DE19940987A1 - Material used in the production of calcareous sandstone comprises chalk, sand, water and additives to raise the suppleness of the material in the non-hardened state - Google Patents

Abstract

Material comprises chalk, sand, water and additives to raise the suppleness of the material in the non-hardened state. An Independent claim is also included for a process for the production of calcareous sandstone comprising producing the calcareous sandstone using an extrusion/extrusion molding process, in which the material to be molded is pressed using a tool and then hardened.

Description

The present invention relates to a material for the production of Limestone includes lime, sand, water and additives and a Process for the production of sand-lime brick.  

It has been known for more than a hundred years from a mixture of lime, Sand and water to produce so-called sand-lime bricks have proven and prevailed, particularly in building houses. This Sand-lime bricks are characterized by their high density and consequently their high heat storage capacity and their high static strength. The still formable raw material from sand, lime and water is in Stone blanks pressed and then in steam hardening kettles at one Temperature hardened from 160 ° C to 220 ° C under saturated steam pressure. there brings the hot steam atmosphere chemical processes within the Lime sandstone in progress, in which the sand bodies are firmly together interlock.

The production of the sand-lime bricks in the pressing process has the consequence that in economically just simple geometric shapes are realizable. For example, cuboid bricks, optionally with one or two through holes made of lime sandstone. Other geometric shapes, for example L-shaped slab curbs for slab formwork, U-shaped Scarf stones or so-called hollow hole bricks are used in the manufacture of Well-known pressing processes so expensive that there is no sales for this market finds.

When building houses, in addition to the known sand-lime bricks often used bricks made of clay. These bricks are made from a raw material by extrusion, the still deformable raw material with high pressure through a shaping Tool is pressed and the raw material so shaped is then fired for curing. The ones so burned Clay bricks can take and become almost any shape currently used, for example, as hollow hole bricks in house construction, because these hollow hole bricks are high strength and comparatively good  Have thermal insulation values at an acceptable price.

Although such extrusion processes for clay tiles and Sand-lime bricks as such have been known for several decades, So far it has not been possible to extrude stones made of lime sand manufacturing process.

Proceeding from this, the present invention is based on the object to create a sand-lime brick that takes almost any shape can and is still inexpensive to manufacture.

The present invention is based on the knowledge that the Extrusion (synonym: extrusion) of the not yet hardened Sand-lime brick material fails because the sand-lime brick material is too brittle is why the material that is already formed and emerging from the mold always receives cracks again or even tears off completely.

As a technical solution to this problem, the invention proposes to supplement the known sand-lime brick with an additive which the smoothness of the lime sand material in the uncured state increased, the additive in particular oil, soft soap, cellulose Derivatives, especially methyl cellulose, clay, preferably bentonite clay or a combination of at least some of the aforementioned materials having.

A material designed according to this technical teaching has the advantage that by adding one or more of the above means the otherwise brittle combination of lime and sand very much becomes smoother. Because of this improved suppleness the molded lime sandstone emerging from the extrusion mold Shape without cracks. Even after hardening remains  the sand-lime brick thus created is dimensionally stable and without cracks.

Further advantages of the material according to the invention and the invention according to the method result from those described below Embodiments. Likewise, the above and the According to the invention, features which are further elaborated in each case individually or can be used in any combination. The The mentioned embodiments are not to be considered as a final list understand, but rather have exemplary character.

The lime sandstone is usually made from a mixture of lime and Sand (in a ratio of 1:12) was formed, with this mixture so much water is supplied that a non-flowing but still deformable Raw mass is created. According to the invention, this raw mass is now either a vegetable oil, or an animal oil (fat), or soft soap, or Methyl cellulose, or clay added. It has been found that a relatively small amount of less than 1% by weight is sufficient to the smoothness required for the extrusion to lend. Tests have shown that the content of oil, methyl cellulose or clay up to 5% by weight and that of soft soap up to 10% % By weight can be increased without losing the material Extrusion capability loses. It goes without saying that everyone Intermediate values are suitable.

When extruding a material prepared in this way, it is also used Overpressure pressed by an appropriate molding tool, so that on an endless blank of the other side of the mold Lime sandstone with the appropriate shape emerges. This blank is usually transported on a treadmill and then in cured in a known manner.  

Below is an example of a particularly suitable material composition listed. Here, the lime sandstone has 85% sand, 10% lime, 3% soft soap, 1% vegetable oil and 1% methyl Cellulose. So much water is then added to this mixture until one non-flowing yet deformable raw material is created. Alternatively For this purpose, the methyl cellulose can also be replaced by bentonite clay.

By adding dissolving and / or blast furnace slag and / or Lime sandstone becomes even firmer in slag sand. At the same time, through Adding release and / or blast furnace slag a good freeze and Resistance to de-icing salt of the sand-lime brick achieved. By adding Water repellents, in particular zinc stearate Lime sandstone particularly moisture and weather resistant. By the The addition of gas concrete granulate makes the sand-lime brick very easy to process and there is a weight reduction while at the same time the Lime sandstone insulation values can be increased.

An increase in the compressive strength of the sand-lime brick is achieved achieved by quartz sand, silica or diatomaceous earth. By adding Fiber material, especially glass fibers, will increase the strength of the Lime sandstone further increased.

Claims (7)

1. Material for the production of sand-lime brick comprising lime, sand, water and additives, characterized by an additive to increase the suppleness of the material in the uncured state. 2. Material according to claim 1, characterized, that the additive oil, soft soap, cellulose derivatives, in particular Methyl cellulose, clay, preferably bentonite clay or a Combination of at least some of the aforementioned materials having. 3. Material according to claim 2, characterized by
a share of 60% to 95% sand;
a share of 3% to 15% lime;
from 1% to 25% water;
from 0.25% to 5% oil;
a proportion of 0.25% to 5% methyl cellulose or clay, in particular bentonite clay;
a proportion of 0.5% to 10% soft soap. 4. Material according to one of claims 2 to 3, characterized, that the material continues to be loose or blast furnace slag, slag sand, Gas concrete granulate, quartz sand, silica, kieselguhr, fiber material, Water repellents, especially zinc stearate or a combination nation has at least some of the aforementioned materials.   5. Material according to one of claims 2 to 4, characterized, that the oil is vegetable or animal oil. 6. Process for the production of sand-lime brick, characterized, that the sand-lime brick is produced by extrusion / extrusion, in particular, that the still formable material with overpressure a tool is pressed and then hardened. 7. The method according to claim 6, characterized, that the material according to at least one of claims 1 to 5 is formed.