Effect of steel wool fibers on mechanical and induction heating response of conductive asphalt concrete

ABSTRACT

This study characterises the mechanical, rheological, induced heating, and induced healing behaviour of asphalt concrete containing steel wool fibers (SWFs) as the conductive constituent. Induced heating of asphalt concrete through the electromagnetic field is a novel method to heal the damage induced in asphalt concrete. Previous studies used high contents of the SWF as the conductive material to improve the sensitivity of the asphalt concrete to the electromagnetic radiations. Experimental tests conducted in this study (e.g. uniaxial strength, indirect tension, semi-circular bending tests) show that the addition of 0.2 (wt)% SWF meets both the heating and healing requirements. The relatively low amount of SWF resulted in considerably less adverse effects on the mechanical and rheological properties of asphalt concrete comparing to higher percentages of SWF (e.g. 1.5 (wt)% of SWF). Tests conducted on different specimen sizes of asphalt concrete reveal substantial effects of specimen dimension (volume) on the heating rate that should be considered in the evaluation of asphalt concrete induction heating under electromagnetic power. In addition, it is shown that using 0.2 (wt)% SWF significantly reduces the effect of corrosion on induced heating of conductive asphalt concrete materials. Experimental results demonstrate that the tensile strength ratio (TSR) decreases from 25% for 1.5% SWF to 7% for 0.2% SWF.

KEYWORDS:

• Conductive asphalt concrete
• induction heating
• induced micro-damage healing
• steel wool fiber (SWF)
• microwave heating

Acknowledgment

The experiments described and the resulting data presented herein, unless otherwise noted, were funded under PE 0603734, Project T15 ‘Military Engineering Technology Demonstrations,’ Task 10 under Contract W912HZ17P0116, managed by the US Army Engineer Research and Development Center. Permission was granted by the Director, Geotechnical and Structures Laboratory, to publish this information.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The experiments described and the resulting data presented herein, unless otherwise noted, were funded under PE 0603734, Project T15 ‘Military Engineering Technology Demonstrations,’ Task 10 under Contract W912HZ17P0116, managed by the US Army Engineer Research and Development Center.