Preventing Water Leakage through Construction Joints in RCC Water Contact Structures

Preventing Water Leakage

through Construction Joints

in RCC Water Contact Structures

PREFORMED COMPRESSIBLE WATERSTOPS

Overhead Water TankSources of Water Leakage

Construction Joints

Sump Tank, Swimming Pool, Sewage Treatment Plants………..

Sources of Water Leakage

Horizontal Construction Joint

Inclined Construction Joint

Construction Joints

Construction Joints

Vertical Construction Jointin Final Roof Slabs which cannot be cast in one go

Water may Leak through the joint shown by dotted line

Construction Joint

Vertical Construction joint in BasementSources of Water Leakage

Construction joint

Basement Construction Joints

Sources of Water Leakage

Wall Floor Joint and all around columns

Construction Joints are present in…..

Overhead Water Tanks Swimming Pools Basements Underground Reservoirs Water Treatment Plants Sewage Treatment Plants

Vertically Held Vibrator unable to consolidate concrete here hence

Construction Joint gap

Water enters here

Typical Construction Joint for Basement

The Nagging Problem

Leakage of water through the improperly executed Construction Joint

Swimming Pool Leakagefrom bottom joint This is a movie file. Please wait a few seconds. It will play automatically.

Basement LeakagePlease observe leakage around column base when ground water table rises

This is a movie file. Please wait a few seconds. It will play automatically.

Stopping Water Leaks

Engineers have tried various methods to solve this problem

- during Concreting - after Concreting

Painting with Epoxy

Painting with epoxy bonding agent

Question: How can a gap get filled with a coat of epoxy ?

Debonding is not the problem, existence of a gap is the problem

Hence Unsuccessful method

PVC Waterbar sketch

The next slide is a 20 second movie slide. Kindly wait a few seconds for it to start playing.

Please go to the next slide only after concrete pours onto the PVC water bar.

It shows problems that a PVC waterbar can create and after that, contrasts it with a preformed waterstop.

Thank you.

PVC Waterbar

PVC Waterbar Problems 1

Half of it has to be inserted during concreting

Generally difficult to insert due to obstruction by rebar

Folds over during next lift of concreting and forms a tunnel in which water can leak

Never bonds with concrete

PVC Waterbar Problems 2

End to end should be spliced with PVC Welding equipment which is generally not available at site

Different sizes of strips have to be maintained to resist different heads of water. Chances of mix-up are very high

After Concreting

Grouting into Construction Joints

Generally unsuccessful

Expensive, tedious, time consuming

The Right Approach

SYNKOFLEX Compressible

Flexible

Waterstop

SYNKOFLEX Compressible Flexible Waterstop

SYNKOFLEX Compressible Waterstop

Waterstop Application

A Simple SolutionThis is a movie file. Please wait a few seconds. It will play automatically.

The next slide is a 15 second movie slide. Kindly wait a few seconds for it to start playing.

Please note how concrete flows all around the Synkoflex and seals the joint with Synkoflex acting like a gasket. Such a compressed seal will never

fail.

Laying Synkoflex cross sectional view

How to use - 1

How to use – 2

How to use - 3

Application of SYNKOFLEX Waterstopin Basement Construction Joints

a) Wrap Synkoflex around column base.b) Also stick to wall along the perimeter of basement

FOOTINGS RAFT SLABRETAINING WALL

Application of SYNKOFLEX Waterstopin Final Roof Joint

After first phase of concrete pour, stick Synkoflex as shown and then continue with the second pour to get a 100 percent leak free

joint

WATERSTOP

Vertical joints – Nail the SynkoflexThis is a movie file. Please wait a few seconds. It will play automatically.

Pipe JointsThis is a movie file. Please wait a few seconds. It will play automatically.

Laying Synkoflex in basement joints

This is a movie file. Please wait a few seconds. It will play automatically.

Synkoflex

Single component, self sealing compound

Packed between two self release wrappers

Bonds to cured concrete

Fuses with fresh concrete during hydration

Properties of Synkoflex - 1

Environmentally Safe

Can be used for drinking water tanks

Does not depend on chemical action, swelling, oxidizing for its action

Flexibility of Synkoflex is forever

Properties of Synkoflex - 2

Never shrinks, cracks or dries out

Inert to acids, alkalies and sewage

Can be stored indefinitely

Can be laid using unskilled labour

Need not be laid when concrete is green

Effectiveness

Designed to resist water head of 20 mtrs (65 feet) of water when placed in properly designed and compacted M 20 grade concrete

Tests have confirmed that Synkoflex is effective upto 32 mtrs (105 ft)

TRFI test confirms unequivocally for 20 mtrs water head

Effectiveness

In extreme cases, can be used even under standing water

Used since 1968 in

Tunnels Potable Water reservoirs Sewage Treatment Plants Fish Hatcheries Waste Water Treatment Plants Swimming Pools Water Tanks

Where else to use

Joint between Old roof and new roof Joint between Column and Floor when new

floor is being cast Basement Floor (Raft Slab) Horizontal Joint Basement Wall Vertical Joint

Where else to use

Topmost roof cast in two pours

Any joint between Old Concrete and new concrete provided thickness of concrete member is more than 150 mm

Pipe intrusions in Basement Retaining Walls

Where not to use

Expansion joints

Tanks which store petroleum based liquids

Case Study – Reservoirs

200 reservoirs built by Govt. of Karnataka

No construction joint is leaking

Case Study – Old,New RCC

Landmark building in Karnataka

Was required to abut new roof to old roof

About 150 mtrs of Synkoflex used

No leakage anywhere

Case Study – Swimming Pool

Swimming Pool built on fifth floor roof by leading developer in Bangalore

No leakage through construction joint

Case Study - Basement

Leading Jeweller in Chennai

Double basement

Synkoflex used in joints

Basement is bone dry

Synkoflex Packing

Cross section 20 mm x 20 mm

1 mtr strips x 25 nos per box

The Low Cost of Success

For a Water treatment plant measuring 8 mtr x 32 mtr x ht 6 mtr volume about 1.5 million ltrs of water

Joint length assumed as about 200 mtrs depending on concreting scheme

Cost of water tight joints is about Rs. 70,000 which is a negligible cost of the total project cost (Rs. 50 lakhs) 1.4 %

TESTS

Successfully tested by CFTRI, Mysore for potable water safety

Successfully tested by TRFI for resisting water head of 20 mtrs

Conclusion

Compressible Waterstop enables a 100 percent watertight seal

SYNKOFLEX Waterstop is a permanent solution to stop leakage through construction joints

THANK YOU