Moisture-induced strength degradation of aggregate-asphalt mastic bonds

Apeagyei, Alex K.; Grenfell, James; Airey, Gordon

Abstract

A common manifestation of moisture-induced damage in asphalt mixtures is the loss of adhesion at the aggregate–asphalt mastic interface and/or cohesion within the bulk mastic. This paper investigates the effects of moisture on the aggregate–mastic interfacial adhesive strength as well as the bulk mastic cohesive strength. Physical adsorption concepts were used to characterise the thermodynamic work of adhesion and debonding of the aggregate–mastic bonds using dynamic vapour sorption and contact angle measurements. Moisture diffusion in the aggregate substrates and in the bulk mastics was determined using gravimetric techniques. Mineral composition of the aggregates was characterised by a technique based on the combination of a scanning electron microscope and multiple energy dispersive X-ray detectors. Aggregate–mastic bond strength was determined using moisture-conditioned butt-jointed tensile test specimens, while mastic cohesive strength was determined using dog bone-shaped tensile specimens. Aggregate–mastic bonds comprising granite mastics performed worse in terms of moisture resistance than limestone mastic bonds. The effect of moisture on the aggregate–mastic interfacial bond appears to be more detrimental than the effect of moisture on the bulk mastic.

Citation

Apeagyei, A. K., Grenfell, J., & Airey, G. (in press). Moisture-induced strength degradation of aggregate-asphalt mastic bonds. Road Materials and Pavement Design, 15(S1), https://doi.org/10.1080/14680629.2014.927951

• Journal Article Type: Article
• Acceptance Date: Nov 2, 2013
• Online Publication Date: Jun 19, 2014
• Deposit Date: Apr 4, 2018
• Publicly Available Date: Apr 4, 2018
• Journal: Road Materials and Pavement Design
• Print ISSN: 1468-0629
• Electronic ISSN: 1468-0629
• Publisher: Taylor & Francis Open
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: S1
• DOI: https://doi.org/10.1080/14680629.2014.927951
• Keywords: asphalt mastic, adhesive strength, bitumen, diffusion, moisture-induced damage
• Public URL: https://nottingham-repository.worktribe.com/output/730373
• Publisher URL: https://www.tandfonline.com/doi/abs/10.1080/14680629.2014.927951
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Road Materials and Pavement Design on 19 June 2014, available online: http://www.tandfonline.com/10.1080/14680629.2014.927951.