DE3816686A1 - Thermally insulating wall component and process for the production thereof - Google Patents

Abstract

The invention relates to a thermally insulating wall component, such as a brick, a tabular wall segment (1) or the like, which is pressure-moulded from a base composition (2). The latter contains a binder mixture of a hydrothermally curing binder, such as burnt lime (quick lime) (4) or hydrated lime (slaked lime, calcium hydroxide) and of fine quartz sand or flour (3). Furthermore, the base composition (2) contains a thermally insulating light-weight aggregate (expanded clay 6) which is silicate-bonded in the matrix formed from the binder mixture by hydrothermal curing. The light-weight aggregate (expanded clay 6) for forming a no-fines texture of the component microstructure is coarse and of uniform grain size. <IMAGE>

Description

The invention relates to a heat-insulating wall structure ment with the specified in the preamble of claim 1 level composition and a method for its Manufacturing. Among the building blocks are building blocks ne in various formats, plate-shaped wall segments or even industrially prefabricated buildings Understand interior and exterior walls. The invention subject or the inventive method especially with regard to the production of plat ten-shaped wall segments in common masonry thicknesses developed from 5-37.5 cm. The length and height dimensions solutions of these wall segments amount to a multiple usual bricks. You will especially at the so-called "casament" (= limestone-sandstone element) - Construction method used, with all building exterior and - inner walls divided into segments in the planning stage, industrially pre-selected in the desired dimensions manufactures, transported to the construction site and there after Plan to be put together to the building. Compared to the traditional stone-to-stone walls result from the casament construction a significantly shorter construction time.

Traditionally, the casement wall segments from individual ones that are put together accordingly industrially prefabricated on the glued sand-lime bricks does. For a better understanding of the invention should here first briefly the usual manufacturing process for Lime sandstones are outlined:  

The raw materials - lime and quartz sands - are dosed according to weight or volume, mixed intensively with each other and fed into the reaction container 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. This is followed by hardening of the blanks at temperatures of 160-220 ° C under a saturated steam pressure of about 16 bar in so-called hardeners. The hardening process takes about 4-8 hours. After hardening and cooling, the sand-lime bricks are ready to use.

A particular disadvantage of the sand-lime bricks lies in their low thermal insulation, which of course also the wall components made from it apply. Around Here The binder can achieve an improvement mixture of the hydrothermally curing binder (Quicklime or hydrated lime) and the fine quartz sand or flour is a heat-insulating, granular lightweight aggregate be mixed into the fabric. This is in the bandage Mixture of medium formed by hydrothermal curing silicate-bound matrix.

In the case of the lime sandstone production Manufacture of heat-insulating wall components Problems with hardening occur in the aforementioned manner in the hardening kettle. Thanks to the heat-insulating light-weight impact is the wall component so bad heat conductive that the heat required for curing only very slowly down to the core of the wall components penetrates. Those in house construction for energy reasons beneficial thermal insulation causes in the manufacture the wall components are exactly the opposite. To one To achieve uniform curing would now be one drastically increased dwell time of the wall components in the  Hardening kettle necessary, which is a much lower Re capacity of the production plant with increased energy energy consumption. This is out of operation not economically viable.

Proceeding from this, the invention is based on the object de, a heat-insulating wall component of the beginning mentioned type so that the usual dwell time in the hardening kettle not exceeded and thus the disadvantages mentioned above can be avoided.

The basic solution to this problem is indicated in the character of claim 1. Accordingly, the granular lightweight aggregate has a grain size of at least about 4 mm to form a large-scale structure of the component structure. This means concretely that the light aggregate is practically free of fine grain sizes. The thus created heap porous structure of the component structure means that even after compression in the element forming the basic wall element , interconnected air channels - so-called air gussets - are formed, which are also connected to the component environment. The external characteristic of such a structure with a lot of pores is the air permeability of the element. It therefore has a very low vapor diffusion resistance.

