Evaluation of open-grade friction course (OGFC) mixtures with high content SBS polymer modified asphalt

Abstract

Open-graded friction course (OGFC) pavement has the benefits of removing pavement surface water, absorbing traffic noise, increasing friction resistance, etc. However, the insufficient durability restricts the service life of OGFC pavement. To settle this problem, the high content styrene-butadienestyrene (SBS) polymer modified asphalt was selected as binders in the OGFC mixture. This paper prepared four SBS modified asphalts with contents of 4.5%, 6.0%, 7.5%, and 9.0%, respectively. The Brookfield viscosity test and frequency sweep test were carried out to evaluate the rheological properties of asphalt. And the Cantabro test, indirect tensile strength ratio (TSR) test, Hamburg wheel tracking (HWT) test, and four-points beam bending (4PB) test were conducted respectively, to evaluate the raveling resistance, moisture susceptibility, rutting resistance and fatigue cracking resistance of OGFC mixture. The results showed that the addition of SBS content made the asphalt more elastic thus decreasing the sensitivity of viscosity to temperature, increasing the complex modulus as well as decreasing the phase angle. Meanwhile, the increasing SBS content also elevated the indirect tensile strength and the initial stiffness modulus and decreased the phase angle of the OGFC mixture. With the increase of SBS content, the raveling resistance, moisture susceptibility, fatigue cracking resistance and rutting resistance of OGFC mixture were entirely improved and the enhancement effect on rutting resistance at elevated temperature was more obvious. For high SBS content polymer modified asphalt, the effect of SBS content increase on the performance enhancement of the OGFC mixture progressively decreased and the SBS content of 7.5% was recommended to utilize in OGFC pavement construction.