Laboratory Research on the Properties of Warm Amorphous Poly Alpha Olefin–Modified Asphalt Mixture Using Sasobit and Deurex

Abstract

The purpose of this study was to investigate the effects of warm mix additive Sasobit and Deurex on the properties of amorphous poly alpha olefin (APAO) modified asphalt (AMB) mixture. Marshall stability (MS) and indirect tensile strength (ITS) tests were used to measure and characterize the mechanical properties of mixtures. Air voids (Va), void in mineral aggregate (VMA), and void filled with asphalt (VFA) tests were carried out to evaluate the volumetric properties. Additionally, index of retained strength (IRS), tensile strength ratio (TRS), and retained Marshall stability ratio (RMSR) were obtained by moisture damage, freeze-thaw damage, and long-term aging tests, respectively. Analysis of variance (ANOVA) was performed to verify if Sasobit and Deurex affected the mixture statistically. The results showed that the appropriate amount of warm mix additive (such as 4% Sasobit and 2% Deurex) had outstanding effects on construction temperatures and temperature sensitivity for AMB in terms of decreased viscosity and viscosity temperature susceptibility (VTS). Marshall stability tests showed that warm AMB mixture had higher carrying capacity and resistance to deformation than the control AMB mixture, and Deurex performed better than Sasobit at the same dosage. Volumetric properties tests showed that Sasobit or Deurex could increase the Va and VMA value of AMB mixtures and decrease the VFA value. Also, Deurex had more positive effects on compaction and effective asphalt ratio for the AMB mixture than Sasobit at the same dosage. The results of indirect tensile strength tests indicated that an appropriate amount of Sasobit (4%) improved the low-temperature performance of the AMB mixture, whereas Deurex had a positive effect on it. The durability test analysis concluded that the addition of Sasobit or Deurex to the AMB mixture could slightly reduce the durability of its water damage but positively affect its long-term aging performance. The statistical analysis results also confirmed that there was a significant difference in the experimental performance between different dosages of warm-mix additives. In summary, 4% Sasobit and 2% Deurex were the optimal dosages for the AMB mixture in this research concerning the construction workability, mechanical properties, volumetric properties, durability, and economic benefits.