For hydrothermal steam treatment in the hardening boiler the saturated steam now comes as a result of the high partial Vapor pressure gradient across the air channels immediately and directly into the interior of the wall components and heats them up based on their total volume moderate. This also applies to thick-walled components. The common, known from the sand-lime brick production Residence time in the hardening kettles is also sufficient the wall components according to the invention to the full hardening.  

The addition of the heat-insulating lightweight aggregate material poses further problems, particularly in the production of large-scale, clumping wall components. In contrast to the actual lime sand stone production, where the base material has such a high degree of inherent stability after being pressed that the blanks are stacked on top of one another that they can be stacked on top of one another and introduced into the hardening boiler and remain dimensionally stable there under the influence of saturated steam, the heat-insulating wall components are their pore structure less inherently stable. In particular, the binder matrix is over-moistened by the flow of saturated steam in the hardening kettle and thus softened. Due to this low inherent stability, it would actually be necessary that each wall construction element in a stabilizing mold box - which could then be stacked one on top of the other - or individually and flat lying on a trolley is inserted into the hardening boiler. Both options are prohibited for business reasons. With the former, the extremely cost-intensive purchase of a large number of mold boxes would be necessary, with the latter, the utilization of the hardening kettle is prohibitively low.

For an optimal utilization of the capacity of the hardening kettles in particular, plate-shaped wall segments are said to be high edge on one of its narrow sides standing on one usual trolleys for sand-lime brick production can be arranged at a short distance from each other nen. However, this requires a certain degree of inherent stability the freshly pressed wall segment elements so that they can also be influenced by saturated steam in the The hardness kettle remains true to form. According to An saying 2 achieved in that the binder mixture a hydraulic binder, such as cement which is the not yet hydrothermally hardened  Lime component of the binder matrix against the stabilized by the influence of steam. The cement be namely has a solidification through its crystal growth development of the structure of the component structure total Since this solidification is also influenced by Water vapor remains irreversible, can in the Hardening kettle placed on one of its narrow sides standing components the process of hydrothermal Survive hardening safely.

With regard to a process that is as rational as possible - which means, among other things, the fastest possible manufacture and the lowest possible number of manipulations of the production object - it must be demanded that, in addition to the rapid curing, 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 entry position into the hardening vessel - namely standing on its narrow side - can leave the molding press. This in turn requires that the element blanks shortly after compression molding have such a high level of inherent stability that they can carry their own weight. Since the stabilizing effect by the hydraulic binder (cement) is not yet pronounced at this point in time, the measures mentioned in claims 3 and 4 are either separated or taken in combination. According to claim 3, the binder mixture additionally contains a fast-acting binder, such as gypsum, which as a setting accelerator in a very short time - within about 3-10 minutes - stiffens the molded base. This stiffening effect can also be achieved by using a moisture-absorbing additive, such as expanded clay or slate, as a light aggregate. This also removes so much moisture from the binder matrix in a short time that it becomes so stiff on its own that the element blanks can be released after a short time without collapsing. It should be noted that the aforementioned stiffening effect is nullified by the influence of saturated steam in the hardening kettle, but then the hydraulic binder (cement) already has a shape-stabilizing effect.

In claim 5 is a recipe for the Invention appropriate wall components specified with which the front mentioned advantages can be achieved.

In claim 6, the inventive method for Production of a wall component according to one of the An sayings 1-5 specified. Accordingly, the plasti formable base, consisting of the bindemite mixture of fine quartz sand or flour, hydro thermal curing binder, water, cement as well if necessary, plaster and from the lightweight aggregate produced. After that, the basic mass is in a mold brought in from a pad and one on it seated, open bottom and top molding box together is set.

