Controlled low-strength material (clsm) is defined by the american concrete institute as having a 28-day compressive stength less than 1, 200 psi. Its primary ingredients are portland cement, fly ash, and filler aggregate. Although clsms have been in use for a number of years, confusion about their construction benefits and economic savings remains. The principal use of clsm has been as a controlled-density fill (cdf) in place of conventionally placed backfill. A method for determining the cost of clsm-cdf and how it can affect a contractor's total construction costs is described. General technical information for the manufacture and testing of clsm in the laboratory and in the field is cited. A small sample of ready-mixed concrete producers indicates the need for dissemination of information about clsm. This paper appears in transportation research record no. 1315, Culverts and pipelines: design, monitoring, evaluation, and repair 1991.
Abstract