CJFill Load Reducing Fill
CJFill is a a cement-based load reducing fill. With unit weights as much as 1/7th the density of other self-consolidating fill materials, CJFill lets you build structures lighter.
Axial Load Reduction
Axial (vertical) load reduction is the most common use for CJFill. Typical applications include:
- building over compressible soils
- raising grades after ground improvement such as stone columns
- reducing loads over aging underlying utilities
- optimizing deep foundation designs by reducing dead loads
Calculating
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 load reducing fill. 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 |
Load Reducing Fill Design Assistance
CJGeo has a staff of preconstruction and operations experts who can assist in designing and planning load reducing 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 load reducing fill? Also not a problem. To get started, give us a shout.
Speak With An Expert
Facing a challenge? 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.
