In order to understand the behavior of large sections made with a grout, mortar, or concrete containing expansive cement, a three-phase laboratory program was initiated. The first phase was the study of pumpable mortars, the results of which are reported herein. The remaining two phases include concrete and grouts, respectively, and are presently planned for completion at the Concrete Laboratory, U.S. Army Engineer Waterways Experiment Station (WES). The principal purpose of the study of pumpable mortars was to examine the effects of mixture ingredients and proportioning on the physical properties of the mortar. Of secondary concern was the definition of the expansive potential of any mixture containing expansive cement and the effect of specimen size and shape on expansion.