Predicting permanent deformation behaviour of unbound granular materials

Publisher's full text

To reliably predict the permanent deformation behaviour of unbound granular materials (UGM) in a pavement structure, the material parameters of the constitutive models used in design should be evaluated using a multi-stage (MS) loading approach. This paper investigated the prediction of the accumulation of permanent strain in UGM using some current models, extended applying the time-hardening approach, based on MS repeated load triaxial tests (RLTTs).

The material parameters of these models were optimised for five different UGM used in pavement construction using the MS RLTT data with a specific set of stress levels. With these models, the accumulations of permanent strain in the same materials for MS RLTTs with a different set of stress levels were predicted. Using this approach, three out of the four models performed very well, which may be further developed for field conditions for better prediction of rutting.



Vision Zero for Sustainable Road Safety in the Baltic Sea Region

The conference Vision Zero for Sustainable Road Safety in the Baltic Sea Region is held i Vilnius, Lithuania. VTI is part of the organisation committé and also one of the speakers.



VTI participated in conference on electric roads

Systems with electrified roads are a relatively new concept and many projects have been launched in recent years. To stimulate the transfer of knowledge and collaboration, the Research and Innovation Platform for Electric Roads arranged its second...


ADAS&ME is tackling the interaction between people and technology

ADAS&ME is a major EU project focused on automation, the human condition and the human environment. The budget is EUR 9.6 million and VTI is the coordinator.


Users contribute to the development of train simulators

Apart from advanced driving simulators, VTI has developed several variations of train simulators which are used for training, education and research. In recent years, interest has increased drastically among major actors in the railway sector, and VTI has...


VR study to contribute to a better working environment for bus drivers

A study where bus drivers test autonomous driving in a VR environment may contribute to a better working environment with reduced stress on the driver and safer driving.


Non-native plant species spread via transport systems

Researchers at VTI have compiled a report on non-native invasive plant species in Sweden and how they spread via transport systems.


EU-project VIRTUAL: improving road safety with virtual crash tests

Crash tests are used to improve safety on roads. Therefore the EU now funds a research project to develop virtual methods of crash testing. VTI coordinates the project, called VIRTUAL. The project now invites experts interested in Human Body Modeling to join...