BCD: A New Tool for Compaction Control

Compacted soil is an essential element in the construction of highways, airports, buildings, sewers, and bridges. Even though soil density is not the most desired engineering property, it is used almost exclusively by the transportation industry to specify, estimate, measure, and control soil compaction because soil density can be easily determined via weight and volume measurements. However, there is a trend towards using the modulus as a compaction control parameter instead of dry density. The reasons are that the most common tool which measures the density in the field requires the use of a nuclear radiation source and that the modulus is used for the design of pavement instead of dry density. The Briaud Compaction Device (BCD) is a new instrument to obtain a soil modulus in only a few seconds. It consists of a cyclindrical top case which includes the display and the electric processing unit, a hollow rod which transmits the load from the handles at the top of the plate, the load cell and a 150mm diameter metal plate below the load cell. This paper describes the tool concept, the field and lab test procedure, the field work reading, the calibration and proposes a recommended procedure to using BCD for compaction project.