A study to improve equipment and procedures for triaxial testing of coarse grained granular 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 seem to ma intain 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 material mode l for the behaviour of granular materials. This model is believed to give a more realistic estimation of stresses and strains than obtaine d by the linear elastic model and it provides an improved basis for t he prediction of permanent deformation in granular layers of pavement s.