GCP formulates agents neutralizing clay factor in sub-par aggregates

The former Grace Construction Products business arrived at 2017 ConExpo-Con/Agg with new sand & gravel additives and concrete admixtures aimed at mitigating poor quality aggregates’ effect on fresh mix and finished slab or structure performance. The Clarena product portfolio was front and center at GCP Applied Technologies’ Las Vegas Convention Center booth during the early-March show.

The ConExpo-Con/Agg booth display illustrated the potential for new GCP agents to bring marginal aggregates to concrete grade, based on measurements from ASTM C1777-15 Standard Test Method for Rapid Determination of the Methylene Blue Value for Fine Aggregate or Mineral Filler Using a Colorimeter.

“Clays can be particularly harmful to concrete mixes by absorbing large amounts of water and admixture, which leads to poor workability, reductions in strength, and increased plastic and drying shrinkage,” explains GCP Research Fellow Dr. Lawrence Kuo. With the diminishing availability of high-quality aggregates, he adds, the use of lower quality unconventional alternatives has been on the rise—resulting in concrete with increased process variability and higher production costs.

“We know it’s important for ready-mix and aggregate producers to provide consistent product performance,” says GCP Global Marketing Director Pung Chan. “The clay mitigating agents in the Clarena family not only remove production variability, but can also provide materials flexibility and cost savings … We are enabling [customers] to save on material costs, while improving concrete performance.”

Clarena additives, she notes, help quarry owners extend reserves; enhance yield and productivity; lower net waste compared to mechanical or equipment-based clay treatment solutions; and, can be formulated to address material deficiencies and variations arising from one region to another. “Aggregate producers can now convert waste into revenue and improve profitability,” Chan contends.

Clarena mid-range and high-range water reducing admixtures, on the other hand, ensure workability and finishability by creating a smooth flowing concrete within a wide target slump range, she adds.