Laboratory evaluation of composed modified asphalt binder and mixture containing nano-silica/rock asphalt/SBS

As SBS modified asphalt has the disadvantages of high initial cost, difficult processing and poor storage stability, many researches have been conducted experiments on composed modified asphalt to get a more satisfactory pavement performance. This study proposed an asphalt mixture modified by nano-silica, rock asphalt and SBS. Basic performance tests of asphalt, rutting tests, low-temperature bending tests, moisture susceptibility tests, fatigue tests and durability tests of asphalt mixtures modified by SBS, rock asphalt, nano-silica/rock asphalt and nano-silica/rock asphalt/SBS were performed to evaluate their pavement performance. Comparing these tests results with the properties of unmodified asphalt mixture, nano-silica and rock asphalt cause an improvement in pavement performance. nano-silica/rock asphalt/SBS modified asphalt mixture had higher temperature stability, low-temperature cracking resistance, moisture susceptibility and durability than 5% SBS modified asphalt except the similar fatigue life. Furthermore, economic analysis indicated that the nano-silica/rock asphalt/SBS modified asphalt mixture had higher cost effectiveness.