DE3816686C2 - Thermally insulating wall component and method for its production - Google Patents

Description

The invention relates to a heat-insulating wall component. Under the wall Components are building blocks in various formats, plate-shaped Wall segments or even industrially prefabricated interior and exterior of the building walls to understand. The subject of the invention was particularly in the Hin look at the production of plate-shaped wall segments in common wall works thicknesses of 5-37.5 cm. The length and height dimensions these wall segments are a multiple of the usual bricks. you will be especially with the so-called "casament" (limestone-sandstone element) construction used, with all building exterior and interior walls in the planning stage in Disassembled segments, industrially prefabricated in the desired dimensions then transported to the construction site and merged there according to plan to the building be set. Compared to the conventional stone-to-stone walls, this results due to the casament construction a considerably shorter construction time.

Traditionally, the casament wall segments are industrially prefabricated from individual accordingly assembled and glued sand-lime bricks. For a better understanding of the invention, the usual manufacturing process for sand-lime bricks will first be briefly outlined here:
The raw materials - lime and quartz sand - are dosed by weight or volume, mixed intensively with each other and fed into the reaction tank via a conveyor system, where the quicklime is extinguished to form hydrated lime. The material to be mixed is then brought to press moisture in the post-mixer. The stone blanks are formed from the press-moist mix with fully automatic presses. Then the blanks are hardened in so-called hardening kettles at temperatures of 160-220 ° C under a saturated steam pressure of about 16 bar. The hardening process takes about 4-8 hours. After hardening and cooling, the sand-lime bricks are ready for use. Such a method or a sand-lime brick produced with it are described in DE 28 37 854.

A particular disadvantage of sand-lime bricks is their low thermal insulation tion, which of course also applies to the wall components made from it. Around to achieve an improvement here, the binder mixture from the hy drothermal curing binder (quicklime or hydrated lime) and the fei quartz sand or flour is a heat-insulating, granular lightweight aggregate be added. This is that of the binder mixture by hydrother male curing formed silicate-bound matrix.

In the production of thermal insulation based on the sand-lime brick production menden wall components of the type mentioned problems occur in the Hardening in the hardening vessel. As a result, the heat-insulating lightweight aggregate fabric, the wall component is so poorly heat-conducting that the hardening required heat only very slowly up to the core of the wall components penetrates. The heat that is advantageous in house construction for energy reasons Insulation therefore does exactly the same thing in the manufacture of wall components opposite. To achieve an even hardening would be drastic increased residence time of the wall components in the hardening boiler is necessary, which is a significantly lower capacity of the production plant with increased energy consumption need brings with it. This is not acceptable for business reasons.

Based on this, the object of the invention is to provide thermal insulation of the wall component of the type mentioned so that the übli  che residence time in the hardening kettle not exceeded and thus the ge mentioned disadvantages can be avoided.

The basic solution to this problem is specified in claim 1. Accordingly, the wall component, the base of which has a binder mixture of a hydrothermally curing binder and fine Contains quartz sand or quartz powder, one by a grainy light weight aggregate with a grain size of 4-16 mm Structure on. Specifically, this means that the lightweight aggregate is practically free of fine grits. The heaped structure of the Component structure means that - even after compression - in the The basic component forming the wall component is interconnected Air channels - so-called air gussets - are formed, which also with the component environment. The outward characteristic of such heaped structure is the air permeability of the element. It owns hence a very low vapor diffusion resistance.

The hydrothermal steam treatment in the hardening kettle now gets enough steam immediately as a result of the high partial vapor pressure gradient across the air ducts and directly into the interior of the wall components and heated them on their total volume evenly. This also applies to thick-walled components. The known residence time in the hardness known from sand-lime brick production This is also sufficient for the wall components according to the invention constant curing.

