An Overall Review: Modified Asphalt Binder Containing Sasobit in Warm-Mix Asphalt Technology

Abstract

Increasing emission of greenhouse gases is an environmental issue, and it is a great concern to curb this problem from further harm to the environment. Warm-mix asphalt (WMA) is one of efforts to curb a reduction in the temperature at which asphalt mixes are produced. WMA can reduce the temperature to 100°C and even lower without compromising the performance of asphalt binder. WMA has various benefits such as, reduction of asphalt binder temperature, reduction in energy consumption and less air pollution. It reduces short-term aging, compacting effort and decreases temperature drop during transportation. Sasobit is one of the organic additives of warm mix asphalt. It is used as a binder modifier to produce rut resistant mixtures. It provides the option of reducing fume emissions, saving energy and reducing production cycles. Therefore, sasobit is the preferred additive for warm-mix asphalt (WMA). In addition, Complex shear modulus will be determined to find the rutting factor and fatigue factor for the asphalt binder (G*/Sinδ and G*Sinδ respectively). The overall purposes of this study are to determine the importance of using WMA as a green pavement and introducing sasobit for modifying virgin asphalt binder.

Improving the Temperature Sensitivity of Bitumen for Emergency Pavement Repair

“…Varying the wax concentration was shown to influence the penetration and softening point of the binder as well as the PI in a similar way to varying the rubber content. The explanation for this might be that when the wax cools and crystallizes it forms a uniform network structure in the modified binder [14]. Furthermore, at temperatures under 100 °C, wax seemingly forms a crystalline lattice structure in the binder that results in increased rutting resistance at service temperatures leading to more stability [17].…”

“…Hence, transportation and temperature can be considered very important factors because they impact on the performance of the pavement. Therefore, adding wax to rubberized binder may tackle this problem which reduce the temperature construction and improve the temperature sensitivity of binder [14,15]. Wax (Sasobit®) is an additive to bitumen to improve its workability and durability.…”

“…At temperatures under 100 °C, Sasobit® seemingly forms a structure of crystalline lattice in the binder that results in increased rutting resistance at service temperatures leading to improved stability [17]. Furthermore, Sasobit® plays as a flow-improver reducing the binder viscosity and thus enabling lower mixing and compacting temperatures [14]. Recent studies have demonstrated that adding 1%-3% of Sasobit® to the asphalt binder lowers the binder viscosity, making it easier to be mixed and handled at lower temperatures compared with unmodified asphalt binder [18].…”

A Review on Improving Asphalt Pavement Service Life Using Gilsonite-Modified Bitumen

“…However, there is a negative effect that needs to be considered; the SBR increased the temperature sensitivity for gilsonite-modified asphalt binder [39]. However, it is interesting to note that adding wax improved the temperature sensitivity of asphalt binder [46][47][48] and can overcome this problem.…”

“…Once the amount of gilsonite that increased the mixing temperature and compaction temperature had been determined [31] (thus, avoiding this negative impact of gilsonite), Sasobit was nominated to modify the asphalt binder accompanied by gilsonite [42]. Sasobit has been used in practice mostly to decrease the construction temperatures (mixing and compaction temperatures) of asphalt modified mixture [46][47][48]. However, Sasobit has a negative effect on the moisture sensitivity of asphalt mixtures [42].…”