CJFill Self Consolidating Fill
Self consolidating fill is an engineered fill material designed to not require compaction, so speeds up construction, reduces costs, and eliminates chances of future settlement due to fill consolidation. CJFill is a a cement-based load self-consolidating fill. Generated at up to 200CY/hour onsite, CJFill lets you build faster. With unit weights as much as 1/7th the density of other self-consolidating fill materials, CJFill lets you build structures lighter.
Compaction Elimination
The primary purpose of self consolidating fill is eliminating the need for compaction, and of future settlement due to poorly controlled compaction.
Building over compressible soils, such as this bridge replacement project in Baltimore. Three different bridges were rebuilt at up to 6′ higher than the original structures. Using common borrow would have resulted in significant settlement due underlying compressible soils. CJGeo placed nearly 30,000 cubic yards of 25lb/cuft CJFill-Ultra Lightweight up to 20 feet deep to eliminate all anticipated settlement.
Ground improvement is excellent for increasing the capacity of soils on sites. But sometimes, it can’t quite get to the optimal capacity. In this case, utilizing low density material that doesn’t require compaction to build up sites after ground improvement is really helpful. On this project in Norfolk, Virginia, CJGeo installed 25lb/cuft CJFill-Ultra Lightweight self consolidating fill to bring a site up as much as 8 feet after stone column installation.
Backfilling irregularly shaped excavations can be tricky. Eliminating the need for compaction eliminates the chances of settlement due to consolidation of poorly-controlled fill.
Lateral Load Reduction
As a self-supporting mass once cured, CJFill can help eliminate active earth pressure. As a liquid, CJFill imparts lateral pressure on a structure during installation that’s calculated as hydraulic head. Unlike structural concrete form pressure calculations, there is no internal friction contribution from aggregate to factor head calculations. For example, a 2′ deep pour of 25lb/cuft material would have a hydraulic head of 50PSF at the base of the pour. Once the material sets in a few hours, it stops imparting any lateral loads.
CJFill is incompressible and inelastic. Therefore, soils behind the mass need to be either retained or laid back so that they do not transmit any active earth pressure to the mass of CJFill. Slope material will drive the angle, but 1H:1V to 2H:1V slopes are most common.
Physical Properties
There are four broad classes of CJFill material that don’t require compaction. The two most common are CJFill-UL (Ultra Lightweight) and CJFill-HP (High Permeability). This table shows typical properties of both materials. Note that while CJFill-UL is freely-draining, its permeability is lower than CJFill-HP’s.
| Property | Minimum | Maximum |
| Wet Cast Density | 25lb/cuft | 35lb/cuft |
| Cured Density | 16lb/cuft | 32lb/cuft |
| Compressive Strength (ASTM C495 @ 28 days) | 25psi (3.6KSF) | 200psi (28.8KSF) |
| Permeability (ASTM D2434 modified) *CJFill-HP only* | 2 cm/sec | 0.5 cm/sec |
No Compaction Fill Design Assistance
CJGeo has a staff of preconstruction and operations experts who can assist in designing and planning self consolidating fill projects. Want to talk to a geotechnical PE? Not a problem. Want to talk to someone who’s supervised the installation of hundreds of thousands of cubic yards of self consolidating fill? Also not a problem. To get started, give us a shout.
Speak With An Expert
Facing a challenge that could be solved with self consolidating fill? 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.
