Controlled low-strength material (CLSM) encompasses a variety of fill materials that are primarily used as replacements for compacted backfill. The history of CLSM tracing back to its inception as K-Krete® provides a basis for how test methods came into existence. The American Concrete Institute's (ACI) work assimilating all of the knowledge gained throughout history, including a working definition of CLSM, resulted in a state-of-the-art report which brought this new fill technology to the construction industry. It was ACI who originally recognized the need for test methods to be developed specifically for CLSM.

The testing of CLSM became important, and the role that ASTM Subcommittee D18.15 on Stabilization with Admixtures played in creating standardized test methods is discussed. Background into how these test methods came into existence stems from experiences at the Bureau of Reclamation, the Ohio Ready Mixed Concrete Association, and Pozzolanic Northwest. The history of the current standard test methods for CLSM is rather short but quite important. Five ASTM standards currently exist specifically for CLSM which is just the beginning. Possibilities for additional test methods are explored.