Have you ever seen an 11,000-square-foot concrete floor without joints or cracks? You can in Murray City School District (MCSD), one of the first Utah school districts to use traditional polished concrete floors in school common areas. Their first concrete floor attempts had joints that resulted in cracks, slab curling, inconsistent grinding, and continuous maintenance to clean and caulk the joints. In some areas shrinkage opened cracks large enough that slabs had to be replaced. During the design phase for the new Hillcrest Jr. High School, MCSD challenged Hughes General Contractors to create a concrete floor to rectify these issues as an alternative t o conventional vinyl flooring.

Fortunately, the contractor had a year before the floors needed to be placed. Hughes conducted extensive research about solutions to prevent or control cracking. Because concrete has high compressive strength but is weak in tension and shrinks as it cures, they made various attempts to regulate and control its inherent cracking.

Conventional wisdom pairs rebar with concrete to overcome the concrete’s weakness in tension. However, in the contractor's experiments it created unanticipated flaws. They discovered that rebar prevents natural concrete shrinkage from occurring. In a structural floor, this is of little consequence, but when penetrating stain and polish were applied, previously invisible hairline cracks were accentuated every few inches. The contractor had solved one problem but created another. The product designed to prevent concrete from cracking was causing tiny but unsightly cracks in the concrete.

Over the course of several months Hughes General Contractors poured around 100,000 square feet of test slabs. Each time they found small things to change to improve the outcome. Ultimately. they developed a process that allowed them to eliminate more than 95% of the saw-cut joints and most of the cold joints.

Hillcrest Jr. High School’s 11,000 square feet of common and cafeteria area was achieved with a single pour. Hughes' patent-pending process produced a flawless slab that is about 125 feet by 90 feet without a single saw cut, joint, or crack. The exposed concrete has been polished and colored to display blue, charcoal, and natural gray rectangular patterns, giving it the appearance and durability similar to terrazzo at a cost comparable to carpet or LVT. In lieu of using saw cuts to delineate the transition between the three colors of stain, they developed a process of tensioned masking that resulted in perfectly straight ¼-inch lines where the saw cuts would have been.

The floor's maintenance cost is, and will continue to be, a very small fraction of the cost of maintaining traditional floor coverings. Hillcrest’s concrete contributed to creating a building that is functional, aesthetically pleasing, and within budget.

As an added benefit, this floor is very sustainable and environmentally friendly, and because floors typically fail starting at the joints, the life expectancy of this floor should be indefinite. This technology creates a stunning visual impact through the continuous, smooth appearance of unbroken concrete.