

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

为了寻找高温稳定性良好且具备足够低温抗裂性能的硬质沥青作为高模量沥青混凝土的胶结材料,选取SBS改性沥青对6类天然硬质沥青进行复合改性,进而对复合硬质改性沥青、沥青胶浆、沥青混合料的低温性能进行全面考察。结果表明:经过改性后,沥青、沥青胶浆、沥青混合料的低温性能有了不同程度的改善;在众多低温性能的评价指标中,沥青胶浆的低温临界开裂温度(T_(CR))与混合料低温弯曲的测试结果最具相关性,在进行高模量沥青混凝土胶结料选择时,应尤其注重对该项指标的考察。

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 (T;) 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.