Measurement of air permeability of stone mastik asphalt and asphalt concrete made by waste plastic pyrolysis

Due to increasing traffic volume and changing weather conditions, new methologies are being developed to prevent damage accumulation of pavements. Permeability is one of the most crucial factors affecting the performance and durability of bituminous mixtures. It is surmised that the air permeability and durability of these mixtures are linked to their void ratios. The Leeds Air Permeameter, developed at Leeds University, was introduced in this study. Note that, an air permeability test instrument was designed for the first time in Turkey (at Konya Technical University) to determine and analyze the air permeability coefficient in bituminous mixtures. Stone mastic asphalt (SMA) specimens were produced using pure and with two other waste material modified bitumen using 5% polypropylene pyrolysis and 4.5% SBS pyrolysis. In addition, asphalt concrete samples were produced using pure and two other modified bitumen using 3% and 5% plastic bag pyrolysis. The specimens were cylindrical and had diameters of 10 and 15 cm. The relationship between air permeability and void ratio of these samples has been investigated. As expected, SMA had higher void ratios and air permeability than the asphalt concrete specimens. What is more, it was observed that SMA and asphalt concrete samples with different additives produced different air permeability coefficient values within themselves. Unfortunately, a definite conclusion could not be drawn for the effect of different sample diameters on the air permeability coefficient.