TT ceiling formwork delivered to Elementbau Osthessen

For more than 50 years, Elementbau Osthessen has been one of the most high-performing companies in the precast concrete industry in Germany. In Eichenzell near Fulda and at its partner company BFE in Erfurt, a wide variety of precast reinforced concrete elements are produced. ELO Beton develops and manufactures concrete components in a wide range of shapes, colors, and functions to meet the most diverse customer requirements. The possibilities for aesthetics and design are diverse - ranging from architectural concrete to commercial and industrial construction to bridge building.

ELO Beton is known for the high quality of its products. The company utilizes state-of-the-art technologies and innovative technical equipment, enabling it to achieve very short planning, manufacturing, and delivery times for precast reinforced concrete elements. The production technology was recently updated: Beta Maschinenbau GmbH & Co. KG, Heringen, supplied a formwork system for the production of TT floor elements and T-beams in a parallel configuration with infinitely variable web height adjustment and a fixed formwork core.

Scope of delivery

The design was implemented as an internal prestressing system to absorb the prestressing forces via special bracing of the overall structure, with the following parameters:

Length 45.0 m

Segmentation: 1 x 45.0 m per side

Construction width approx. 5,000 mm

Total width when extended: approx. 5,100 mm

Upper chord width, effective formwork dimension of TT element 3,000 mm (+ 200 mm)

Core width, fixed: 1,000 mm

Flange width approx. 550 mm, angle adjustable

Rib production height 300 to 1,000 mm (floor formwork to be provided by the customer)

Rib width 170–250 mm, infinitely adjustable

Formwork core and side elements in sharp-edged design

Cylinder stroke, side 1: 1,000 mm

Cylinder stroke, side 2: 1,000 mm

Edge formwork to be provided by the customer

Formwork sheet thickness 8 mm

Formwork sheet quality S235.

The scope of delivery also includes mounting plates for bolting on external vibrators. The highly stable and torsion-resistant base frame, decoupled by means of Schwing metal rails, forms the basis for the modular design of the TT formwork. Heavy insert beams, designed as cantilever arms, are installed in the cross members of the base frame. These absorb the overturning forces resulting from hydrostatic influences. Connected to the insert beams are the sliding frames onto which the TT modules are welded. The sliding frames are designed to be extremely rigid and, together with high-quality speed controllers, ensure the desired synchrony in the axis-parallel feed of the side formwork. A center frame structure with an integrated T-core module is provided in the center of the formwork. Additional options include the inclination adjustment of the two outer and core walls. A thermal oil heating system is integrated into the core and the side elements.

The floor formwork, consisting of multi-layer formwork panels, is provided by the client. In addition, there is a hydraulic floor height adjustment system for placing and securing a site-supplied formwork floor. This system is mechanically adjustable. The floor height adjustment can be moved up to 700 mm in height (adjustment range approx. 700 mm); the adjustment is performed by hydraulic cylinders.

The vibration equipment, consisting of formwork with a vibrating system, was supplied by Wacker, including a frequency converter with group switching, a radio remote control, and matching distribution boxes. The compaction of the webs can be controlled separately.

Constructive Collaboration

Sebastian Hoyer, project manager at Beta, expressed his great satisfaction: “From the initial discussion with ELO in late January 2024, through the project award on December 16, 2024, and the order on December 20, all the way to delivery in late August 2025, the entire process proceeded very smoothly and without major issues. So a big thank you to everyone involved in the project for the smooth and constructive collaboration.”

During the discussions, the initial consideration was to apply prestressing against the formwork; ultimately, a variant with a wall to absorb the tensile forces was chosen. After the order was placed, Beta began designing the formwork. The formwork was designed and manufactured in close coordination with the customer. The foundation footplates were prepared in advance by ELO, enabling rapid assembly, and the formwork was installed in the final step.