Thermoreversible aging in model asphalt binders

Abstract Thermoreversible aging is an important factor leading to premature cracking in asphalt pavement. In order to better understant the contribution of various pure waxes in asphalt binder to thermoreversible aging, model asphalts are prepared with three kinds of alkanes (eicosane, triacontane, and squalane). The effects of alkane dopant crystallization on the thermoreversible aging properites of low- and high-wax asphalts are examined using extended bending beam rheometer (ExBBR) test and limiting phase angle temperatures. The results show that eicosane is an additive that improves the conventional 1 h low-temperature performance of asphalt binder, but it will aggravate the thermoreversible aging and the magnitude depends on the base asphalt and concentration of additive. The branching of straight-chain hydrocarbons can improve the low-temperature performance of the corresponding asphalt without aggravating the degree of thermoreversible aging. Limiting phase angle temperature is more sensitive to the dosage of C30 and squalane additives. But poor correlation is found for C20 doped asphalts.