Characteristics, mechanisms, and environmental LCA of WMA containing sasobit: An analysis perspective combing viscosity-temperature regression and interface bonding strength

Warm mix asphalt (WMA) with organic additive technology has been highly recommended in asphalt pavement. However, the viscosity-reduction mechanism, viscosity-temperature relationship, and field application effects have yet to be well excavated. Therefore, the characteristics, mechanisms, and environmental benefits of WMA containing sasobit warm agent (SWA) were developed. Kinetic viscosity, Brookfield viscosity, modified BBS tests, and rheological property tests were performed. The results showed that WMA with SWA significantly lowered the mixing and compaction temperatures. They were reduced by 38.9 °C and 36.8 °C using 4% SWA, respectively, compared with 70# base asphalt. The bonding strength between WMA and asphalt or aggregate was also improved after adding SWA. Based on the balanced performance design, the optimum SWA dosage was 3%. Measured field data showed that the asphalt fume, BSO, and benzopyrene reductions were more than 80% in WMA pavement construction adding 3% SWA. Moreover, energy consumption and carbon emissions in the LCA of WMA pavement construction adding 4% SWA were reduced by 134.86 MJ/t (21.56%) and 112.03 kg/t (40.60%), respectively. Overall, the characteristic, mechanism, and LCA analysis of WMA with SWA confirmed its great potential and application prospects.