Sealing expert prevents 'flooding'

Especially in the winter with potential danger of freezing up. To prevent leaks and potential road closures on the Blankenburg connection, construction consortium BAAK engaged sealant expert Vilton.

Vilton is initially involved in the groundwater sealing of the Holland Tunnel. Further construction sections will follow later. The tunnel is being built in depth as a "box structure" with walls and a floor in concrete. "To prevent cracking in the concrete, a dilatation joint is included every x-number of meters," explains Addy Hardenbol, technical specialist for concrete & infra at Vilton. "Such a dilatation joint forms an open connection with the groundwater. We then supply a rubber joint tape to seal that connection while allowing the concrete floor and wall elements to function."

Inside and outside joint tape

Vilton is supplying a large number of meters of expansion joint tape for the Holland Tunnel. Hardenbol: "This is what is known as an internal jointing strip with external steel plates of the FMS type, suitable for use in tunnel construction. The joint tape has an injection hose that provides an active seal on two sides. In addition, we also supply external joint tape type AM 350 to BAAK for higher sections. These joint bands prevent sand or soil from settling in the dilatation." The joint bands are supplied as a system. Vilton itself takes care of vulcanization on site. "The welding of the joint tape is done by our own certified employees. This is to guarantee quality. The same applies to the special junctions, such as shaped pieces or T-junctions. These are completely prefabricated at our factory and delivered ready-to-use to BAAK."

Lost expansion joint formwork system

Another system that Vilton is making good use of in the infrastructure industry is the lost expansion joint formwork system type DHI with FMS joint tape. "It is not yet in use at the Blankenburg connection, but could possibly be of added value at a later stage," says Hardenbol. "Forming one floor leg with an expansion joint tape in it takes a lot of time. Shuttering has to be done, the FMS dilatation joint tape has to be set, then the concrete is poured and then it has to be stripped again. All in all, very time-consuming. The advantage of using our lost formwork system DHI is that two or more floor slabs can be formworked, reinforced and poured at the same time, without the need for stripping the formwork. This saves an enormous amount of time and is less labor intensive. The concept has already been successfully applied to several infrastructure projects."