Breixo Gómez-Meijide

The Effect of Hydrated Lime on the Bond Between Asphalt and Recycled Concrete Aggregates

In this investigation, rolling bottle tests and boiling water tests were performed to evaluate the effect of hydrated lime on the adhesion between recycled concrete aggregates (RCA) and the asphalt binder. RCA from construction and demolition waste (C&DW) were used in this investigation. To generalize the findings, three asphalt penetration grades were analyzed: B40/50, B60/70, and B150/200. The results indicate that the use of hydrated lime does not improve the RCA-aggregate bond. Additionally, the results indicate that a higher asphalt-aggregate adhesion correlates to a lower asphalt penetration grade.

Self-Healing of Dense Asphalt Concrete by Two Different Approaches: Electromagnetic Induction and Infrared Radiation

Cracks in asphalt mixture can self-heal if enough resting time (hours or days) is given. This is a viscosity dependent phenomenon that can be accelerated by increasing the temperature of asphalt mixture. In the present paper, the healing performance of asphalt mixture heated using infrared heating to simulate the natural solar radiation, and induction heating, a new method to increase the temperature of asphalt pavements, were compared in terms of time and healing temperature. Healing was defined as the relationship between the 3-point bending strength of an asphalt beam before and after healing. The results show that both methods reach similar and satisfactory healing rates at around 90 %. However, induction heating is more energy-efficient, since the effect is concentrated on the binder, instead of heating the whole mix. This means much shorter healing times to reach the same healing rate than with infrared radiation. Finally, it was found an optimal radiation energy, from which on, infrared radiation reduces the material healing properties.