GEOLAB - Transnational Access project HSRTSUB - Resilient behaviour of stabilized and conventional high-speed's rail track subgrades under different drainage conditions and seat loads

In this study, the shear strength of track ballast material is evaluated by testing different types of track ballast specimens, which was conducted in a Large-scale Triaxial Apparatus at ZAG ) that has a shear area of 40 cm x 40 cm and can accommodate specimens up to 80 cm high. It enable loading of specimens in simple shear mode.

The tests, which were conducted within HSRTSUB project, include two different types of ballast, the fouled ballast samples and the clean ballast samples, and two different specimen preparation techniques (with and without compaction). The normal stresses used cover a wide range from 50 to 400 kPa.

The European standard EN13450 "Aggregates for railway ballast" was used. This standard specifies the properties of aggregates obtained by processing natural, manufactured or recycled crushed unbound aggregates for use in the construction of the upper layer of railway track. For the purposes of this standard, the aggregate is referred to as track ballast.

Tests were conducted under unsaturated conditions with two types of lightweight materials:

- fouled ballast aggregates and

- clean ballast aggregates