Effect of surface roughness and chemistry on ice bonding to asphalt aggregates

- An experiment was designed to study the contact bonding between ice and rock substrates.
- The effect of surface roughness and rock chemistry on the bonding between ice and rock substrates has been analysed.
- The ice bonding was higher on rough surfaces than on smoother surfaces.
- No effect of rock chemistry was found on the ability of ice to bond to the rock.

In winter maintenance, it is common to use chemicals to weaken the bonding between snow and a road. However, this practice damages the road pavement and has a negative impact on the environment. Moreover, aggregates are the main component of asphalt mixtures and, due to the wear of traffic, typically make up the surface of roads. For this reason, with the aim of reducing the need for chemicals, it is interesting to study how stone aggregates interact with ice and snow and try to evaluate if it is possible to find a type of stone which forms weak bonds with ice and snow.For the study, two rocks with different chemical compositions commonly used as aggregates on roads, granite and gabbro were selected. Rock-ice interactions were studied using an experimental setup that measured the bonding force between an ice sample and a rock substrate. Ice bonding data were analysed with respect to the type of rock and the effect of the rock surface. The results showed that the bond failure between the ice and rock was adhesive in nature, and ice bonding increases when the surface roughness increases, regardless of the chemical composition of the stone.