Cellular Grouting
Been There. Grouted That.™
Cellular grouting uses low density cementitious grout as an alternative to traditional weight grouts. Cellular concrete is a type of controlled low strength material (CLSM). CLSM generally refers to flowable fill or mix designs specifically formulated for relatively low, but predictable, strengths. The “cellular” in cellular grout refers to the preformed cellular concrete foam used to generate the material. Instead of sand and stone aggregate, cellular Low Density Controlled Low Strength Material has uniformly-distributed air bubbles. Sometimes sand is used, but it’s at much lower quantities per cubic yard than traditional CLSM. This lowers unit weight significantly. Foaming is done either through truck batching or continuous generation.
Types of Cellular Grout
closed cell
Traditional cellular grout is closed cell. Effectively, the preformed foam bubbles have a stronger desire to be surrounded entirely by cement paste than in contact with adjacent bubbles. This isolates each bubble, minimizing the ability of water to pass from bubble to bubble. CJGeo primarily utilizes Aerlite-iX, a synthetic preformed foam for generating closed cell cellular grout.
Permeability is still correlated with density; very low density closed cell material has permeabilities similar to coarse sand. As density increases, permeability decreases.
open cell
With Type I/II cement, utilizing open cell preformed foam, such as Aquaer-iX, can provide permeabilities up to 3 cm/sec. As the market has transitioned to Type IL cement, which is significantly finer than Type I/II, permeabilities of open cell cellular grout have decreased significantly.
CJGeo has done extensive permeability testing of various cement types and preformed foams to help optimize design of permeable cellular concrete placements.
Uses of cellular grouting
Utility grouting
Pipe abandonment and annular grouting are two of the most common uses of cellular grout in the utility market.
Cellular grout is ideal for utility grouting applications because it its low density results in high pumpability, and reduced buoyancy of carrier pipes.
CJGeo’s ability to batch and pump up to 200cy/hour of material onsite directly from bulk cement also disgns most transportation logistics risk out of high stakes projects.
Load reducing fill
In the geotechnical and structural markets, cellular concrete is an excellent choice for axial and lateral load reduction.
For axial load reduction, cellular’s very low density facilitates building higher with less dead load on underlying structures or compressible soils.
When backfilling walls, CJFill-Ultra Lightweight‘s low unit weight, fast cure and self-supporting properties make it excellent for reducing lateral loads on walls.
Typical Cellular Grout Mixes
Neat Mixes
Neat mixes generally refer to product without aggregate. Occasionally, CJGeo will integrate slag into neat mix cellular concrete.
CJGeo’s staff of geotechnical and materials engineers design project-specific mix designs based on objectives, availability, and costs for each project.
Sanded mixes
Integrating sand into cellular grout significantly increases pumping pressure, but at scale, can be economical for achieving high densities.
CJGeo’s CJFill-Under Water frequently has sand integrated to reduce cost and heat of hydration.
The Advantages
Risk Reduction
Cellular grouting reduces multiple types of risk.
For all projects, logistics risks are significantly reduced due to the high air content, which is generated onsite.
In utility applications, significantly lower placement pressures reduce risks of damage to adjacent structures and utilities.
For structural and geotechnical projects, low density grout reduces the risk of future settlement or wall failures.
Cost Reduction
At scale, CJFill is typically much more cost effective dollar per cubic yard than other lightweight fill or controlled low strength materials.
Time is money, too. CJFill generally designs out most intermediate access points and stages required for utility grouting, significantly reducing project costs.
Increase Speed
Because CJFill cellular grouts are batched onsite at up to 200cy/hour, they are generally significantly faster to perform than traditional materials, such as flowable fill.