U-Bahn® Beton

Alleggerimento per solai monodirezionali

U-Bahn® Beton is a modular formworks in recycled plastic that was specifically designed to create one way slabs that are cast on site or semi-prefabricated.
The various modules, which overlap on the edges, make it possible to create beams of any length.
Thanks to its conic elevator feet, immersing the U-Bahn® Beton formworks in the concrete casting will obtain thick, parallel beams that are closed from the bottom and top by a flat plate made in sequence with a single casting; this results in reduced use of concrete and steel as well as considerable advantages in terms of fire risk in comparison to formworks in expanded polystyrene.

Light and stackable, it is easy to handle during positioning, functional in its use, can be exposed to bad weather and is easy to store in the yard with minimum dimensions.

Designed according to strict quality criteria, the U-Bahn® Beton permanent formwork is guaranteed to resist without concrete 150 kg concentrated on a load imprint of 8 x 8 cm, as foreseen by current regulations.
Unlike with the use of classical hollow brick blocks, the empty space left by U-Bahn® Beton can be used for the passage of cables and systems.

REFERENCES

New eco-friendly building for RIVM /CBG, new governative edifice with laboratories

Utrecht scientific park (The Netherlands)
U-Bahn® Beton

Underground parking in the city center

Brescia - Italy
U-Bahn® Beton

Underground parking for a residential building

Conegliano (TV) - Italy
U-Bahn® Beton

View all projects

ADVANTAGES

Sistemi di alleggerimento per solai monodirezionali

Reduction in time and cost related to positioning the formworks.
High precision and regularity of the width of the concrete slab ribbing.
Flexible, practical and simple creation of lengths below the standard size.
Greater yard cleanliness and improved disposal of the waste in comparison to traditional formworks (hollow blocks and EPS).
Better work performance guarantee in comparison to expanded polystyrene that, due to its crumbling into granules, tends to attach itself statically to everything, and is difficult to remove, compromising the correct filling of the concrete for the beams and in the nodes.
Possibility to trim the soffit with immediate economic advantages, avoiding expensive plastering.
Advantage of using the cavities created using U-Bahn® Beton, which run along the entire slab, as an equipment room for various types of systems.

Possibility to perform a single concrete casting for the creation of lightened slabs with the slab also in the soffit. In comparison to traditional formworks (hollow blocks and EPS), the layer making up the soffit must first be cast, then the formworks and the reinforcements are positioned, and then concrete is again cast.
Quicker execution of prefabricated slabs without the need to prepare specific safety vents in the case of a fire.
Providing the slab with greater fire resistance.
Considerable reduction in the yard of overall volumes as well as the overhead handling of traditional formworks (hollow blocks and EPS) thanks to its characteristics of stackability, modularity, lightness and manoeuvrability.
Better seismic behaviour; the presence of a dual reinforced concrete layer, which makes it possible to more solidly connect the vertical structures of a building in comparison to a traditional slab.

APPLICATIONS

U-Bahn® Beton is the ideal solution for creating lightened one way slabs for all types of structures: residential, commercial, executive, industrial buildings as well as public structures (schools, hospitals, etc).

U-Bahn® Beton is fundamentally used in all applications that require one way beams and slabs as well as a reduced use of concrete and reduced weight. With U-Bahn® Beton slabs with a greater thickness can be created with less concrete.

A particular type of use of U-Bahn® Beton is for constructions carried out using the ‘top-down’ technique (by compartments or layers) where instead of working from the bottom upward, work is performed from the top downward; first the slab is created and then the excavation is made.
Underground parking buildings in historical city centres are often created using this technique due to the obvious constraints related to the presence of numerous buildings as well as the need to quickly restore traffic flows.
For projects that use this technique, it is of strategic importance to supply the yard with light-weight and non-bulky material.

TECHNICAL DATA

UBAHN^® BETON		H 13 cm	H 16 cm	H 20 cm	H 24 cm
Useful size	cm	120 x 40	120 x 40	120 x 40	120 x 40
Height	cm	13	16	20	24
Feet height	cm	0 – 4 – 5 – 6 – 7	0 – 4 – 5 – 6 – 7	0 – 4 – 5 – 6 – 7	0 – 4 – 5 – 6 – 7
Weight per piece	kg	2,2	2,6	3,0	3,8
Piece volume	m³	0,055	0,068	0,086	0,102
Pallet dimensions	cm	120 x 120 x 240	120 x 120 x 245	120 x 120 x 250	120 x 120 x 255
Pieces per pallet	pcs/PAL	270	270	270	270
Pallet weight	kg/PAL	604	712	820	1.036

INSTALLATION

1. The entire surface of the slab to be cast on site is shuttered with wood deck (or similar systems), then the welded reinforcement irons and mesh are positioned according to the design and the spacing lattice for the upper reinforcement is arranged.

2. The U-Bahn® Beton formworks are positioned with the desired centre distance that will determine the width of the beams. Thanks to the conic elevator foot, the U-Bahn® Beton formworks will be lifted from the surface, making it possible for the lower slab to be formed.
The systems will be arranged in the internal cavities of the formworks.

3. The positioning is completed by closing the open final ends of the U-Bahn Beton® formwork with a lateral closing plug above which the reinforcements, welded mesh as well as the instruments for cutting and punching are positioned according to the design.

4. The concrete casting must be performed in two phases to prevent the floatation of the formworks: an initial layer will be cast to form a thickness equal to the height of the elevator foot. Casting will continue for this first portion of the slab until the concrete starts to set and become less fluid.

5 . Once suitably set, the casting can be restarted from the starting point, completely burying the U-Bahn® Beton. The casting is then levelled and smoothed in a traditional manner.

6. Once the structure has hardened, the formwork can be removed. The surface is smooth in correspondence of the soffit.

PHOTO GALLERY

F.A.Q.

U-Bahn Beton^® or lightening in polystyrene?

Even if polystyrene is widely used in the construction industry due to its low cost and workability, it has many disadvantages that are being addressed by the technical-scientific community.

With reference to lightened slabs, the Italian Ministerial Decree of 16.02.2007 to enclosure D.5.1 establishes that: “In the case of polystyrene formworks, or formworks in similar materials, there must be appropriate vents for the overpressures”. Even prior to this, the UNI 9502 standard – article 7.2.2 – established that: “In the case of elements incorporating materials that when subject to high temperatures turn to gas, there must be appropriate vents facing the side exposed to fire to ensure that the bearing capacity is not compromised by explosions”.

Therefore, using polystyrene slabs cast on site requires the extra expense of fitting vents in the cavity to counteract the excessive pressure of gas that is sublimated by the formwork. However, in the event of a fire there would still be the problem of toxic gas escaping into the environment (styrene).

As U-Bahn Beton^® is made of polypropylene, it is not toxic even if burnt. Moreover, the slab will not explode due to the escaping of over pressurised gas from the feet (4 every 20 cm of the formwork) that act as safety valves.

Other advantages of U-Bahn Beton^® compared to EPS are the dimensions, handling (just think of transferring it overhead on the slabs being built) and outdoor storage. Polystyrene is, in fact, bulky and cannot be stacked; it is particularly fragile on its edges and corners that crumble leaving those annoying balls that, statically charged, stick to everything (especially to the reinforcements) and are very hard to get rid of.