Radius used to form wastewater tanks for energy production
Sewage treatment plant, Simple and reliable contract completion
The growing environmental awareness of the world’s population is leading to the increased use of alternative energies. Wide-ranging technologies are now available to tap into renewables such as solar power, thermal energy or biomethane.
A construction project in the French town of Cagnes-sur-Mer sets out to use a combination of these various resources. The scheme is for a sewage treatment plant incorporating new technologies to exploit the resulting sludge such that more energy is generated than consumed. The required tanks were built using MEVA systems, which similarly impressed by their smart combination of technologies. „The digesters are engineering structures built into the ground so, in preparing for their construction, we looked into a number of possible formwork solutions,“ explained Luis Soares, Chief Operating Officer at ABB Construction. „During the on-site operations, we greatly appreciated the reliability and technical features of the MEVA system, and the end product is a structure meeting very high quality standards.“
Single-sided circular formwork
Contractor ABB Construction‘s first step was to look for a circular formwork system suitable for single-sided pours against existing structures. MEVA‘s Radius system for curved walls comprises ready-to-use formwork panels that accommodate radii upwards of 2.5 m and allow exact adjustment. The use of separate external and internal units allowed the single-sided procedure to be adopted for the project in Cagnes-sur-Mer.
The brief called for the construction of two circular containers, each with a radius of 8.20 m. The integrated spindles of the Radius circular formwork were used to set the required radii. By providing for continuous adjustment, the system guarantees inch-perfect precision.
Shipshape and watertight
Prior to the start of formwork erection, the container perimeter was first lined with a waterproof membrane. The properly adjusted formwork panels were then put in place. Use of the familiar MEVA assembly lock vouched for straightforward, flush and structurally continuous panel connections.
Support frame ideal in tight spaces
With MEVA‘s STB 450 support frame, the building professionals from ABB Construction benefited from an ideal solution for casting against existing structures. The smart system for single-sided pours is only 2.45 m deep, fits onto any truck and took up relatively little space even inside the 51.5 m² tanks. The space-efficient assembly thus left the site operatives with ample room to move around.
Simple and reliable contract completion
To speed up the works, the contractor exploited the maximum capacity of the circular formwork system by casting the tanks to the full height of 6.5 m. The installed load cells indicated a pressure of approx. 60 kN/m², equal to Radius‘s standard fresh concrete load capacity. This pressure was reliably transmitted from formwork to foundation by the STB 450‘s robust, heavy-duty steel frame. In this way, each container was simply and reliably completed in three cycles. The containers were then vertically extended using two-sided formwork to a total height of 13 m.