Antonina Hochuli

Duration : 01.01.2021 – present

Supervisor : Professor Eugen Brühwiler

Doctoral Student : Antonina Hochuli

Research introduction

The research project focuses on the improvement of fixed railway track systems by the application of novel material UHPFRC (Ultra-High-Performance Fibre Reinforced Cementitious composite material). Since the fixed railway tracks are part of the bearing structure of infrastructure such as a tunnel or bridge, the same service duration at least of 100 years should be guaranteed.

The Ultra-High-Performance Fibre Reinforced Composite material (UHPFRC) is a cementitious material which has a compressive strength of more than 150 MPa and a tensile strength of more than 12 MPa while developing pronounced strain-hardening (given a certain volume of fibres) and strain-softening behaviour in tension. UHPFRC also has a high fatigue resistance, very low permeability for fluids providing thus high durability.

As a result of the proposed application of UHPFRC, the dimension of structural members of fixed railway systems will be reduced and therefore shorter rail fasteners will be required. To achieve this goal, the pull-out resistance of UHPFRC for short fasteners subjected to cyclic loadings will be determined by means of numerical tests.

In the framework of this work, the laboratory tests will be replaced by numerical simulation. The numerical models of building material will be calibrated using the results of already performed laboratory tests. Using these numerical models, the pull-out resistance of short fasteners in UHPFRC will be determined and the behaviour of UHPFRC subjected to quasi-static and cyclic loadings will be investigated.

As one of the main results of this research work, the pull-out behaviour of UHPFRC in the high cycle fatigue domain (N≥106) will be described in detail.

Furthermore, the neu high performance fixed railway track systems will be developed and validated.