2019 – Hydrophilic Waterstops in Dam Engineering

Sam Taubert, Peter Buchanan, Steven Fox

Hydrophilic waterstops have been used in in-situ concrete for convenience, cost savings and in locations where installing an alternative form of waterstop has not been practical. The waterstop is often preferred to traditional PVC waterstops given its simplified construction methodology whilst still providing seals of up to 50 m of head. The principle of the performance of the waterstop is that it is capable of expanding upon absorption of water to seal the joint, making it ideal for gap variation. However, recent experience has indicated that this ability to expand can generate sufficient forces to generate localised failure of concrete including cracking, spalling, and exposure of reinforcement and ultimately failure of joints.

This paper reviews examples of poor detailing of hydrophilic water stop installation, the conditions leading to the failure of the concrete, how these compare to the waterstop manufacturers installation recommendations and discusses the design approach to using hydrophilic waterstops and its shortcomings in dam spillway engineering.

Buy this resource