Water stops are used in joints such as construction joints,expansion joints where the concrete structure which is retaining or faced to hydrostatic pressure to avoid leaks or penetration to other side.
SUPER CAST PVC WATER STOPS
Super cast PVC water stops are extruded from a high grade PVC compound that has been formulated to give excellent flexibility & longevity characteristics. These are designed to provide an integral sealing system for movement and construction joints in concrete cast in situation. These joints typically occur in the following types of structure.
1) Water retaining structure
Reservoirs, water towers and sewage tanks
Dams, culverts, canals and spillways
Swimming pools
Bunded areas surrounding liquid retaining tanks
2) Water excluding structure
Basements and underground car parks
Tunnels and subways
Abutments and retaining walls
Roof decks and podium areas
Super cast water stops are available as,
1) Straight lengths
2) Factory produced intersections
3) Factory prefabricated segment of a network to minimize site jointing
Water stops must be installed so that they are securely held in their correct position while the concrete is being placed. Concrete must be fully compacted around the water stops to ensure that no voids or porous areas remain. Where reinforcement is present, an adequate clearance must be left to permit proper compaction
When used on ground slabs where the water stop is supported on blinding, rearguard profiles usually require no fixing. Lay the water stop centrally over the line of the joint to be formed.
The choice of the width and thickness of water stops is largely depend on concrete thickness, the position of reinforcement, aggregate size and completing of the pour.
CLASS U2
This shall be a wood float finish. Floating shall be done after the initial set of the concrete has taken place and the surface has hardened sufficiently. Concrete shall be worked no more than is necessary to produce a uniform surface free from screed marks.
CLASS U3
This finish shall be a hard smooth steel-troweled finish. Troweling shall not commence until the moisture film has disappeared and the concrete has hardened sufficiently to prevent excess Latinate from being worked into the surface. Surface shall be troweled under firm pressure and left free from trowel marks. All surfaces, which are not to be covered with a further finish, will be U3 finish. All surfaces on which further finishing screed or treatment are to be applied, will be U2 finish.