FR2499897A1 - Plaster mouldings, esp. tiles or blocks - made from mixt. of plaster with large amt. of sand and small amt. of water, so both material and drying costs are reduced - Google Patents

Abstract

The mouldings are made by stirring very fine sand in water to obtain a suspension to which plaster is added while stirring is continued. The resulting mixt. is poured into a mould. The moulding is then removed from the mould and is dried so its moisture content is reduced to ca. 3%. A plasticiser which reduces the vol. of water required is pref. added to the water, or to the sand suspension before adding the plaster. The amt. of sand is pref. 80-100% of the wt. of plaster used; and the moulded object is pref. a tile or block 50-120 mm thick. Used e.g. as internal partition in building etc. Material costs are reduced by using a large wt. of sand; and drying energy is reduced by using a relatively small amt. of water in the mixt.

Description

 The present invention relates to a method of manufacturing a plaster object such as for example a tile.

 For many years now, the use of plaster objects such as tiles has grown considerably, particularly in the construction industry, and it has become the custom to use plaster tiles of standardized format for the realization of interior partitions in premises of extremely diversified use such as for example housing, school, commercial, hospital, etc.

 However, these plaster tiles, despite all their advantages, have a drawback from the point of view of sound insulation, and are often accused, not without reason, of 8tr at the origin of the lack of comfort in many recent buildings.

 Furthermore, it turns out that the manufacture of plaster tiles is relatively expensive, since on the one hand the manufacture of plaster requires a considerable amount of energy and on the other hand, the manufacture of the tiles itself requires a large amount of mixing water and therefore a significant expenditure of drying energy.

 The object of the present invention is to remedy these drawbacks by developing a process for manufacturing plaster objects, such as tiles of standardized dimensions corresponding to those of the tiles usually used for construction, the properties of which are 'sound insulation are significantly improved, and the manufacture of which is of a cost significantly reduced compared to tiles of the same type of the prior art.

 To this end, the process which is the subject of the invention is characterized in that very fine sand is mixed with stirring of the water so as to obtain a suspension, plaster is added to the mixture while continuing the 'stirring, the mixture obtained is poured into a mold of a given shape, then the object obtained is removed from the mold and dried until its residual humidity is reduced to a value close to 3%.

Consequently, according to the process which is the subject of the invention, the plaster serves as a hydraulic binder to the sand.
We thus obtain a denser material than the usual plaster tiles, and therefore, of course, whose sound insulation properties are significantly improved.

 In order to obtain suitable properties from the point of view of hardness and mechanical strength, the plaster is, according to another characteristic of the invention, tempered more tightly "This is obtained by adding it to water for mixing a water-reducing plasticizer apFrori The water-reducing plasticizer used is a plasticizer commonly used in construction and in particular in the manufacture of concrete, in particular products based on Melanin or lignosulfonate.

 According to another characteristic of the invention, the plasticizing agent is added to the suspension of sand in water before the addition of plaster.

According to another characteristic of the invention, the amount of sand used represents 80 to 100% by weight of the amount of plaster. In this way the dry plaster tile contains approximately
- flat: 43%
- sand: 43%
- water: 14% (constitution water + free water).

 Consequently, the process which is the subject of the invention makes it possible to achieve a significant energy saving, on the one hand, at the level of the raw material, since it requires a much smaller amount of pitre than the manufacture of conventional type tiles, and on the other hand, in terms of drying, since this process requires a much lower amount of mixing water and therefore a significantly reduced amount of drying energy.

 However, this economy is far other negligible in present times, where one seeks at all costs to reduce energy expenditure.

 The present invention also relates to an object such as a pleasing tile obtained by the implementation of the method described above.

 By this method, it is possible, in particular, to obtain plaster tiles in standardized format whose thickness may vary between 50 and 120 mm, which may be suitable for the production of interior partitions in any premises.

Claims (6)

 10) A method of manufacturing a plaster object such as for example a tile, characterized in that one mixes with stirring of batten and very fine sand so as to obtain a suspension, plaster is added to the mixture while continuing stirring, the mixture obtained is poured into a mold of determined shape and dimensions, then the object obtained is removed from the mold and dried until its residual humidity is lowered to a value close to 3 5 '.  20) Method according to claim 1, characterized in that one introduces into the mixture a water-reducing plasticizing agent.  30) Method according to claim 2, characterized in that one adds the plasticizing agent in the suspension of sand in water before the addition of plaster.  40) Method according to any one of claims 1 to 3, characterized in that the amount of sand used represents 80 to 100% by weight of the amount of pldtre.  50) An object such as a plaster tile, characterized in that it is obtained by implementing the method according to any one of claims 1 to 4.  60) plaster tile according to claim 5, characterized in that it has a thickness between 50 and 120 mm.