Effect of hydrated lime on fracture performance of asphalt mixture

• A modified conditioning procedure was used to better simulate field conditions.
• The hydrated lime helped stiffen the mixture without increasing its brittleness.
• The hydrated lime helped reduce rate of damage accumulation in the mixture.
• Introduction of hydrated lime resulted in better fracture performance.
• The lime-treated mixture was found more cost-effective than the untreated one.

A recently developed conditioning procedure was employed to better simulate effects of field conditions on asphalt mixtures. The energy ratio (ER) approach, capable of integrating various factors affecting cracking performance, including key mixture properties and pavement structure, was used to evaluate the effect of hydrated lime (HL) on fracture performance of conditioned and unconditioned asphalt mixtures. The results showed that HL was beneficial in resisting detrimental effects on damage and fracture-related properties caused by the conditioning. Also, HL resulted in better fracture performance for the same design asphalt concrete layer thickness, or in less cost to achieve the same performance.