ABSTRACT
Warm Mix Asphalt (WMA) technologies have become increasingly popular in recent years around the world due to their environmental benefits and advantages in energy conservation. In the present study, a laboratory investigation of the performance and chemical compositions was conducted on three WMA binders mixed with M-1, WB-2 and WB-3, respectively. The testing procedures including penetration tests, softening point tests, Rotary Viscosity (RV) tests and Fourier Transform Infrared Spectroscopy (FT-IR) analysis were performed to determine the influences of the three additives on asphalt binders. The test results indicated that the WMA additives had a significant influence on the physical performance of asphalt, such as penetration, softening point and rotary viscosity. Also, the rotary viscosity was not the single index to determine the mixing and compaction temperature of WMA binders since the WB-3 increased the viscosity. The chemical investigation conducted using FT-IR analysis showed that the effect of M-1, WB-2 and WB-3 on the asphalt may be mainly physical not chemical modification, there was no chemical bond cracking or recombination found in the FT-IR spectra. The change of the density of asphalt component may be the most effect of WMA additives on the base asphalt. By analyzing the integral spectral peak area calculation, the change trend between the area ratio of the aromatics base absorption peak to rotary viscosity was found the same, which could be due to the fact that the aromatics has impact on the rotary viscosity directly in the three WMAs.
