Research data on pavement particle retention for D6.5

We tested the hypothesis that porous asphalt would be able to retain more dust (including microplastics) in its pore network than conventional dense asphalt. Hence, the collection of pore dust was done on the four sections of the carousel to compare among pavements and according to the number of cycles. This is because the different sections will experience the same weather conditions, such as precipitation, wind speeds or dust deposits. Dust was collected each time the carousel stopped (at 0, 20,000, 50,000, 100,000, 200,000, 500,000, 750,000 and 1,000,000 cycles) using a specially designed vacuum cleaner. This equipment was used thanks to a collaboration with CSIC. Based on the laboratory results, this equipment is able to recover the particles not only on the surface but also those inside accessible pores. The area vacuumed per section was initially 30 x 5 cm2, then 30 x 15 cm2 to increase the sample size. Samples were collected both in the wheel track area and in an outer ring separated from the circulated zone. The samples are weighted and referenced to the sampling area. Collected dust samples were stored in individual containers and sent to the laboratory of the UC to process them by thermogravimetric analysis (TGA) and SEM for their microplastics contents.