Waterstops or Waterbar
Waterstops or waterbars are flexible tape like elements of a concrete structure that prevent the passage of water through concrete joints. Concrete joints are most liable to seepage. They are designed as fluid tight diaphragm embedded in or running along the joints. The join is as watertight as the waterbar that join them.
For sizeable concrete structures like retaining walls, basements, reservoirs and tunnels joints are inevitable. It can be construction or expansion joints or both. Joints in direct contact with water need the protection of a waterbar. They are hydrophilic or impervious strips cast into the concrete at the joints to prevent the passage of water.
Waterstops placed centrally provide efficient barrier to penetration of water from either face of slab or a wall. It should be carefully fixed in the formwork before concreting. On the other hand externally placed waterbars are easy to fix by nailing through “outboard” flange. These prevent passage of water from outside of the structure. External waterstops are usually used in piled wall basement construction.
The primary functions of a waterbar is to act as a waterproofing seal in the joint. It allow movement of two sections independently of each other without restraint (free of tension). PVC waterstops are always be joined by welding by heating and never by lapping. Waterbars are supplied in rolls.
Applications of Waterstops or Waterbars
Waterstops used in construction industry provides waterproofing. Waterbar is used in water and transportation industry to improve the quality of construction. Common structural applications are in:
Water and sewage disposal projects.
Dams, channels, tunnels and tanks.
Box culverts and locks.
Primary and secondary containments structures.
Bridges and decks abutments.
Wall and slabs.
Basements and foundations