From warehouses to retail and grocery stores, polyurea is outperforming traditional epoxy, silicone and polyurethane materials to fill and seal concrete slab control joints.

Control joints, also called contraction joints by the American Concrete Institute, are planned gaps that allow a crack to occur at a weakened area to help prevent random cracking. Concrete joints and their filler material endure many stresses during the slab curing period and service life, including shrinkage, traffic loads and thermal cycling.  In these slabs, the saw-cut control joint edges require protection to avoid serious spalling and deterioration where traditional materials are not always up to the task.

Efficiency and Productivity
According to a California-based sealant, caulking, waterproofing and membrane system contractor, silicones and polyurethanes make good control joint sealants, but they take at least 24 to 48 hours to fully cure and do not have the shore hardness to be reliable joint fillers. On the other hand, epoxies have the shore hardness to be joint fillers and can cure in four to eight hours, but are not flexible or adhesive. They can crack on both sides of the concrete and disbond prematurely.

As such, a growing number of contractors have turned to polyurea as a superior control joint filler and sealant for new construction, remodels or remediation.

Because polyurea cure quickly, joints can be filled during a lunch hour, and the concrete slab can be returned to service that afternoon. This helps with accelerated building timelines, when racking, fork lifts and trucks come in right after the floor is done.

Some polyuria systems start to set in about 90 seconds and are tack free in about 10 minutes—optimizing end user timelines as well as contractor productivity. In contrast, applying epoxy usually takes two applications, requiring a work crew to return the next day after curing.

Warehouses, Freezers and Showrooms
Contractors and end users are turning to performance-formulated polyurea for a wide range of specialized applications—from indoor concrete slabs in controlled environments to public access sidewalks fully exposed to outdoor thermal cycling and heavy foot traffic.

According to a Wisconsin-based joint filling, caulking, and spray foam contractor,  forklift wheels and forks often hit the concrete slab control joints in high-traffic warehouses and loading docks, causing big spalls.  Polyurea provides additional protection from heavy, hard wheel dollies and forklift traffic, which can cause joint edges to shoulder and spall.

In freezers and cold storage environments, polyuria can cure from -40 degrees to 130 degrees, can be returned to service in an hour, and is approved by the U.S. Department of Agriculture and Food and Safety Inspection Service.

Performance-formulated polyurea also have been used in grocery stores, retail showrooms, big box stores, and other venues, including polished concrete and decorative concrete applications. They come in 68 standard colors and hundreds of custom colors so the control joint can be accented with colors or patterns that complement the floor stain. 

In warehouses with specific staging areas for truck loading, some polyurea colors can be inset as line striping for safety or product staging.

 
Del Williams is a technical writer based in Torrance, Calif., who writes about business, technology, health and educational issues. For more information on polyurea, call 800-321-0906 or visit versaflex.com.