By engaging a press ram in the molding box the mold filling is used if necessary further compaction measures, such as shaking, vibration the shape or the like pressed until the target height of the wall construction element is reached. Then that remains Wall component for stiffening in the form. As described For the stiffening, the addition of plaster in the Base mass and / or the moisture-absorbing properties responsible for the light aggregate. The Stiffening time is about 3-10 minutes. After that it will Wall component by pulling the molding box and after following lifting of the press ram. It there is an intermediate storage of the wall elements  tes in the hour range at which the shape stabilization tion of the wall component through crystal growth of the hydraulic binder (cement) becomes. After that, several wall components are placed in the Hardness boiler retracted, where they are influenced by a Saturated steam pressure of about 16 bar and a temperature Cure hydrothermally from 160-220 ° C.

As characteristic features of the specified in claim 6 Procedure b) -f) are to be used consider. This is due to the special design tion of the shape according to feature b) a particularly rational le and simple manufacture of the wall components possible. A base is assigned to each wall component, not just as a shaped surface, but as a transport element serves in the further process steps. The Mold box open at the top and bottom is a special one simple form element, it should be noted that Wall components with a certain wall thickness and -length in different target heights by an ent speaking measure of the mold filling in one and the same Molding boxes can be made.

By heating the wall as specified in claim 7 components can be the interim storage time before their installation bring in the hardening kettle drastically reduced who the. So that the capacity of the manufacturing plant for the wall components can be increased.

The claims 8-10 characterize different procedures opportunities such as wall components necessary heat is supplied to their heating can. Accordingly, the basic mass can be part of the water in the form of saturated steam before mixing the. Heating the light aggregates (An Proverb 9) for example using hot air or smoke  gas (claim 10) is possible. Attempts have been made shows that a combination of the in claims 8-10 specified measures are particularly advantageous the reduction of the interim storage time affects.

Claim 11 again explicitly specifies the arrangement of the Wall components for insertion in the hardening vessel. This means that it can be used optimally, as per Be sending the hardening kettle at the same time a maximum Number of wall components can be hardened. Ent the necessary for hardening is extremely minimal ge energy expenditure per wall component.

The invention is illustrated by the attached figures explained in more detail. Show it:

Fig. 1 component is a schematic representation of the method according proper for manufacturing a wall,

Fig. 2 is a perspective view of a loaded trolley wall components to Be destiny of the hardening tank,

Fig. 3 shows a schematic vertical cross section through a charged hardening vessel and

Fig. 4 is a measurement diagram that shows the relative weight gain Δ G / G ₀ of the lightweight aggregate by removing moisture from the binder mixture as a function of time.

According to Fig. 1, the production of the plate-shaped gene wall segment ( 1 ) begins with the preparation of the plastic, mouldable matrix ( 2 ). This contains quartz powder ( 3 ), quicklime ( 4 ), Portland cement ( 5 ) and expanded clay ( 6 ) as light aggregate. These components are stored in appropriate silos ( 7 ), from where they arrive in the appropriate mix with the addition of water ( 8 ) via the appropriate conveyors ( 9 ) in the main mixer ( 10 ). 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)).

In the next manufacturing step b), the completely mixed basic mass ( 2 ) is introduced into the mold ( 15 ), which is composed of a base ( 16 ) and the mold box ( 17 ), which is 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 conveyed from the molding press ( 15 ) by a suitable conveyor device, not shown Trolleys ( 21 ) are transported, where they are lined up and arranged upright with one of their narrow sides standing on the base.

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, they harden quickly and evenly.

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

The diagram according to Fig. 4 shows the relative weight increase w / w ₀ of 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 based on its moisture-absorbing effect, whereby it removes 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 be drastically reduced as a result.

