Rheological properties and micro distribution of amorphous poly alpha olefin /styrene-butadiene rubber composite modified asphalt

Abstract

In order to improve the high temperature performance of styrene-butadiene rubber （SBR）modified asphalt, amorphous poly alpha olefin （APAO） was selected as the modifier, and APAO/SBR composites modified asphalt with good high and low temperature performance and rheological properties were prepared. The high, medium and low tempe-rature rheological properties of APAO/SBR composites modified asphalts with different amount APAO were studied. Fluorescence electron microscope was used to observe the distribution of polymers in the asphalt to reflect the rheological properties from the microscopic view. The results showed that the addition of APAO reduced the non-recoverable creep compliance and temperature sensitivity of asphalt in high temperature areas, and increased the softening point, rutting resistance factor, elastic recovery rate and fatigue fai-lure loading times of asphalt, indicating that APAO increased the high temperature performance and fatigue resistance of asphalt. Although APAO had a negative effect on the low-temperature creep stiffness modulus （S） and creep rate （m） of asphalt, the amount of APAO was not more than 5% (mass fraction, the same below) based on K （S/m）. The low temperature performance of the index was still better than that of styrene-butadiene-styrene block copolymer modified asphalt. Considering all properties, it was recommen-ded to use APAO amount of 5%, under which APAO and SBR compatibility was better.

Keywords

• styrene-butadiene rubber
• amorphous poly alpha olefin
• composite modified asphalt
• rheological property
• fluorescence microscope