Today we thought we’d touch on the subject of moisture correction in concrete mix design. It’s a subject that has centuries of research and development behind it. This R&D leads us past some of the oldest structures on earth all the way up to modern facilities producing precast concrete forms, such as Rogue Valley Precast.
One of the great things about concrete’s continuing popularity is that concrete itself is subject to near-continuous quality control procedures and improvements. Not only is concrete the world’s most popular building material, but it’s also one of the world’s most studied and examined.
Consider that concrete has been used in construction projects throughout the world for literally millennia. Many of the world’s most ancient structures are made of concrete. Many of them remain standing to this very day, and a good number of them are still functional.
What we’re getting at here is that concrete and its modern precast concrete counterparts undergo rigorous analysis and review every single day. And it’s been that way for hundreds if not thousands of years.
That’s why so many concrete processes are so well-defined, including the process of moisture correction in concrete mix design.
Concrete Mix Design: Moisture Correction
The higher the water-to-cement ratio, the lower the concrete’s compressive strength. A higher ratio also makes for a less durable and less watertight concrete product. In order to maximize concrete’s renowned compressive strength, we must minimize the water-to-cement ratio.
That’s why we perform moisture correction in our concrete mixes. We can determine the ratio via simple mathematical formulas that take into account such things as the water weight of the concrete mix and the weight of the rest of the cement materials (e.g., Portland cement, fly ash, if applicable, etc.).
Proper and adequate ratios depend on a number of factors. The customer or contractor may specify a ratio. More likely it’s the municipal or regulatory authorities who make that determination for a specific type of project. In fact, it is part of a contractor’s responsibility on a project to clarify concrete properties for the producer.
One final important note about moisture correction in concrete: Precast concrete producers must make these adjustments in batch water for aggregate moisture content. Dry aggregates require extra batch water. Wet aggregates require less batch water. The proper adjustment depends on multiple variables, including how porous the aggregates are.
Questions? Get in touch with Rogue Valley Precast!