Impact Load Test to Measure the Cohesion Energy of Asphalt Binders

The cohesion of asphalt binder plays a pivotal and effective role in evaluating the performance efficiency of asphalt mixtures under different loading and environmental conditions. This cohesion can be represented by the forces that bind the asphalt particles to each other (the structural form of asphalt particle bonding). The amount of force that causes the displacement of these particles to the point of fracture is equal to the ability of the cohesive asphalt binder to prevent this fracture, and it is usually an instantaneous force. An asphalt binder sandwich model is prepared by cutting the rocks into slices of regular thickness and then cutting them into prisms of regular shape and dimensions to suit the dimensions of the manufactured device. The asphalt bond that connects these prisms is of a known thickness. To calculate the strength of the thin asphalt binder confined between the rock prisms, a simple device was manufactured to calculate the amount of energy resulting from the collision of a specific block with the asphalt binder region, which reflects the amount of cohesion or bonding between the asphalt particles. The proposed device consists of an iron base to stabilize the asphalt binder sandwich model with a circular column to raise the hammer holder with a known and variable weight. The resistance of the asphalt binder, which depends on the cohesive forces of the particles of the material itself, increases with the increase in the thickness of the binder and also with an increase in the percentage of added additive up to 5% for both types styrene-butadiene-styrene (SBS) and crumb rubber.