Evaluation of self-healing of asphalt concrete through induction heating and metallic fibers. (15th August 2017)

• Record Type: Journal Article
• Authors: Pamulapati, Yashwanth; Elseifi, Mostafa A.; Cooper, Samuel B.; Mohammad, Louay N.; Elbagalati, Omar
• Is Part Of: Construction & building materials. Volume 146(2017)
• Page Start: 66
• Page End: 75
• Publication Date: 2017-08-15
• Subjects: Induction heating -- Self-healing asphalt concrete -- Fracture resistance -- Steel fibers; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2017.04.064
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Aluminum fibers were used to achieve healing through induction heating. Specimens with steel coupled better to induction than specimens with aluminum. Cracks with width of 0.639 mm completely healed after the recovery period. Loading capacity of the specimens was measured before and after the recovery period. Abstract: While healing through induction heating is promising, the effectiveness of this technology is yet to be demonstrated as limited studies have been conducted to study the recovery of cracking damage and fracture resistance properties after healing. The objective of this study was to test the hypothesis that a new generation of asphaltic materials could be artificially healed while in-service by embedding metallic fibers in the mix and by applying a magnetic field at the surface. To achieve this objective, an open-graded friction course (OGFC) was successfully designed and prepared to incorporate up to 5% steel and aluminum fibers by weight of the mix. Based on the results of the study, it was found that the control mix and the mix prepared with aluminum fibers exhibited greater ultimate load at failure prior to healing than the specimens with steel fibers. Yet, differences were not statistically significant. The induction heating experiment was conducted successfully and showed the feasibility of inducing Eddy currents in the metallic fibers without contact to the specimens. After healing, the control mix had the highest ultimate load after healing although it was not successfully heated through Eddy currents; yet, differences were not statistically significant. This indicates that other healing mechanisms were present that allowed the control specimens to heal during the recovery period. Healing efficiency was the highest for the control specimen as it approached 85%. Healing efficiency for the specimen with aluminum and steel fibers was 72 and 62%, respectively. Microscopic image analysis demonstrated that induced cracks healed efficiently during the recovery period.