Document Archives

Controlled Low Strength Material

• ID:

  1973

• ESCSI:

  6543.001

• Author:

  Smith, Anne

• Publication Name:

  Concrete Construction

• Type of Publication:

  Article

• Publisher:

  Aberdeen Group

• Dated:

  1991

• Issue/Volume:

  May

• Other ID:

• Page(s):

  389-398

• Reference List:

  Y

• Abstract:

  This material has several generic names including flowable fill, lean-mix backfill, unshrinkable fill, flowable mortar, and controlled-density fill (CDF). But the name given to it by American Concrete Institute (ACI) Committee 229 seems to be gaining the most acceptance–controlled low-strength material (CLSM).CLSM is not a concrete nor a soil-cement but it has properties similar to both. It’s a fluid mixture made of portland cement, water, and fine aggregate or fly ash or both. Sometimes it also contains an admixture. The consistency of CLSM is like that of a slurry or lean grout, yet several hours after placement the material hardens enough to support traffic loads without settling. Typical 28-day compressive strengths range from 50 to 200 psi–more than the strength of most compacted soil or granular fills. Densities range from 115 to 145 pounds per cubic foot.