Intelligent Compaction Implementation: Research Assessment

The objective of this project was to provide a qualitative assessment of the Minnesota Department of Transportation's Intelligent Compaction (IC) Specifications. IC is an attractive approach to evaluate the compaction quality because it involves continuous and instantaneous evaluation of the soil through machine-drive power or drum vibration monitoring. Four construction sites utilizing IC were visited: (1) TH 36 in North St. Paul, involving both granular and nongranular soils; (2) US 10 in Staples, with granular soil; (3) TH 60 in Bigelow, with nongranular soil; (4) US 10 in Detroit Lakes, involving both granular and nongranular soils. The report integrates comments from the four site visits and provides an interpretation on the use of IC at each site. As the technology now exists on the equipment used at these locations, IC provides only an index, which is specific to the conditions associated with a particular site. An interpretation of comments provided the basis for the following recommendations: Use light weight deflectometers (LWD) for quality assurance of stiffness; Establish a procedure to determine the target LWD value; Eliminate calibration areas (control strips); Simplify IC data evaluation and presentation; Calibrate the IC roller and related transducers; Support development of alternative IC methodologies; Simplify or eliminate moisture corrections.