Induction healing

Induction-healing is the first method capable of healing micro-cracks in pavements, thereby preventing asphalt raveling and similar more advanced degradation mechanisms from occurring.

Steel fibers are incorporated in the asphalt mixture, rendering it electrically conductive. When micro-cracks in the pavement are on the verge of evolving into raveling, these fibers are heated by an alternating magnetic field, generated by an induction coil. The produced heat melts the bituminous binder, allowing bitumen to flow into the cracks. This restores the bond between asphalt constituents, closing of the cracks and halting accelerated degradation processes that would otherwise give rise to raveling (and related phenomena). The heating treatment can be repeated at later dates, when degradation processes again threaten to compromise the pavement’s structural integrity.

Rejuvenation capsules

Epion’s rejuvenation capsules are embedded in the binder of a new pavement to revert the effects of aging on bitumen. As micro-cracks develop in the bituminous binder the capsules are opened, and a liquid rejuvenator is released which flows into the cracks. Diffusion of the rejuvenator in the bitumen remits its stiffening, restoring the binder to its original state. Although rejuvenation capsules can be implemented separately, induction-heating allows for more effective diffusion of the rejuvenating fluid. Hence, embedding rejuvenation capsules in healing pavements significantly boosts their performance.

Induction Aid

Induction-Aid or ‘I-Aid’ is a perfect example of epion’s ability to unearth the untapped potential of self-healing technology and illustrates the value of our expertise. Whereas induction healing prevents potholes and other dangerous defects from occurring, I-Aid can be employed to repair the pavement after they have. I-Aid uses prefabricated asphalt patches, encased in a bonding-layer containing conductive steel particles. Segments of the pavement surrounding the potholes are cut out with a hole saw and replaced with these asphalt patches. Once in place, a bond between the repair patch and the old road is established by applying induction heating and light compaction. Although epion will also offer standardized patches, both their dimensions and the asphalt mixture they contain can be modified if needed.

Our induction-based repair method has many advantages over conventional alternatives, primarily because it relies on in-factory prefabrication. Since replacement patches are made beforehand, on-site maintenance activities are safer, take up far less time and produce comparatively little debris. In addition, epion can guarantee delivering high-quality products, as it can oversee the manufacturing-process.

Expressways

Induction healing technology can be applied fruitfully in any type of asphalt pavement. Since it significantly extends service-life however, its application is particularly advantageous in porous asphalt pavements. With an average service life of 8-10 years, (conventional) porous asphalt roads have much shorter life cycles than dense graded pavements (18 years). Despite of this drawback porous asphalt is often used in the construction of important expressways, as it outperforms its counterpart in several respects. Due to its open graded nature, porous asphalt reduces traffic noise and facilitates water drainage. The latter greatly improves road safety because it prevents splash-and-spray and aquaplaning.

In the Netherlands, 80% of expressways are surfaced with porous asphalt on account of its superior performance. In an effort to remediate porous asphalt’s one major flaw, its relatively short service-life, the Dutch Ministry of Infrastructure and Environment commissioned the implementation of induction healing technology at several locations in the Netherlands. An early experiment in the A58 express-way near Vlissingen is particularly worthy of note. Here a 400 meter long strip of self-healing pavement has been open to traffic since 2010. This strip has already been healed successfully via induction-heating. According to the Dutch Ministry of Infrastructure, implementing induction healing in all expressways in the Netherlands could save 90 million euro's in maintenance costs per annum.

By extending its service-life, healing technology removes the most important barrier to the implementation of porous asphalt. Epion’s products thereby remove the need to choose between durability and performance: with self-healing porous asphalt, you can have both.

City streets

Maintenance of city streets comes with its own special set of difficulties, presenting a challenge epion gladly takes on. Situated in busy urban areas, performing repair activities on these roads is exceptionally disruptive to traffic and/or complicated by lack of space. These maintenance difficulties make the implementation of self-healing technology in new pavements an attractive option in metropolitan areas. Compared to conventional alternatives, healing pavements require less invasive maintenance, less frequently.

With our revolutionary induction-based repair method I-Aid, epion offers a far less invasive, less time-consuming alternative to conventional on-site repair procedures. Pavement defects in city streets are prevalent in zones surrounding traffic lights, roundabouts, intersections and the like. These areas are subject to more forces, as a result of the frequent acceleration and deceleration of vehicles in these zones. Hence certain segments of the road might urgently require repair, while the rest of the pavement is still in good condition. With I-Aid, epion offers a cost-effective method to replace defective segments of the road with pavement of unmatched quality.

Aviation industry

Airports demand more from their pavements than any other organization. Rightly so, for when runways have to be closed for maintenance, airports do not just lose revenue as a result of having to turn down business. A burden is also placed on other runways, those that have to compensate for the loss of capacity, and airports may even suffer legal penalties as a result of failing to meet flight demand. Given these large costs, airports have an added incentive to minimize downtime and extent pavement service life by implementing epion’s products. Induction healing technology has two additional benefits that deserve mention here, as they make application in runways particularly worthwhile:

1. Airports in cold climates use a variety of methods to clear runways from snow and ice. In addition to mechanical methods and de-icing fluids, runways can be equipped with integrated heating systems. De-icing fluids are either harmful to the environment or to aircraft, damaging carbon brakes and corroding cadmium-plated plane components. Integrated heating systems, however, are incredibly expensive as they involve embedding either an array of pipes to hold a heating fluid or electric wires into the pavement. Both systems distribute heat inhomogenously, thereby imposing restrained thermal deformations that cause damage to the pavement. Aceso, epion’s induction-heating vehicle, heals two proverbial wounds with one kiss when applied to runways. The steel fibers that induction healing requires to be incorporated into the pavement can also serve as a superior alternative to the integrated heating systems used at present. Because these steel fibers are distributed evenly over the pavement’s surface, imposed retrained thermal deformations are less likely to occur. Since induction technology also extends pavement service life, it is a much more attractive investment than any stand-alone heating system. The appeal of this double-functionality will result in decreased use of harmful de-icing fluids, since a more sustainable alternative is available for runways equipped with self-healing technology.

2. The surface of runway pavements has to be much more resilient, due to the higher impact load of aircraft. This is a lasting concern, since modern-day airports have to accommodate increasingly heavier aircraft and a growing number of flights. The steel fibers necessary for induction healing can help airports meet these demands, as they also enhance the pavement’s structural integrity, allowing it to withstand heavier loads.

These added advantages, combined with healing technology’s ability to minimize downtime and extent pavement service life, make the implementation of epion’s products an absolute no-brainer for the aviation industry.