Flowable Fill Mixes

Flowable fill mixes are also known as controlled low strength material, or CLSM, lean mix backfill, controlled density fill, soil replacement, K-crete, liquid dirt, or flowable mortar. Flowable fill mixes consists of a mixture of Portland cement combined with aggregates, water, and sometimes chemical admixtures. This material is ideally suited to certain types of projects, primarily for use as a backfill or structural fill when native soil is not suitable, or as an alternative to compacted fill. As water content is adjusted, flowable fill mixes can also be used as a compacted material or mortar.

It’s important to note that flowable fill mixes are not concrete, although Machado Concrete Ready-Mix will deliver it in a ready-mix truck similarly to concrete. Some uses and benefits of flowable fill mixes include:

  • For pavement applications, flowable fill mixes can be easily excavatable when composed of the proper mix.
  • Perfect for bases when year-round availability is required.
  • Flowable fill mixes are ideal for faster backfill.
  • For abandoned tank fills, flowable fill mixes can reduce labor and equipment costs.
  • Ideal for non-corrosive float or footing support.
  • Flowable fill mixes can be color coded for easy identification of utilities or pipe bedding.
  • Self-leveling and self-compacting qualities make flowable fill mixes ideal for bridge conversion.
  • Flowable fill mixes offer a more economical method for filling utility trenches.
  • With changes to the mix, the PSI expectations can be varied for subbase stabilization.

Whether you’re looking to fill your abandoned septic tank or a large contractor filling miles of abandoned pipe, we’re ready to provide flowable fill to your next project. Please Contact us today for more information about our flowable fill mix supply capabilities.


Machado Construction Company, Inc. is Certified in Maryland and Baltimore City as a Minority Business Enterprise (MBE).

Maryland Department of Transportation (MDOT) MBE
Certification #: 88-187

Baltimore City MBE
Certification #: 91-001811  



Have a Question?

Contact Us »