Expensive and time-consuming maintenance operations are routinely performed to preserve the ballast mechanical properties in railway lines. Binding agents are used for ballast stabilisation. Four different additives based on bitumen, organosilane, lignosulphonate and polyurethane are investigated in the laboratory by means of repeated load triaxial tests. The parameters that are directly relevant for use in railway structures are assessed. Each binder type significantly influences both the resilient modulus and the resistance to permanent deformation of the treated specimens. The ballast mechanical properties can be conveniently modified, thus being beneficial to track stability and railway maintenance programme
