Hardwire is made from ultra-high-strength twisted steel wire chords in a thin "open" mesh configuration.

For more than 40 years, various forms of polymer based flooring systems have been successfully applied to concrete surfaces. These systems have become mainstream forms of protection against aggressive chemicals, abrasion and impact while also offering an appealing aesthetic appearance. However, there is a movement to further enhance polymer based flooring systems as the need for improved structural capacity increases on our industrial floors. In reality, material handling equipment is getting heavier, buildings are experiencing loads for which they were not originally designed - including loads from potential explosions - and floors are being taxed beyond their capacity.

According to Jay Thomas, vice president for Structural Preservation Systems, polymer flooring systems offer little or no benefits in terms of increasing structural capacity or resisting cracking when excessively flexed. Further, says Thomas, polymer systems have been problematic in flooring applications when used on cracked concrete slabs as these cracks may allow reflective cracking through the polymer topping, hence compromising the system.

After priming the floor surface, Hardwire can be applied in a continuous manner or cut into specific lengths.

For example, Structural Preservation Systems recently retrofitted a heavily reinforced concrete slab for a leading national home improvement warehouse. Since the slab was constructed on soils that were not capable of supporting the required loads, it was cast on top of a piling system, basically creating an elevated slab. When constructed, the steel reinforcement was inadvertently placed too low in the slab, creating structural capacity issues, cracks, difficult trafficking, and challenging cleaning and aesthetic problems. Removing the slab was both costly and disruptive to store operations.

The solution involved application of Hardwire® - the same technology used in steel-belted radial automobile tires. Developed by Hardwire, LLC, the proprietary technology is a family of reinforcements made from ultra-high-strength twisted steel wire chords. The product can be molded into or on virtually any structure or part and provides high strength (up to 8,000-lbs./in. and high modulus (up to 30MM psi) in a very thin, ductile envelope. Although Hardwire does not replace today's polymer flooring systems, the addition of Hardwire dramatically strengthens today's retrofit flooring design capabilities.

Skip Ebaugh, vice president of Hardwire, LLC, said the combination of polymer flooring with these thin steel belts creates a system with the ability to increase structural capacity, blast resistance and general "toughness" of the concrete. Applications include heavily trafficked warehouses, manufacturing slabs, elevated slabs, slabs on pile construction, and slabs that are structurally deficient from improper design or construction. Further, said Ebaugh, because of the global economies of scale afforded from mass production of steel belted tires, Hardwire is produced at a small fraction of the cost of typical composite reinforcements.

How it works

A filled polymer base coat is applied over the Hardwire, followed by a clear, chemical and abrasion-resistant coating.

The first step in application is actually performing any necessary concrete repair and surface preparation. After priming the surface, Hardwire is then applied in two plies, usually at a 0/90 deg. orientation. Since it is available in a continuous form, Hardwire can be applied in a continuous manner or cut into specific lengths. Once installed, the Hardwire reinforcement offers a thin (50-100 mils) open "mesh" configuration that can be easily encapsulated with a polymer flooring system. A filled polymer base coat is applied onto the Hardwire. Then, a clear coating that is chemical- and abrasion-resistant is applied, completing the flooring system at approximately 200 mils in thickness. If desired, decorative finishes can be applied. And, with no volatile organic compounds (VOCs) present in the system, it is a viable solution where emissions and odors are an issue.

Structural Preservation Systems also used Hardwire recently to repair a heavily trafficked elevated slab in a multi-story warehouse/distribution facility for a large automotive parts distributor in Illinois. The long-term dynamic loading of fork trucks, as well as the increase in size of such trucks since initial design of the facility, had resulted in a myriad of distress scenarios in the concrete. The flexing in the concrete floor had resulted in numerous cracks and repairs would last for a mere few weeks at best. A flooring solution was needed that not only would serve as a thin resurfacing system but would also add considerable structural capacity to the more than 10,000-sq. ft. of truck aisles.

The finished floor offers the "toughness" of concrete with increased structural capacity and blast resistance.

According to Thomas, the solution involved the application of Hardwire with a polymer flooring system cast on top of it. To minimize downtime for the owner, the project was broken down into multiple phases and all work was completed on a weekend schedule. After an initial inspection, some badly deteriorated sections of the concrete floor were completely removed and recast with high-strength, rapid-setting concrete. Tenting and ventilation were set-up to contain any possible dust and debris during preparation and removal of old, failed floor toppings. Hardwire material providing 1,400-lbs./in. in both directions was then applied in a 0/90 deg. lay-up (the equivalent of approximately #3 rebars at 6-in. on center in both directions). A gray polymer base coat was applied and allowed to cure. Then a high wear clear topcoat was applied and rapidly cured using an innovative polymer technology that almost instantaneously cures when a high-intensity UV light unit is rolled over it. This topcoat allows immediate foot traffic and heavy wheel traffic within a few hours compared to the 24-hr. cure time of most topcoat systems. The completed system was ready for traffic with little disruption to plant operations and the process was repeated the following weekend.

Sensible Solution for Sensitive Areas

Hardwire reinforcement is a system that offers solutions to upgrade problems that could previously not be addressed, says Thomas. Its ability to be integrated with multiple polymer and cementious materials allows for affordable and timely solutions to challenging infrastructure repairs such as structural and blast upgrades - while using time-tested materials such as polymers, mortars and tire cords.