Evaluation of mechanical and physical surface properties of polymer modified porous asphalt containing rubber powder

Porous asphalt pavement (PA) material is a special open-graded asphalt mixture which has a large proportion of interconnected air voids with a void content of 18% or more. Traffic noise, splash, spatter, aquaplaning and skid resistance are public problems in dense asphalts. Porous asphalt pavement is an alternative that believed to be meeting above mentioned requirements. The aim of this study is to evaluate the performance of rubber powder and styrene-butadiene-styrene (SBS) on mechanical properties, surface friction, macrotexture and sound absorption of these PA mixtures. For this purpose, Porous asphalt mixtures with two different types of gradation were studied and compared. SBS polymer and recycled rubber powder were used to modify 60/70 bitumen. In order to evaluate the desired characteristics, ITS moisture sensitivity, Cantabro abrasion, Drain down, pavement macrotexture depth, British pendulum and sound absorption tests were carried out on the specimens. Test results showed that rubber powder had a positive effect on surface friction and a negative effect on sound absorption of polymeric PA mixtures. However, the gradation containing more fine aggregates had a better surface friction than the other one. In addition, adding crumb rubber into polymeric porous asphalt mixtures, decreased sound absorption in all frequencies from 125 to 1250 Hz.