Investigation of Cement Modification of Granular Base and Subbase Materials Using Triaxial Frequency Sweep Characterization (05-1371)
Curtis F. Berthelot, University of Saskatchewan, Canada
Anna Anthony, Saskatchewan Department of Highways & Transportation
Tom Scullion, Texas A&M Transportation Institute
Dave Luhr, Portland Cement Association
Aggregate materials are the primary road strengthening system used today. However, aggregates are also a non-renewable natural resource, particularly high quality aggregates. Many highway agencies worldwide are experiencing depletion of high quality aggregate sources and are now forced to consider the use of marginal aggregates for road building projects. However, lower quality aggregates may require modification in order to provide adequate field performance. This research investigated the effect of cement modification on typical granular materials used for road construction. The characterization methods employed in this research included moisture susceptibility, unconfined compressive strength, and triaxial frequency sweep testing. Specimens were prepared with and without cement at optimum standard Proctor moisture-density conditions. As well, a duplicate set was characterized across all tests after moisture saturation to quantify the effect moisture has on various aggregate systems. Statistical analysis was employed to quantify partial correlation coefficients between independent and dependent variables, across the material systems. The test results showed a difference in the behaviour of unmodified aggregate materials, particularly with respect to fines content and crush fraction. The test results also show a consistent improvement in the performance of all cement-treated granular materials in term of both mechanical and climatic durability.