The addition of the heat-insulating light aggregate results especially in the production of large-scale, pore-shaped wall elements ment further problems. In contrast to the actual sand-lime brick production where the basic mass is due to its great homogeneity after compression molding the blanks have such a high inherent stability that they are stacked one on top of the other  pelt can be introduced into the hardening kettle and there under influence of the saturated steam, the heat-insulating wall elements are dimensionally stable elements are less inherently stable due to their pore structure. In particular the binder matrix due to the influence of saturated steam in the hardening vessel moist and thus softened. Based on this low inherent stability, it would be actually necessary that each wall component stabilize in one the molding box - which could then also be stacked on top of one another - or retracted individually and flat on a trolley into the hardening tank becomes. Both options are prohibited for business reasons. With the former, the extremely cost-intensive acquisition of a large number of Shaped boxes are necessary, with the second, the use of the hardening kettle is not worthwhile bar low.

For optimal utilization of the capacity of the hardening kettles, in particular plate-shaped wall segments standing upright on one of their narrow sides a usual trolley for the production of sand-lime bricks with a short distance can be arranged to each other. However, this requires a certain egg gene stability and moisture resistance of the freshly pressed wall segments so that they Remain true to shape under the influence of saturated steam in the hardening kettle. this will achieved according to claim 2 in that the binder mixture a hydraulic cal binder, such as cement, which does not yet hy Drothermally hardened lime component of the binder matrix against the stabilized by the influence of steam. The cement works through its kri stall growth a consolidation of the structure of the building element structure. Since this solidification is also mistaken by the influence of water vapor remains versible, those placed in the hardening kettle, on one of their narrow side components, the process of hydrothermal hardening is safe survive.

With regard to the most rational manufacturing process possible - what u. a. one possible  Fastest possible production and the lowest possible number of manipulations of the object of manufacture means - is to be demanded that in addition to the fast Hardening, on the one hand, the pressing process itself can take place quite quickly and on the other hand the element blanks already in the required retracted position in read out the hardening vessel - namely standing on its narrow side - the molding press can sen. This in turn means that the element blanks shortly after Compression presses already have such high inherent stability that they are essentially can carry their own weight. Since the stabilizing effect through the hy draulic binder (cement) is not yet pronounced at this point, the measures mentioned in claims 3 and 4 are either ge separates or seized in combination. According to claim 3 is in the binder mixture additionally contain a fast-acting binder, such as gypsum, as a solidification accelerator in a very short time - within about 3-10 minutes - the molded base mass stiffens. This stiffening effect is also achieved bar by adding a moisture-absorbing additive, such as Expanded clay or slate is used. This will make the binder matrix also removed so much moisture in a short time that it is so stiff on its own is that the element blanks can be released after a short time, without collapsing. It should be noted that this featured called stiffening effect through the influence of saturated steam in the hardening boiler like which is destroyed, but then already the hydraulic binder (Cement) has a shape-stabilizing effect.

In claim 5 is a recipe for the wall components according to the invention specified with which the aforementioned advantages are achieved.

A wall component according to the invention is preferably approximately as follows manufactured: First, the plastic, malleable base, consisting of the binder mixture of fine quartz sand or flour, hydrothermally harden Binder, water, cement and optionally gypsum and from the  Light aggregate manufactured. Then the basic mass is poured into a mold brings that from a pad and a sitting on it, open at the top and bottom NEN molding box is assembled.

The mold filling becomes due to the engagement of a press ram in the mold box if necessary using other compaction measures, such as shaking, Vibration of the shape or the like. Pressed until the desired height of the wall component is reached. The wall component then remains in the for stiffening Shape. As described, the addition of gypsum in the ground for the stiffening mass and / or the moisture absorbing properties of the lightweight aggregate responsible. The stiffening time is about 3-10 minutes. After that it will Wall component by pulling off the molding box and then lifting it off of the press ram. The wall is temporarily stored component in the hourly range, in which the shape stabilization of the wall construction element due to the crystal growth of the hydraulic binder (cement) is carried out. Then several wall components are placed in the hardening boiler retracted where they are under the influence of a saturated steam pressure of about 16 bar and Cure hydrothermally at a temperature of 160-220 ° C.

Due to the above-mentioned special design of the shape is a special rational and simple manufacture of the wall components possible. Each A wall element is assigned to a base, which is not only a shaped surface, son serves as a transport element in the further process steps. The one above and the molding box, which is open at the bottom, is a particularly simple molding it should be noted that wall components with a certain wall thickness and length in different target heights by a corresponding measure of Mold filling can be produced in one and the same mold box.  

