Effects of RH-WMA Additive on the Design Binder Content (DBC) of Warm Porous Asphalt (WPA)

Abstract Warm mix asphalt (WMA) in a pavement construction is a technology that is beneficial and contributes towards reduction of the global warming issues. In this research, WMA was used to design porous asphalt pavement with addition of organic additive which is known as RH-WMA. A Dutch modified gradation to suit Malaysian quarry practice was used to prepare the WMA. The RH-WMA additive ranges between 2 to 5 percent was added to base binder of penetration 60/70 to determine the design binder content (DBC) of the RH-WMA mix. The DBC was then determined based on the binder drainage and Cantabrian tests. The binder drainage test was used to set an upper limit while the Cantabrian test for abrasion loss was adopted to determine the lower limit of the DBC. The results for Cantabrian test indicate significant contribution of incorporating RH-WMA additive into WMA to minimize abrasion loss as compared to unmodified mixes. The binder drainage test results showed that the mixes incorporating RH-WMA additive exhibited higher drainage in varying degrees depending on the quantity of RH-WMA. The discussion was made based on target binder content, critical binder content, maximum binder content and the maximum retained binder content of the of the resulted mixes obtained from the binder drainage test.