Sleepers types on main tracks

Kilometres of main tracks by type of sleepers since 2006.
In general, the rails are fixed on a support (sleepers, longitudinal beams, wood pieces) and, exceptionally, on a solid concrete slab.
The sleepers have a double purpose:
to keep the two rails in place and thus achieve and maintain the track gauge imposed;
to support the rails and transfer the loads of the trains evenly to the ballast.
On the main tracks, you will find the following type of sleepers :
Wood : in oak or azobe
Concrete : two generation, old and new
Metal