By heating the wall components, the interim storage time before de their introduction into the hardening vessel can be drastically reduced. So that Capacity of the manufacturing plant for the wall components can be increased.

The wall components can be heated in different ways gene.

The basic mass can be a part of the water in the form of saturated steam before the Wed be fed. Heating the lightweight aggregates also for example using hot air or flue gases is possible. Attempts have been made shows that a combination of measures is particularly advantageous on the Re reduction in interim storage time.

The hardening kettle can be optimally used if several plates in particular shaped wall elements lined up and each standing upright be retracted into it because at the same time per loading of the hardening boiler a maximum number of wall components can be hardened. Correspond The energy expenditure per wall required for curing is accordingly minimal component.

The invention is explained in more detail with reference to the accompanying figures . Show it:

Fig. 1 is a schematic representation of the manufacture of a erfindungsge MAESSEN wall component,

Fig. 2 is a perspective view of a loaded trolley wall components for feeding the hardening tank,

Fig. 3 shows a schematic vertical cross section through a loaded hardness boiler and

Fig. 4 is a measurement diagram that shows the relative weight increase .DELTA.G / G _{0 of} the lightweight zuschlagstoffes by removing moisture from the binder mixture as a function of time.

According to Fig. 1, the production of the plate-shaped wall segment ( 1 ) begins with the preparation of the plastic, moldable base material ( 2 ). This contains quartz powder ( 3 ), quicklime ( 4 ), Portland cement ( 5 ) and expanded clay ( 6 ) as light aggregate as components. These components are stored in appropriate silos ( 7 ), from where they reach the main mixer ( 10 ) in the appropriate composition with the addition of water ( 8 ) via the corresponding conveyors ( 9 ). It should be noted that the quicklime ( 4 ) in a reactor ( 11 ) is extinguished by adding water and is introduced into the main mixer ( 10 ) in the form of a pulpy lime sludge.

The following composition is used to produce a volume of 1 m ^{3 of} compressed compacted base material ( 12 ):

• About 1200 l expanded clay with a bulk density of 300-450 kg / m ³ and a grain size of about 4 mm to 8 mm,
• - approx. 150 kg quartz flour ( 3 ),
• - approx. 25 kg ground quicklime ( 4 ),
• - approx. 25 kg of Portland cement ( 5 ) and
• - approx. 130 l water ( 8 ).

It should be noted that expanded clay is also the next following grain size class (8 mm to 16 mm) is used or can be added.

According to Fig. 1a) the water ( 8 ) to the main mixer ( 10 ) is partially supplied in the form of saturated steam, for which purpose the steam generator ( 13 ) the main mixer ( 10 ) is switched on. The expanded clay ( 6 ) is fed to the main mixer ( 10 ) in a heated form by a flue gas heater ( 14 ). Both measures serve to shorten the interim storage time (see Fig. 1f)).

The ready-mixed base material ( 2 ) is introduced in the next production step b) into the mold ( 15 ), which is composed of a base ( 16 ) and the mold box ( 17 ) open and open at the top and bottom. After filling the mold ( 15 ) to the desired fill level, the ram ( 18 ) moves from above into the mold box ( 17 ) and presses the base material ( 2 ).

By applying further compaction measures, such as shaking (indicated by the double arrow 19 in FIG. 1c)) of the mold ( 15 ), the bulk-pored, compressed, compacted base material ( 12 ) is created. After completion of the compression, the Preßstem pel ( 18 ) remains in the mold ( 15 ) and continues to act on the compacted base material ( 12 ), which remains for a few minutes to stiffen their binder matrix in the mold ( 15 ). As a guideline, a time of 3-10 minutes can be mentioned, whereby a shortening of this stiffening time can be achieved by heating both the water ( 8 ) fed into the main mixer ( 10 ) and the expanded clay ( 6 ).

After the stiffening time, the wall segment ( 1 ) by pulling the molding box ( 17 ) and then lifting the ram ( 18 ) can be switched ent up ( Fig. 1e)). The compressed basic mass ( 12 ) is now so stiff that a collapse of the wall segment ( 1 ) under the influence of its own weight is no longer to be feared.

