Monotonic and cyclic responses of plastic concrete cores used in embankment dams

The dynamic properties of plastic concrete used as an alternative core in embankment dams were studied. To investigate the specimen's dynamic properties, an extensive series of monotonic and cyclic triaxial tests were done. Bentonite contents 5.5%, 6.0%, 6.5% and 7.0% were selected for the tests. Isotropic and anisotropic initial stress conditions with various principal stress ratios were also considered in this study. Thousands of cycles were applied on some of the specimens, to evaluate their fatigue properties due to seismic loading. A small degradation could be seen but no cracking was observed on the cutting surfaces. All tests were done at a constant temperature of 10 °C simulating a constant temperature inside a dam in cold regions. Shear modulus in the compression region (Gc) and tension region (Ge) are presented for different bentonite content, confining stress, stress ratio (Kc) and loading type. The damping ratio was also presented for different loading states. A regression equation was also derived for determining cyclic and maximum shear modulus (Gmax) of the plastic concrete for different bentonite content as a function of confining stress which can be used in numerical studies. © 2015 ejge.