DE4308655C2 - Silicate concrete in the form of a preformed component - Google Patents

Description

The invention is directed to a silicate concrete in the form of a preform th component, in particular in the form of a sand-lime brick, made of a mixture of quartz-containing sand, lime, aggregates and what by press molding and subsequent autoclave treatment.

Silicate concrete is used in the form of sand-lime bricks for masonry construction, dense silicate concrete for prefabricated parts, aerated concrete for bricks and finished parts and similar applications.

In the manufacture of silicate concrete, aggregates and binders react forming a lime-sand binder. The chemical reaction is running so that the sand used in the autoclave in a basic environment, the is caused by the lime used and the mixing water Saturated steam conditions dissolve on the surface and with the cal zion ions of the solution with formation of calcium silicate hydrates responds. The newly formed binder minerals grow into the rough ability of the grains of sand and, above all, grow together to form egg dense, but fine-pored structure that gives the products the required Gives strength.

This type of concrete production is therefore very economical for economic reasons advantageous because no gravel has to be used as an additive yes, it is available in ever smaller quantities, and because only about  8 to 10% lime must be added as the primary binder compared to about 25% cement in normal concrete.

The basic mixture described above is hardened before the autoclave tion pressed to moldings, z. B. to bricks as a finished product then referred to as sand-lime bricks. In addition, you can any other pre-formed building parts can be produced.

The quality of silicate concrete also depends largely on the quality of the deposited quartz sand. Quartz sand has a relatively narrow grain size tied up and has little fine grain.

For a good pressure and abrasion resistance of the finished product is a even grain size band with enough fine grain to be removed fill the voids between the coarse grain and beyond one The most advantageous reactive phase of the mixture for hydrate formation required for the hydrothermal curing process.

Accordingly, they are conventionally added to the previous ones Based on the basic materials mentioned, additives and fillers are also used sets that partially replace the natural quartz-containing sands. As such fillers are, for example, from DD-OS 25 70 63 kaolinab sande, from the magazine "Baustoffindustrie" 1982, H2, page 48, glass break, from DE-OS 37 33 564 iron silicate slag, from DE-OS 37 01 856 cupola slag and from DE-OS 37 26 256 loess and high furnace slag known. When choosing the fillers or aggregates went So far, one has generally assumed that aluminum-rich minerals are disruptive would work.  

From GB 1,091,766 the production of a sand-lime brick using very fine, pure silicate flour is known. The addition of granite or basalt is also mentioned there, but as a coarse component. In QUINCKE, J.-E. "Production of sand-lime bricks of the density class 2.0 and larger" in DE research report, Research Association Lime-Sand eV of the Federal Association of Sand-Lime Stone Industry Hanover, No. 55, March 1982, the production of sand-lime stones of the density class 2.0 kg / dm ³ and described as greater than desirable. For this purpose, it is taught to replace the lighter quartz sand in the medium and coarse grain class 0.4 to 3.0 mm with a specifically heavier basalt or diabase grain.

The invention has for its object silicate concrete, in particular Sand-lime bricks to improve so that the pressure and abrasion resistance cost-effective producibility can be increased. In addition, it should be possible as fillers or additives, in particular such materials s to be used as waste materials in other processes fall, so that not only an inexpensive procurement of these substances is possible, but also one by using them Disposal is accomplished.

This object is achieved according to the invention by adding up to 25% by weight diabase in the form of crusher or cyclone dusts. This jam always fall in standardized, constant grain sizes (0.01 to 0.09 mm).

Surprisingly, it has been shown that such an addition also closing intensive mix before manufacturing the blanks the quality  the end products, especially of sand-lime bricks, are significantly improved, by increasing the pressure and abrasion resistance and the duration of the hy drothermal hardening can be reduced by up to 30%.

The diabase used according to the invention also acts as a filler and as a reactive phase. This explains the improvement in strength as well as shortening the duration of hydrothermal curing.

Through the participation of the very fine-grained diabase according to the invention The amount of 25% by weight must not be added to the hydrothermal reactions exceed, because additional shares to a too large Lö concentration that shifts the chemical equilibrium so that the strength of the finished product is reduced again.

Diabase is a waste product in the form of crusher and cyclone dusts and can be an economist through the inventive design socially useful use.

The amount to be added in individual cases also depends on the grain size of the filler or aggregate and the grain composition of the sand or the sand-aggregate mixture. Usually lies the proportion of the filler or aggregate according to the invention is demented speaking at about 10 to 15 wt .-%.

The use of diabase according to the invention for the production of lime sand stones are not exhausted when used as fillers, but he also extends to use as an aggregate.  

In summary, it can be said that the use of Diabase in dust form a high compared to conventional sand-lime bricks Edge and pressure resistance, exceptional frost protection, one Shortening the reaction time and saving limescale due to limescale tution by the basic diabase with simultaneous disposal of a Waste material are realizable.

The invention is described below on the basis of a preferred embodiment for example compared to a manufactured according to the prior art Product explained in the form of a sand-lime brick:

State of the art

A mixture of 90% quartz sand and 10% lime is used as the starting material and 6% water used.

The sand has a grain size range of 0.1 to 7.0 mm and ad ₅₀ of 0.7 mm. The mixture is pressed at a pressure of 88.29 bar to raw and cured in an autoclave at 15 bar and 200 ° C under a saturated steam atmosphere.

The hardening time of the blanks is 5 hours including 1 hour Heating time.  

Embodiment according to the invention

It is a mixture of 80% sand, 10% lime and 10% diabase in the form of crushing dusts with a grain size of 0.01 to 0.06 mm and 6% water used.

The procedure is the same as above in connection with described the prior art. Only the hardening time of the raw including the one-hour heating-up time was only 4 hours.

comparison

The visual assessment of the edge fortress shows that the according to the state Technically produced stones after a transport of approx. 170 km and multiple rearrangements show severe edge damage, while the stones produced according to the invention under the same conditions little abrasion and have high edge sharpness. The surface is also much smoother.

Claims (1)

Silicate concrete in the form of a preformed component, in particular lime sandstone, made from a mixture of quartz-containing sand, lime, aggregates and water by compression molding and subsequent autoclave treatment, characterized by the addition of up to 25% by weight of diabase in the form of crushing or cyclone dusts .