“What’s the best flowable fill for pipe abandonment?” If the volumes are large, or the runs are long, it’s generally not the typical flowable fill you’d get from a ready mix company. The American Concrete Institute calls flowable fill “controlled low strength material,” or CLSM. There’s a specific type of CLSM that’s tailor made for high volume, long run abandonment grouting.
It’s LD-CLSM, or Low Density Controlled Low Strength Material. It’s far and away the best flowable fill for pipe abandonment, and most people call it cellular concrete. CJGeo generates thousands of cubic yards per week of it, and we call it CJFill.
Limitations of Traditional Flowable Fill
Most flowable fill mixes are primarily fine aggregate, with a modest amount of cement, and potentially a pozzolan such as fly ash to increase mobility. Most of these mixes are designed to be discharged into trenches, as opposed to being pumpable for hundreds, if not thousands of feet that are often required for pipe abandonment applications.
It takes a lot of energy to move significant quantities of fine aggregate. LD-CLSM replaces the fine aggregate in traditional flowable fill with small air bubbles. It’s really easy to move air, so by making flowable fill that’s 75% air, you instantly have material that’s pumpable more than a mile, depending on pipe size.
Where the Air Content Comes From
The air content in LD-CLSM comes from preformed foam. The preformed foam looks like barbasol shaving cream or cool whip. Specialty equipment mixes the cement paste and preformed foam. Sometimes the cement paste is delivered by ready mix companies. However, most of the time specialty batch plants that can make up to 200CY/hour of material generate the material onsite.
How Far Can You Pump It
The thing that makes CJFill-Ultra Lightweight the best flowable fill for pipe abandonment is the ability to pump the material over a mile. This does depend on pipe diameter–there are limits to how much material can be made in a day. For very small diameter pipes, like 6″ & 8″, it’s pretty common to pump up to 2500 linear feet per run. For very large diameter pipes, like 96″, the consumption per linear foot is so high that placements are typically multiple lifts.
Speak With An Expert
Facing a challenge? CJGeo abandons a few miles of pipe per week, from Maine to Miami to Texas. Give us a shout or shoot us a text. Click the state marker for the location of the project for contact info for the appropriate rep.
