Controlled low-strength materials (CLSM) are self-consolidating, cementitious materials used primarily as a backfill in place of compacted fill. CLSM can be placed by chutes, conveyors, buckets, or pumps, depending on the application and its accessibility. Internal vibration or consolidation is not required because the CLSM consolidates under its own weight. Although it can be placed year-round, CLSM should be protected from freezing until it has hardened. Curing methods specified for concrete are not considered essential for CLSM.

This eLearning course, Controlled Low-Strength Materials Fundamentals, is available online.