CDF: Controlled Density Fill
CLSM: Controlled Low Strength Material (100 to 200 psi flowable slurry)
Trench backfill is used in any area that may need to be dug up at a later date. This product can be comprised of sand only or sand and different sizes of aggregate. One of the savings to the owner and/or contractor is that there is no need for compacting or vibrating after placement.
Another benefit is that it can be used to pre-level over dug footings that would either have to be filled with compacted aggregate or more expensive concrete. This material has a higher percent of recycled material, typically 87% flyash. Using this material saves time and money on your project.