Date of Award
Master of Science
Civil, Construction, and Environmental Engineering
David J. White
Contractors and engineers in the earthwork engineering industry desire a more effective pre-bid and QA/QC tool that links moisture-density-compaction energy relationships with shear strength and stiffness properties for compacted geomaterials. The Compaction Forecasting Expert Database (CFED) is being developed by Caterpillar Inc. and the Center for Earthworks Engineering Research (CEER) to predict the compaction behavior of geomaterials and provide recommendations for earthwork construction. However, in the current version of CFED, the Proctor test is the only laboratory method used to evaluate compaction behavior of geomaterials, and it does not provide shear strength and stiffness properties of compacted geomaterials. The goal of this research was to improve the CFED by linking moisture-density-compaction energy relationships with shear strength and stiffness properties to predict and evaluate the compaction performance of geomaterials. The objectives of this study were to expand the CFED with more lab testing data; evaluate two laboratory tests, the Iowa K and gyration compaction tests, to quickly determine compaction behavior; and evaluate relationships between moisture content, density, compaction energy, shear strength, and stiffness parameters of geomaterials. A range of non-granular and granular geomaterials were tested to evaluate the performance of the Iowa K test and a gyratory compaction test equipped with a pressure distribution analyzer (PDA). The important outcomes of this research are that (1) the Iowa K test and gyratory compaction test with a PDA can simply, quickly, and inexpensively simulate field conditions, determine compaction behaviors, and test the shear strength and stiffness of compacted geomaterials; (2) moisture content and dry unit weight can significantly influence shear strength and stiffness properties of non-granular compacted geomaterials; and (3) gyratory compaction tests with a PDA results showed that the maximum aggregate size can significantly influence the shear resistance of granular geomaterials. Owners, contractors, and taxpayers will benefit from this research because the improved CFED will be a more cost-effective tool for predicting and monitoring the compaction performance of geomaterials.
LI, CHENG, "Using the Iowa K test and the gyratory compaction test to improve the Compaction Forecasting Expert Database" (2013). Graduate Theses and Dissertations. 13394.