01474856

Component

The mechanical behavior of unbound granular materials had proven to be extremely challenging. In the pavement field, as well as in other geotechnical disciplines, these materials are usually treated as elastic or elasto-plastic. The objective of this work is to explore the applicability and potential for a viscoelastic-viscoplastic constitutive theory to characterize unbound granular materials. Such a theory contains as special cases the commonly applied behavior types, it is capable of modeling time-dependence, and can be further compounded to simulate sophisticated effects such as: anisotropy, damage, stiffening in compression, thermal sensitivity, and aging. Laboratory investigation is presented, in which a compacted granular specimen was exposed to a sequence of unidirectional creep and recovery cycles while under constant confinement conditions. Such a testing protocol offers an almost ‘automatic’ separation of the behavior into resilient (viscoelastic) and permanent (viscoplastic) components. Related experimental issues and data preprocessing elements are described in detail. From the measurements it was observed that the material creeps under load and exhibits partial, time-dependent recovery upon unloading. A one-dimensional viscoelastic-viscoplastic constitutive theory was applied as a first attempt to reproduce this behavior. The model was able to simulate very well the observed data trends and magnitudes, and hence deemed potentially generalizable to more advanced conditions.

This paper was sponsored by TRB committee AFP70 Mineral Aggregates.

01470560

13-0903
13-0903

English

19p

2013

Transportation Research Board 92nd Annual Meeting

Digital/other

Figures; Photos; References; Tables

Axle load force; Granular materials; Testing; Viscoelasticity; Viscoplasticity

Geotechnology; Highways; I40: Soils and Rocks

Transportation Research Board Annual Meeting 2013 Paper #13-0903

TRIS, TRB, ATRI

Feb 5 2013 12:17PM