Installation principles
Combinations between RENOLIT ALKORPRO “pre-applied” and “post-applied” geomembranes make it possible to waterproof tunnels with a single base material (PVC-P). In cut and cover tunnels with or without a retaining wall, the RENOLIT ALKORPRO waterproofing system is a durable, reliable and easy-to-install solution.
Cut and cover tunnels without retaining wall
On the slab, the “pre-applied” RENOLIT ALKORPRO geomembrane is installed on the lean concrete before the concrete is poured.
On the roof and on the vertical walls, the “post-applied” RENOLIT ALKORPRO geomembrane is installed on the concrete structure after its completion. Each length of geomembrane will be installed in one piece over the roof and the side walls.
The overlap between the rolls of RENOLIT ALKORPRO geomembrane will be sealed by heat welding or by gluing.
Cut and cover tunnels with retaining wall
For the side walls, the “pre-applied” RENOLIT ALKORPRO geomembrane is installed before pouring the concrete, on a lost formwork or directly on the retaining wall with an anti- puncture geotextile.
The geomembrane is fixed to the support by means of fixing roundels or by means of a temporary fixing at the top (in the case where the retaining wall is separated from the structure of the tunnel.)
On the roof, the “post-applied” RENOLIT ALKORPRO geomembrane is placed with its fleece against the concrete.
The overlap between the rolls of geomembrane will be sealed by heat welding or by gluing.
Cut and cover tunnel with diaphragm wall (relatively watertight structure)
In this type of structure, the diaphragm walls do not have a waterproofing coating. However, they are treated to block water penetration, by injection and caulking of the segment joints.
On the slab, the “pre-applied” RENOLIT ALKORPRO geomembrane is installed on the lean concrete before pouring the concrete. A PVC anchor profile is installed in the diaphragm wall, through a notch made with a saw. The end of the profile is sealed in the diaphragm wall using CEM805 glue and the other end is heat welded with the RENOLIT ALKORPRO geomembrane.
On the roof, the “post-applied” RENOLIT ALKORPRO geomembrane is installed with its fleece against the concrete.
On the slab
The “pre-applied” RENOLIT ALKORPRO geomembrane must be installed on a flat, clean and smooth substrate, free from protrusions and sharp edges. The fleece surface needs to be oriented to the concrete to pour. The rolls must be positioned correctly in accordance with the following detail.
On the slab
“Pre-applied” on side wall
On side wall without retaining wall, the “pre-applied” RENOLIT ALKORPRO geomembrane is stapled to a reusable wooden formwork, before concreting. On a side wall with retaining wall, the “pre-applied” RENOLIT ALKORPRO geomembrane is installed on the retaining wall using temporary fixings or fixing roundels.
Fixing the “post-applied” RENOLIT ALKORPRO geomembrane
The “post-applied” RENOLIT ALKORPRO geomembrane is fixed to the concrete structure by means of retaining plates nailed through the geomembrane. The fixations must be positioned only on the longitudinal edge of each roll, so that the adjacent roll can overlap the fixations on its free edge. The rolls of RENOLIT ALKORPRO geomembranes must have an overlap of at least 100 mm.
