Fill Flow

  • Overview
  • Packaging
  • FAQs
  • Advantages
  • Resources

Sometimes the traditional way of doing things may not always be the most effective.  Perhaps nowhere in the concrete industry is this more true than in the production of controlled low-strength material, also known as flowable fill. Traditionally, these mixes have been made with excessive amounts of water.  While this does increase the flow of the concrete, it also increases bleed water.  Fortunately, Fritz-Pak’s innovative Fill Flow is a unique flowable fill concrete admixture that uses entrained air to improve the flow of the concrete.

How Does This Flowable Fill Concrete Admixture Work?

Fill Flow is specially formulated with powerful air entraining chemicals to dramatically increase the air content of the mix. The billions of air bubbles allow the mix to flow easily and make it easier to place within trenches.  Because of the increased flowability, the flowable fill concrete admixture gives you the option to discharge the mix directly from the truck into the trench, rather than using a pump.  This will save you both time and money at the job site.  And if you have to pump the mix, Fill Flow makes an easy-to-pump mix that doesn’t segregate.

Want More Information?

If you need more information about designing a mix with our flowable fill concrete admixture, give us a call at (214) 221-9494.  If you would like to try out Fill Flow, you can request a free, no-obligation sample.  And when you’re ready to place an order, you can easily do that through our online store. Don’t forget to follow our social media pages for all the latest on Fritz-Pak’s powerful concrete admixtures.

956691 lb. water soluble bag2430
9567050 lb. paper bag40
What kind of admixture is Fill Flow?
It is a very high strength surfactant that causes air bubbles to form in high mineral concentration solutions, such as cement pastes.
How does Fill Flow work?
It creates billions of air bubbles that serve as "ball bearings" within the flowable-fill and increase the flow properties.
What kind of unit weight can I expect wih Fill Flow?
Unit weight is dependent on mix design and size of sands. Typically you should expect a unit weight of 90-120 lbs./cu.ft.
What is the recommended addition procedure for Fill Flow?
It should be added at the jobsite. Fill Flow will increase the volume and flowing properties of the flowable fill. If added at the plant, the possibility of spills during transport are increased.
Compared with flowable fill without any admixtures, do I need more or less water to produce flowable fill with Fill Flow?
You will need less water. Typically you will only use 25-30 gallons of water per cubic yard of flowable fill.
Since I am increasing the air content of the flowable fill with Fill-Flow, will I also experience a reduction in strength of the flowable fill?
No. You are increasing the air content, but you are also reducing the water content. As you reduce the water-cement ratio, the cement paste increases enough strength to compensate for the increased air content.
Can Fill Flow be used in mixes containing other cementitious materials, besides cement, such as fly ash or granulated blast furnace slag?
What standards does Fill Flow meet?
Currently there are no national standards for additives for flowable fill. Most states have specifications for the flowable fill produced, not necessarily for the type of admixture used to produce it.
Can Fritz-Pak help me develop a flowable fill mix design?
Are there any additional benefits to using Fill Flow?
Yes, flowable fill produced with Fill Flow is more pumpable, it discharges from the ready mix truck faster and also the truck is easier to clean.
For pumping flowable fill long distances, what do you recommend?
Besides making the flowable fill with Fill-Flow we recommend adding one bag of Slick-Pak II for every 3 yards to improve pumpability.
  • Patented water-soluble Fritz-Pak bag readily breaks down even in very fluid mixes.
  • Easy handling and storage because Fill Flow is a dry powder, not a liquid.
  • No problems with leakage, heat damage, or freezing.
  • Produces an extremely fluid material with minimal shrinkage or segregation.
  • Controlled Low Strength Material (CLSM) can be placed directly from the ready mix truck.
  • Eliminates the need for compaction of layered backfill.
  • Produces very stable air content.
  • Significantly faster and less labor intensive than compacted soil fill.


Fill Flow is compatible with all conventional CLSM materials. Fill Flow contains no calcium chloride or other corrosive agents. Superplasticizers, water reducers and dispersants may reduce the effectiveness of Fill Flow.