The demoulding is followed by intermediate storage of the wall segments ( 1 ), during which the binder matrix of the compacted base material ( 12 ) is to be further stabilized by the crystal growth of the Portland cement. The wall segments ( 1 ) thus become resistant to the influence of saturated steam in the hardening vessel ( 20 ). The intermediate storage time is approximately in the hour range, a reduction in turn can be achieved by the aforementioned heating of the water ( 8 ) and the expanded clay ( 6 ).

As can be seen from FIGS. 1f), 2 and 3, the individual wall segments ( 1 ) are still on the base ( 16 ), being carried out by a suitable conveyor device, not shown, from the molding press ( 15 ) to the trolley ( 21 ) are transported, where they are lined up and arranged upright with one of their narrow sides on the standing under.

After the interim storage period ( Fig. 1f)) the trolleys ( 21 ) with the wall segments ( 1 ) are moved into the hardening tank ( 20 ). Here they remain for a period of 4-8 hours and cure hydrothermally under the influence of a saturated steam pressure of about 16 bar and a temperature of 160-220 ° C. Due to the high-density structure of the compacted base mass, the hot saturated steam acts almost simultaneously in all volume areas of the wall segments ( 1 ), which means that, despite their low thermal conductivity, uniform and quick curing takes place.

The emptying of the hardening vessel ( 20 ) is not shown in FIG. 1. The finished wall segments ( 1 ) can be temporarily stored or transported directly to the building site.

The diagram according to Fig. 4 shows the relative weight increase G / G ₀ of the vermisch th with the binder mixture the expanded clay as a function of time after the vermi rule in the main mixer (10). The weight gain of the expanded clay is due to its moisture-absorbing effect, which means that it extracts water from the binder mixture and stiffens the binder matrix. The three graphs A, B and C represent the temporal course of the water withdrawal from the mixture of binders by the expanded clay with the following parameters:
A: cold water and expanded clay;
B: water temperature = 70 ° C, expanded clay cold;
C: water temperature = 70 ° C, expanded clay temperature = 200 ° C.

As can clearly be seen, the dehydration is most pronounced when using hot water and hot expanded clay, which results in a particularly short stiffening time. The interim storage time before the wall segments ( 1 ) are introduced into the hardness sel ( 20 ) can thereby be drastically reduced.

Reference list

1

Wall segment

2nd

Basic dimensions

3rd

Quartz flour

4th

Quicklime

5

Portland cement

6

Expanded clay

7

silo

8th

water

9

Conveyor

10th

Main mixer

11

reactor

12th

compacted basic mass

13

Steam generator

14

Flue gas heating

15

Molding press

16

document

17th

Molded box

18th

Ram

19th

Double arrow

20th

Hardening kettle

21

Trolley

Claims (5)

1. Insulating wall component, such as building block, plate-shaped wall segment ( 1 ) or the like. With a heap-porous concrete structure, molded from a base material ( 2 ) containing

• - a mixture of binders
• - From a hydrothermally curing binder, and
• - From fine quartz sand or flour ( 3 ), as well
• - A heat-insulating, coarse-grained lightweight aggregate with a grain size of 4-16 mm, which is silicate-bound in the matrix formed by the binder mixture by hydrothermal curing.

2. Wall component according to claim 1, characterized in that the binder mixture additionally contains a long-term and against the softening by steam influence, stabilizing hydraulic binder ( 5 ). 3. Wall component according to claim 1 or 2, characterized in that the binder mixture additionally contains a fast-acting binder as a solidification accelerator for the compression-molded, compressed base material ( 12 ). 4. Wall component according to one of the preceding claims,  characterized, that the lightweight aggregate is a moisture-absorbing aggregate. 5. Wall component according to one of the preceding claims, characterized by, the following composition of the basic mass based on a volume of 1 m ^{3 of} compression-molded, compressed, bulk-porous basic mass ( 12 ):

• 1200 l expanded clay ( 6 ) with a bulk density of 300 to 450 kg / m ³ and a grain size of 4 mm to 16 mm,
• - 150 kg quartz flour ( 3 ),
• - 25 kg of ground quicklime ( 4 ),
• - 25 kg of Portland cement ( 5 ) and
• - 130 l of water ( 8 ).