Tunnels, Waterproofing, and Closing the Gaps

Concrete isn't the only part of the project that needs waterproofing

It’s an interesting thing – it’s comparatively simple to waterproof concrete itself.

What’s not so straightforward is waterproofing air.

The air between

Specifically, let’s talk about air-space between sections of concrete, otherwise known as construction joints or expansion joints.

Hey, let’s get even more specific, and talk about tunnels. In modern tunnel construction, the shafts are lined with interlocking segments of precast concrete. So how do we waterproof the air between those segments?

We all know about gaskets

You’re reading this and thinking to yourself, have they never heard of gaskets? Of course we have. Flexible-form waterstop gaskets are the obvious response. But what type, exactly?

The most common form of adhered gaskets in use are made of bentonite clay. This substance is definitely waterproof once construction is complete and the gap is minimized. However, it is not resistant to weather, if exposed to the elements for lengthy periods of time.

Weather-resistant gaskets?

Let us introduce you to CONQOR 47B and 87B delayed swell waterstop gaskets. These react to the presence of moisture and swell slowly, without delamination, and remain in place for the duration of the construction phase. And for their long-term service life, of course.

The two types have different swell rates, depending on the likely degree of exposure to the elements.

So where do tunnels come in to the story?

These gaskets are in current use in three major rail tunnel infrastructure projects in Australasia. They are used not only between the precast tunnel wall segments, but also at the interfaces between tunnel and exits, and in the station and platform areas.

You can depend on CONQOR 47B and CONQOR 87B delayed swell waterstop gaskets to go the distance.

Close the gap with CONQOR waterstops.

Waterproofing a structure? How about the air between? Get in touch to discuss design and installation options.

Download information on CONQOR Waterstops here.

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