EP0610634B1 - Process of construction of floating floors - Google Patents

Description

With modern construction techniques (reduction of floor thicknesses, increased spans, development curtain walls, generalization of air equipment conditioning, ...) the problems of transmission of vibrations developed.

When these vibration and acoustic nuisances are judged unacceptable for the use of a room, a machine or a equipment, it is possible to globally separate the affected floors. This principle also makes it possible to install hectic machines on suspended slabs, thereby filtering the vibration at the source.

The present invention relates to a method for implementing works of such floating floors. These consist of a concrete slab resting on helical spring boxes, dimensioned according to static loads, overloads and excitations to filter.

The prior art to the present invention for the implementation floating slabs work consists of pouring concrete on plates or synthetic elements with characteristics limited and poorly known elastic bands, the peripheral seal of the room being made of the same materials. This technique does not allow not obtain sufficient installation natural frequencies low to guarantee good filtering. In addition, when setting up work of these elastic elements, "rigid bridges" are created between primary floor and floating slab. These hard points favor the solidary transmission.

Document GB-A-466044 of 28/11/35 describes such a patented process implementation of floors on resilient supports that can be visited and adjustable limited to the acoustic range "according to the preamble of claim 1. The performance of supports in natural or synthetic rubber, are nevertheless limited to acoustic filtering and cannot affect the solidary transmission of vibrations.

The lack of flexibility in resilient supports also leads to significant constraints in their periphery when lifting the floor until possible cracking of the concrete.

• Les caractéristiques du ressort hélicoïdal sont en effet connues et stables dans le temps.
• Le plancher flottant de la présente invention est totalement désolidarisé de la dalle primaire.

The present method offers the advantage of guaranteeing practical installation natural frequencies in accordance with the theoretical frequencies determined by the calculation:

• The characteristics of the coil spring are in fact known and stable over time.
• The floating floor of the present invention is completely separated from the primary slab.

The coil spring boxes can be visited and adjusted and therefore allow the characteristics of the suspension to be varied depending on any changes in expenses.

The floating floor of the present invention may be intended for ensure either "active" filtering (for example technical room for air conditioning) or "passive" filtering (for example protection against noise and vibration nuisance from networks metropolitan, rail and road or with regard to equipment various techniques).

The present invention describes a method which makes it possible, by occasional presses, low frequency settings and therefore very high filtering performance, while retaining for the civil engineering company an ease of implementation.

• La figure 1 représente la boíte à ressort (vide) lors de la coulée du béton.
• La figure 2 illustre la mise en place du ressort précontraint après sèchage de la dalle.
• La figure 3 montre l'opération de levage et de réglage du plancher.

A non-uniform distribution of the elastic supports makes it possible to easily take up point loads (machines) or peripheral loads (partitions) without increasing the stresses in the floating floor. The 3 attached figures describe the present invention:

• Figure 1 shows the spring box (empty) when pouring concrete.
• Figure 2 illustrates the installation of the pre-stressed spring after drying of the slab.
• Figure 3 shows the floor lifting and adjusting operation.

The method of the present invention uses spring boxes helical (1) integrated into the floor (2) during concrete pouring, the primary slab (3) serving as formwork. The floor is covered with two polyethylene films before casting to avoid any spurious bond.

Anchors (4) provided on the spring boxes allow to secure these with the concrete and its reinforcement. A joint temporary polystyrene around the premises will be destroyed before lifting of the work.

The lifting of a thin reinforced concrete structure by occasional supports is a delicate operation. Concentration of vertical efforts can cause significant constraints in the periphery of supports.

The release of the pre-stressed spring (5) allows the progressive lifting of the floor after drying. The present invention is therefore characterized in that the lifting forces by punctual support are never greater than the prestressing force of the spring with contiguous turns. The screw lifting systems, described in particular in document GB-A-466044, do not guarantee the same progressiveness.

Spring boxes, visitable and removable for upgrading loads carried, allow, by adjusting the plate seat, (6) using the screw (7) to level the structure. The spring and the interior of the spring boxes are protected against corrosion in order to guarantee a good behavior of the system in the time.

The spring box is sealed with a cover (8) in the plane of the ground.

Claims (6)

1. Method of construction of a reinforced concrete floating floor supported by the structural floor (3) in which empty spring units are installed before pouring concrete (2); in these units are intalled prestressed helicoidal spring (5) after drying of the floating slab.Then the springs are released allowing the progressive lifting of the floating slab from the structural floor, while doing elastic points with natural vertical low frequency filtering vibrations.
2. Method as set forth in claim 1 : the units are accessible after putting the floating floor into service, by opening a visiting cap (8) and each support is removable and adjustable in height by screw (7).
3. Method as set forth in claim 2 : inspection, removal, and adjustment of the spring units allows the adjustment in height and frequency, in case of weight change and dynamic excitation change in the structure.
4. Method as set forth in any of the above claims : fixings (4) on the spring units allow to join these to the reinforced concrete.
5. Method as set forth in any of the above claims : the helicoidal springs and the inside of the units are corrosion protected against.
6. Method as set forth in any of the above claims : the helicoidal spring units are closed by a cap (8) on the slab level.

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