HYDROPHILIC/BENTONITE/ASPHALT RUBBER - WATERPROOFING.

These systems are all installed after the first concrete placement has occurred, with the materials attached directly to the first half by a variety of methods. The waterstop is supplied in rolls in lengths of several hundred feet and the material is adhered to the substrates by a variety of methods as recommended by the manufacturer.

Typically, the concrete does not need to be cured completely, as this would interfere with the placement schedule of the concrete. Substrate preparation is usually minimal, ensuring that there are no form release agents, fins, or other protrusions that can damage or puncture the waterstop during installation. Attachment is completed by a variety of methods, some as simple as nailing the strip to the concrete to hold it in place temporarily until the second half of concrete placement occurs.

It is imperative that the hydrophilic and bentonite materials are not left exposed to rain-fall before concrete is placed. If this occurs, the material will swell and lose all its capability to seal the joint after concrete placement. The photographs in Fig. 2.33 show a typical waterstop installation using a swelling material that is adhered to the substrate with sealant.

FIGURE 2.33 Installation of swell-type waterstop.