How Flowable Fill Benefits Municipalities & Utility Departments
Flowable fill was initially developed as a solution to persistent problems stemming from poorly compacted soil or granular fill. These mixtures comprised of large amounts of fly ash and water and experienced large volume changes due to water evaporation. Extensive research and technology advancement pertinent to this mixture has led to its use in a variety of applications, including:
- Backfill for utility trenches;
- Paving subbase;
- Bridge abutment; and
- Retaining wall backfill.
Using flowable fill in other void-filling applications such as basements, tunnels, mines, sewers, and other underground structures have increased due to recent Environmental Protection Agency laws for below-grade fuel tanks.
What Is Flowable Fill?
It’s generally comprised of a cement, water, fine aggregate, and fly ash or slag combination. Many materials that don’t meet the quality standards for use in concrete have been used in these mixtures with favorable outcomes. Specifically designed chemical admixtures have become more common due to their positive effects on performance. Your local ready-mix producer may suggest mixtures that vary from these components depending on availability and the specified project requirements. The design flexibility of flowable fill mixtures offers many advantages to the engineer that must adhere to mix design specifications.
How Volumetric Mixers Use Flowable Fill
Volumetric mixers have performed this type of work for almost as long as the concept has been around. Most manufacturers offer a feature on the mixer or at least as an option to achieve the low strengths required for flowable fill projects.
One major project completed with flowable fill using volumetric mixers took place in California. AT&T had a small fleet of mixers equipped to produce a low strength fill to cover up fiber optic lines that would soon be used for high-speed internet. This low strength fill was perfect in this project because it was strong enough to protect the fiber optics, but not too strong to damage the lines.
A volumetric mixer is capable of producing low strength flowable fill, but with the flip of a switch, can adjust for use as a high strength concrete mixer. This allows many owners to be involved in the flowable fill business and to complete concrete work with the same machine. Since AT&T’s success, many municipalities and utility departments have seen the advantages volumetric mixers provide in this general area of construction.
Produce A Large Quantity Of Flowable Fill With A Mobile Concrete Mixer
Most flowable fill is used to backfill utility trenches, but many projects call for vast amounts of the mixture as well. The volumetric industry has manufactured equipment that not only achieves the mix design but also achieves the required production rates. The yield amount may vary for each type of mixer, but the required production rates can reach thousands of yards an hour depending on the project. This is typically where you’ll see a 10-yard volumetric mixer that produces more than 100 yards an hour.
If you have any questions about extra opportunities that flowable fill or volumetric mixers can provide, do not hesitate to call Cemen Tech at (800) 247-2464 or contact us.