Performance evaluation of waterborne epoxy emulsified asphalt micro-surfacing with microwave-activated waste rubber powder

As a solid renewable resource, waste rubber powder (R) applied in road engineering can help reduce the environmental pressure caused by "black pollution" and improve pavement performance. In this research, waste rubber powder was activated by microwave method, namely as MR. The content of 0%∼ 5% MR was added as a functional filler to the waterborne epoxy emulsified asphalt (WEA) micro-surfacing mixture, thereby obtaining the MRWEA micro-surfacing. Furthermore, pavement performance, durability and noise reduction property were evaluated and compared with those of WEA micro-surfacing adding non-activated R (RWEA micro-surfacing). Results show that the surface activity of MR has been enhanced effectively, and the surface hydrophobicity of MR is better than R through the contact angle test. These findings are also confirmed by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis. Then, MRWEA micro-surfacing has good workability and cohesion due to the surface activity of MR. At the same dosage MR and R, 30 min, 60 min cohesion of MRWEA micro-surfacing mixture is greater than that of RWEA micro-surfacing mixture. Furthermore, MRWEA micro-surfacing with 3% MR has better wear resistance, rutting resistance, water resistance, durability and noise reduction properties than those of RWEA micro-surfacing with 3% R.