Cellular Concrete—What is it?
- Foam Cement
- Aerated concrete
- Lightweight cellular concrete (LCC)
- Low Density Cellular Concrete (LDCC)
- Low Density Controlled Low Strength Material (LD—CLSM)
- Lightweight Insulating Concrete
Cellular Concrete is produced by substituting some or all of the aggregate particles with a uniform cellular structure of air cells (voids). The air cells are produced mechanically using special liquid foam concentrates and a foam generator, creating a product that we call Preformed Foam. It is the consistency of shaving cream. Foam concentrates must meet the standard ASTM C869 and C796 for use in cellular concrete.
The Preformed Foam is then mechanically blended with a slurry mix consisting of cement, fly ash, water and rarely some ag-gregates. This causes the base mix to dramatically increase volume and reduce density. The special air bubbles hold their shape until the cement sets trapping the voids in the material and creating a low density remarkably strong material. The density and strength of the material is a function of the mix design which can change with each and every job.
So why would I spend time on this?
The simple answer is time and money. As a contractor you are in business to make a profit and feed the many families that rely on your success. This product when used correctly helps to make that possible. Contractors have the ability to use the proper-ties of this product in their bids or as a Value Engineered option in many ways that make sense. A recent example saved over $2M on a highway project in California. This product can be a simple replacement for more expensive fill. Or, and even better, a structural replacement revising the entire design and saving huge money and time for your project. See the project examples page for some ideas that may work for you.
Why would I use this product on my project?
Simply the answer is one of these: Lightweight – Highly Flowable – Inexpensive Fill – Geotechnically Structural
Cellular concrete has remarkable properties. Designers/Owners that understand the benefits of a lightweight, extremely strong product, that is poured into place and is relatively inexpensive, reap huge benefits. The cost and time savings for their projects can be huge.
For example Cellular Concrete used as a lightweight fill to reduce settlement can be performed for about the same cost as sur-charging in only a tiny fraction of the time with no impact on adjacent structures.
Properties of Cellular Concrete
- Low Density/Lightweight – Do you have surcharging on your project? Is settlement anticipated? Adjacent structures? Is this a design build and loads are a concern in the design? If so then this product can help. Simply you can save many months of waiting time over surcharging with technically the exact same solution/Factor of safety for the final property owner. The months saved on your manage-ment is enough to justify evaluating this option. Load Balancing is the term used to describe the removal of heavy existing soils and replacement with lightweight fills to “balance” the weight of the new construction. Simply no new weight, no settlement!!
- Cellular Foam Concrete has High Load Bearing Capacity – Lightweight, yet stronger than soils or compacted fills. When placed beneath structures, typically for load reduction you can then also redesign your foundation for a dramatically stronger subgrade that is non-expansive.
- Permeable and Non-Permeable – Cellular Foam Concrete is more flexible and helps to solve specific construction challenges by choosing either the permeable or non-permeable options.
- Easily Pumpable – High air content makes Cellular Foam Concrete easy to pump long distances at low pressures. The air bubbles act like ball-bearings in the mix. This sounds nice but the real benefit is to avoid excavating additional access pits to fill the pipe. When used for pipeline fills the lengths can easily extend thousands of feet. The cost of cellular concrete is typically less than the cost of a ready mix product and the cellular price includes installation. Most ready mix products see extreme pressures when pushed more than 200’ and care should be taken when using these products for pipeline fills.
- Highly Flowable – Self-leveling and will flow into and fill any void. This reduces/eliminates and discussion of compaction. The in-spector typically just takes a sample, watches for a few minutes and takes off.
- No Compaction needed – No compaction is necessary when using Cellular Concrete. Reducing the cost of inspection if the contract has the contractor performing the QC.
- Insulating Properties – Cellular Foam Concrete provides good to great insulation qualities. Does the pipeline have an insulated a layer increasing the cost of the pipe. Then check out insulated backfill instead, good for hot or cold. Since you are already backfilling the inexpensive price of cellular backfill (depending on the quantity) may provide the same properties and a benefit to the installer.
- Absorbs Energy- – As cellular concrete is crushed during impact, resistance increases and kinetic energy is absorbed.