Cutting-Edge Densifiers

The depth and clarity of ground and polished concrete is enhanced when lithium silicate is included. Photo courtesy of L.M. Scofield Co.

The customer walking the concrete floor at the big-box retail store thinks a concrete floor is hard. So does the worker driving the forklift across the concrete floor of the warehouse. But concrete contractors know that concrete is soft: subject to abrasion, wear, efflorescence, dusting and dulling. That is why contractors and experts who know concrete recommend using a densifier for any floor that will be subject to heavy traffic, wear or abrasion.

Densifiers are typically solutions of silicates that react with any calcium hydroxide that was not bound during the hydration of a concrete slab. Sometimes called liquid hardeners, they impregnate the surface of a cured concrete slab with silica, the basic element of quartz. They essentially complete the hydration process by turning this material into calcium silicate hydrate (CSH), strengthening the concrete matrix.

A densifier offers several advantages, according to Clif Rawlings, product manager and training coordinator for HTC Professional Floor Systems. First, it delivers a denser, harder surface for polishing, heightening the resulting shine, particularly in softer concrete. Second, it blocks efflorescence caused by moisture coming from below the slab. Densified concrete is breathable, but the altered pore structure stops the passage of minerals that cause efflorescence on the surface. Third, it increases abrasion resistance, which increases the longevity of the shine. "We did an informal test in our own warehouse, grinding and polishing one area without densifying it," Rawlings says. "You can see that the densified area holds up better to forklift traffic."

Densifiers...

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