Bridge Deck Waterproofing Using Bitumen Membrane

Product:

The system uses a single-ply membrane with puncture resistance. The membrane is made from highly elastic SBS-modified bitumen and has a non-woven polyester reinforcement.

The upper side is self-protective with ceramic granules; the overlap is finished with a 10-cm polypropylene tissue. The lower side of the membrane is finished with a polypropylene film. The reinforcement is fully impregnated with SBS coating. The homogeneity between compound and impregnation-mixture gives the membrane its extremely high resistance against delamination.

Advantages:

• Light
• Increased resistance to cracking
• Exceptional adhesion on hydraulic concrete
• Easy to weld

Application

1. Concrete surface:

The concrete deck shall be conforming to relevant applicable standards. The concrete surface must be at least 2 weeks old before starting the waterproofing works. The surface must be in good condition, meaning that it must be clean, smooth and even, without any holes and gaps.

2. Surface preparation:

Before applying the primer, check the condition of the bridge deck surface:

• Checking the spots of hydrocarbon
• Checking if all dirt, dust, soil, clay and cement sauce has been removed.
• Thoroughly cleaning the surface, e.g by air pressure
• Verifying that the surface is well dry
• Checking for the gaps, holes, cavities

3. Membrane Installation

Apply the primer with brushes, rollers or spaying tools. Normally it takes about 2 hours for the primer to dry.

The membranes are rolled out, aligned and rolled up again for about ½ of their length. The membrane is welded completely on the surface by the use of high capacity torches.  Immediately the membrane is carefully pressed to the surface by the use of an iron roller to prevent the inclusion of air between the membrane and the surface. Make sure the cross directional overlaps are staggered. The width of the horizontal overlaps should be at least 12cm. The longitudinal overlaps should be 10cm.

Asphalt wearing course

The asphalt wearing course is put directly on the waterproofing. The minimum thickness is 5cm after compacting. The temperature of the asphalt may not exceed 180 Celcious degrees at pouring. During compacting the temperature not exceed 160 degree. Only trucks and vehicles involved with the asphalt wearing course is permitted to the bridge deck area. The contractor has to take care not to damage the  membrane.