Traffic generated non-exhaust particulate emissions from concrete pavement: A mass and particle size study for two-wheelers and small cars

This study aimed to understand the non-exhaust (NE) emission of particles from wear of summer tire and concrete pavement, especially for two wheelers and small cars. A fully enclosed laboratory-scale model was fabricated to simulate road tire interaction with a facility to collect particles in different sizes. A road was cast using the M-45 concrete mixture and the centrifugal casting method. It was observed that emission of large particle non exhaust emission (LPNE) as well as PM10 and PM2.5 increased with increasing load. The LPNE was 3.5 mg tire−1 km−1 for a two wheeler and 6.4 mg tire−1 km−1 for a small car. The LPNE can lead to water pollution through water run-off from the roads. The contribution of the PM10 and PM2.5 was smaller compared to the LPNE particles (less than 0.1%). About 32 percent of particle mass of PM10 was present below 1 μm. The number as well as mass size distribution for PM10 was observed to be bi-modal with peaks at 0.3 μm and 4–5 μm. The NE emissions did not show any significant trend with change in tire pressure.