Moisture influence on the resilient deformation behaviour of unbound granular materials

Abstract

The influence of moisture on the resilient deformation properties of unbound granular materials was investigated based on repeated load triaxial tests. Results showed that the resilient modulus (M_R) decreased with increasing moisture for a relatively low number of load cycles (N) where the deformation behaviour was mostly resilient with a negligible amount of associated accumulated permanent deformation (PD). Modelling attempts on this behaviour were quite satisfactory. Furthermore, the M_R showed an increasing trend with increasing moisture, up to the optimum, when the N was relatively large with a significant amount of accumulated PD. Above the optimum, the M_R generally decreased. Further investigation suggested that moisture aided the post-compaction (PC) and possible particle rearrangement that resulted in the increased PD and increased M_R. The existing model did not work in this case indicating that the effect of PC on M_R should be considered in modelling.

Keywords::

• unbound granular materials
• resilient modulus
• moisture
• repeated-load triaxial test
• modelling

Acknowledgements

This work was sponsored by the Swedish Transport Administration (Trafikverket). The Danish aggregates were provided by the Danish Road Directorate.

Notes

^1. Email: [email protected]