1. Macroscopic Behavior of Expansive Clay Minerals in the Crystalline Swelling Regime
William J. Likos, Department of Civil and Environmental Engineering, University of Missouri, Columbia MO 65211
Crystalline swelling is a process whereby expandable 2:1 phyllosilicates sequentially intercalate one, two, three, or four layers of H2O between the mineral interlayers. We aim to explore how these nano-scale volume changes upscale to macro-scale volume changes and pressure generation for bulk clay systems. ?
Interlayer Hydration
Macroscopic Response
Experiments are being conducted to determine relationships among interlayer water potential, bulk volume change, confining pressure, and mineralogy on crystalline swelling upscaling processes.
We are currently examining influences of particle fabric on upscaling response. A microstructural fabric model has been developed to conceptualize interactions among various levels of pore structure. Our next goal is to develop 3-D constitutive surfaces to define relations among interlayer water potential, volume change, and swell pressure generation.