100 m of flood protection erected in only two days

Climatic changes ensure that rivers and streams will almost regularly overflow their banks and destroy the possessions of many residents. Many still remember the images of large floods in central Europe in 2002 and 2013. Following these disastrous floods, many places were aware that flood protection must be improved from the ground up. But how do you reliably protect people and nature from recurring flood events?

Levees are simple flood protection installations and are often implemented, especially in rural areas. However, their planning and construction are frequently protracted. Levees also require a lot of space and must be regularly refurbished.

For this reason, massive, reinforced-concrete, flood protection walls are used with increasing frequency, whether as an extension or even a replacement for levees. These protective installations have a significantly smaller footprint than levees and are built much faster. Maintenance expense is reduced to a minimum. Flood protection walls of this kind can also be delivered as precast concrete units and quickly assembled at the destination. The benefits of precast construction are obvious. Prefabrication independent of the weather, quick assembly and visual design possibilities all speak for a flood protection wall made from prefabricated concrete components.

Patented flood protection system

But how can the precast units be quickly and reliably connected to each other and the joints sealed? The patented flood protection system from B.T. innovation GmbH consists of a dry connection method for precast concrete components; the BT-Spannschloss (turnbuckle) and the RubberElast compressive tape seal.

RubberElast is delivered to the construction site in easy-to-handle rolls and simply stuck to the component being sealed. Due to the material’s properties, light pressure is sufficient for the sealing tape to adhere without primer or other preparation of the precast concrete component. After the protective strip is removed, the adjacent component is placed, connected and aligned with the aid of the BT-Spannschloss, greatly compressing the sealing tape. The resulting component joint is thus permanently sealed against unintended water penetration.

The BT-Spannschloss (turnbuckle) is a connector for precast concrete components with technical approval from the Deutsches Institut für Bautechnik. It is available in three sizes – M12, M16 and M20 – and each is made from two materials; galvanized malleable cast iron and high-quality stainless steel.Joint grouting is not required with a BT-Spannschloss connection. This allows the structure to be loaded immediately after making the screw connection. The installation can also take place without problems during low temperatures or precipitation. The RubberElast sealing tape can be installed in unfavorable weather conditions as low as -10°C. It offers reliable protection up to a 5 m water column.

Up to 50 m of flood protection wall can be erected in a day with this convenient flood protection system.

Numerous reference projects

Numerous reference projects proved that this system functions perfectly.

In 2012, approx. 1,500 m of flood protection wall was built to protect an industrial area in the Brandenburg town of Wittenberge. The wait for a practical test was short, because the level of the adjacent tributaries of the Elbe River rose again rapidly in the following year. The flood protection wall fulfilled its purpose and, as expected, the flood protection system remained intact.

In 2014, the beloved tourist destination of Heiligenhafen, a beach resort in Schleswig-Holstein, decided upon a flood protection wall of precast concrete components with connector and sealing technology from B.T. innovation to protect an emerging high-end vacation resort. To meet the visual requirements and adapt the flood protection wall to the overall image of the idyllic area, color pigments were mixed into the concrete, permanently coloring it. The result has been visible there since then – a visually appealing and reliable flood protection wall.

One year later and only a few meters away – also at the Heiligenhafen marina – a similar solution was selected. This protection wall was also connected with the BT-Spannschloss and sealed with RubberElast. Coloring of the concrete was not necessary here, because the concrete elements fit perfectly into the overall scene, thanks to their high-quality production. The structure with the innovative flood protection system was built in minimal time, so even the rather unsightly construction machinery could be quickly removed from the idyll.

The flood protection area of a small community in Sachsen-Anhalt was also retrofitted in 2017 after the river flowing through it overflowed its banks several times in recent years and caused chaos. Building levees in harmony with nature was preferable, but that was not straightforward at every location. The newly built levees were therefore supplemented with precast concrete flood protection walls. A total of almost 1,000 m was required. The client – the state of Sachsen-Anhalt – and community residents are very satisfied with the result. The tight schedule and budget were met without difficulty due to use of the flood protection system and a reliable flood protection installation was created.

Flood protection with colored concrete

Not everyone knows that concrete does not always have to be gray. Precast concrete components can be greatly upgraded visually with inorganic color pigments. Manufacturing is uncomplicated and does not necessarily involve higher costs. Since flood protection walls must also increasingly be built in inner cities, this enhancement method offers itself. B.T. innovation presented its permanent flood protection system at the Aqua Alta flood protection trade fair, which took place in Essen in January of this year.

The Lanxess company, was also represented on the stand as a cooperation partner with its Bayferrox brand iron oxide pigments. This allowed interested customers to obtain advice about both technical implementation and visual upgrading. Thus, the systems can be individually adapted to urban architectural circumstances and no longer need to be perceived as a disruptive element. In this way, effective protection becomes an architecturally appealing overall concept.