Reference number:

1 wall segment
2 basic dimensions
3 quartz flour
4 quicklime
5 Portland cement
6 expanded clay
7 silo
8 water
9 conveyor
10 main mixers
11 reactor
12 compacted base mass
13 steam generators
14 flue gas heating
15 molding press
16 pad
17 molded box
18 ram
19 double arrow
20 hardening kettles
21 trolleys

Claims (12)

1. Heat-insulating wall component, such as building block, plat-shaped wall segment ( 1 ) or the like. Compressed from a base material ( 2 ) containing

• - a mixture of binders
  • - From a hydrothermally curing binder, such as quicklime ( 4 ) or hydrated lime, and
  • - From fine quartz sand or flour ( 3 ), as well
• - a heat-insulating, granular lightweight aggregate,
  • the silicate is bound in the matrix formed by the binder mixture by means of hydro-thermal curing,

characterized in that the component has a pore structure and the light aggregate has a grain size of at least about 4 mm. 2. Wall component according to claim 1, characterized in that the binder mixture additionally contains a binder medium matrix in the long term and in particular against softening by the influence of steam, hydraulic binder, such as Portland cement ( 5 ). 3. Wall component according to claim 1 or 2, characterized in that the binder mixture additionally contains a fast-acting binder, such as gypsum, as a solidification accelerator for the compression-molded, compressed base mass ( 12 ). 4. Wall component according to one of the preceding claims, characterized in that a moisture suction of the additive, such as expanded clay ( 6 ) or slate is contained as a light aggregate. 5. Wall component according to one of the preceding claims, characterized by the following composition of the base material based on a volume of 1 m ^{3 of} molded, compressed, aggregate-based base material ( 12 ):

• About 1200 l of light aggregate, such as expanded clay ( 6 ) with a bulk density of 300 to 450 kg / m ³ and a grain size of at least about 4 mm,
• - approx. 150 kg quartz flour ( 3 ),
• - approx. 25 kg ground quicklime ( 4 ),
• - approx. 25 kg of hydraulic binder, such as Portland cement ( 5 ) and
• - approx. 130 l water ( 8 ).

6. A method for producing a wall component according to one of the preceding claims with the following method steps:

• a) Production of the plastic, mouldable basic mass ( 2 ) consisting of fine quartz sand or flour ( 3 ), hydrothermally curing binder, water, hydraulic binder (Portland cement 5 ) and optionally gypsum as a binder and from the lightweight aggregate ( Expandable clay 6 ),
• b) introducing the base mass ( 2 ) into the shape of a molding press ( 15 ), which shape is composed of a base layer ( 16 ) and a molding box ( 17 ) sitting on it, open at the top and bottom,
• c) pressing the mold filling by engaging a press ram ( 18 ) in the molding box ( 17 ) and, if necessary, by applying further compression measures, such as shaking, vibration of the mold or the like, until the desired height of the wall component (wall segment 1 ) is reached,
• d) stiffening of the wall component (wall segment 1 ) in the form,
• e) demoulding the wall component (wall segment 1 ) by pulling off the molding box ( 17 ) and then lifting the press ram ( 18 ),
• f) intermediate storage of the wall component (wall segment 1 ),
• g) moving the wall component (wall segment 1 ) into the hardening vessel ( 20 ),
• h) hydrothermal curing of the wall component (wall segment 1 ) under the influence of a saturated steam pressure of about 16 atmospheres and a temperature of 160 to 220 ° C in the hardening vessel ( 20 ).

7. The method according to claim 6, characterized in that the wall components (wall segment 1 ) for reducing the stiffening and intermediate storage time are heated. 8. The method according to claim 7, characterized in that the basic mass ( 2 ) is supplied with a portion of the water ( 8 ) in the form of saturated steam. 9. The method according to claim 7, characterized in that the light aggregate (expanded clay 6 ) before Einbrin gene in the main mixer ( 10 ) is heated. 10. The method according to claim 9, characterized in that the light aggregate (expanded clay 6 ) by means of hot air or flue gases (flue gas heater 14 ) it is heated. 11. The method according to any one of claims 6 to 10, characterized in that a plurality of wall components and in particular plat-shaped wall segments ( 1 ) strung together vertically because Weil on one of their narrow sides on the base ( 16 ) standing in the hardening vessel ( 20 ) are retracted.