Standardized Definitions and Laboratory Procedures for Soil-Cement Specimens Applicable to the Wet Method of Deep Mixing

摘要

The wet method of deep mixing is an important technology used to constructrnexcavation support systems and improve ground beneath embankments and structures.rnHowever, a wide variety of terminology and varying definitions for the same termsrncreate confusion and cause miscommunication among designers, contractors, andrntesting laboratories. Furthermore, different testing laboratories produce quiterndifferent strength test results because there is not a standardized and widely-acceptedrnlaboratory procedure in the United States for preparing, curing, and testing soilcementrnspecimens applicable to the wet method of deep mixing. This paper proposesrnuse of a set of well-defined terms, including volume ratio, cement factor, cementrnfactor in-place, cement content, water-to-cement ratio of the slurry, and total-waterto-rncement ratio of the mixture. Relationships among these terms are provided inrnforms that can be used to control construction operations and determine mixturerncomponent quantities for laboratory testing. In addition, a laboratory procedure isrndescribed that controls the principal factors producing variability in test results. Thernlaboratory procedure is applied to five easily-mixed soils, and the unconfinedrncompressive strengths of the mixtures correlate more strongly with total-water-tocementrnratio than with cement factor, cement factor in-place, or cement content.