Rapid Drying Concrete helps prevent moisture-related flooring problems and contribute to a healthier environment.

Concrete Green Building Blog (Feb 1 2012) Concrete

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   Every year, moisture-related flooring problems (and the disputes that follow) add hundreds of millions of dollars to project costs. Scores of topical approaches have been introduced to try to mitigate the effects of high moisture levels in concrete slabs. These treatments, however, can add significant costs to a project, be disruptive to apply, and, to date, have not proven to be 100% effective.
   
   THE PROBLEM
   
   The effects of a high moisture condition in concrete can be damaging to modern-day flooring installations. Adhesive breakdown, debonding, and blistering are all conditions related to moisture and moisture-induced high pH levels that develop when moisture in concrete is high. Adhesive, flooring, and coating manufacturers have responded by specifying maximum concrete moisture levels needed prior to the installation of their products. Unfortunately, it’s rare for conventional concrete to dry naturally to these levels within desired project schedules. Also, the state of concrete dryness is often not known until shortly before flooring materials are to be installed. If tests show that the concrete is too wet for flooring installation, meeting the project schedule may force the installation of an expensive topical solution—an installation that’s especially challenging and disruptive because the interior walls may already be in place. A better approach is needed.  
   
   THE CONCRETE SOLUTION
   
   Over the years, a number of approaches have been tried to accelerate the drying time of concrete. These have included the development of quick-drying mixtures with low water-cement ratios (w/c).1,2 While these first-generation mixtures can be effective in hastening concrete’s drying time, they have proven to be too difficult to place and finish on a regular basis. Today, things are about to change. After more than 6 years of development, laboratory testing, and field verification, a new concrete solution has been developed that combines the benefit of rapid drying with placement and finishing characteristics similar to those for conventional concrete. Called Aridus™ (Latin for “dry”), this new portland cement-based concrete solution combines years of practical experience, modern proportioning technology, and a unique chemistry. The new concrete not only dries quickly, but it’s also not seriously affected by re-wetting. Yet, this unique concrete mixture can be placed using conventional equipment, including concrete pumps, and it can be finished using standard equipment, including laser screeds, conventional vibratory screeds, pan floats, and power trowels.

    

   THE ADVANTAGES
   
   The significant advantage to this cost-effective concrete solution is its ability to stop slab moisture problems from the very beginning. No longer will project schedules need to be disrupted by extended drying times or the time required to apply a topical moisture and pH suppression system. Eliminating slab moisture issues from the beginning will spare owners and the project team the aggravation and cost of dealing with post-installation corrections to failed flooring. Disputes over responsibility and cost will be avoided, so everyone will be able to complete their tasks and responsibilities without interruption.Results of field and laboratory moisture testing of this new concrete solution indicate that, on most projects, the concrete will be ready to accept flooring in less than  30 days following watertight enclosure of the building.

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