Microwave self-healing technology as airfield porous asphalt friction course repair and maintenance system

A problem increasingly faced by airport authorities is the maintenance of runways. Due to their large aircraft loadings associated with take-off and landing operations, runways experience surface deterioration. Poor quality runway surfaces cannot be tolerated in such an environment. Maintenance issues must be carried out to maximise safety and minimise the risk of aircraft damage. A recent development has been the introduction of self-healing technologies such as rejuvenator encapsulation, induction and microwave heating to address these issues. This paper summarises a laboratory investigation to determine the effectiveness of microwave self-healing for crack repair of Porous Friction Course (PFC) used for airfields. Four mixtures containing varying percentages of conductive steel fibre were tested. Their relative performance was assessed using the Indirect Tensile Stiffness Modulus (ITSM) and Indirect Tensile Strength (ITS) test methods. The results show that the addition of conductive steel fibre increases initial stiffness and strength of the mix. A combination of micro-wave heating and steel fibre addition to the mix indicates that it is possible to significantly improve asphalt performance by making it self-healing to structural problems such as cracking.