A study to improve equipment and procedures for triaxial testing of coarse grained materials

A new procedure and some equipment are developed to remove a sample o f coarse grained materials from the compaction mould and to encapsula te it in rubber membrane for triaxial testing. The samples seems to m aintain the structure as compacted quite well. The repeated load tria xial equipment used at NTNU/SINTEF has been modernised and improved. The equipment for registration and control has been changed and the m easurement results are now more reliable. A new loading procedure is developed to provide parameters for a new hyperelastic model for the behaviour of granular materials. This model is belived to give a more realistic estimation of stresses and strains than obtained by the li near elastic model and it provides an improved basis for the predicti on of permanent deformation in granular layers of pavements.