METHOD FOR PRODUCING HYDROTHERMALLY HARDENED PORECTOR OR FOAM CONCRETE FORM BODY

Description

[0001] The present invention relates to a process for producing low-sulfate, preferably sulfate-free, hydrothermally cured aerated or foam concrete moldings, in particular in the form of aerated or foam concrete blocks. Particular preference is given to producing aerated concrete blocks of standardized grades with regard to strength and bulk density according to DIN EN 771-4:2015-11 in combination with DIN 20000-404:2018-04 with bulk densities of 305 to 1000 kg / m 3 . However, non-standardized blocks, e.g., with a bulk density between 200 and < 305 kg / m 3 , and aerated or foam concrete insulation material, preferably aerated or foam concrete insulation boards, with a bulk density between e.g., 70 and < 200 kg / m 3 , preferably 70 and 150 kg / m 3 . Furthermore, reinforced aerated or foam concrete precast elements with bulk densities such as standardized or non-standardized aerated or foam concrete blocks can also be produced.

[0002] Aerated concrete moldings consist of hydrothermally cured, porous calcium silicate hydrate material. They are produced from an aqueous mixture or fresh concrete mass containing at least one CaO component reactive in the hydrothermal process and at least one SiO2 component reactive in the hydrothermal process, a blowing agent, in particular aluminum powder and / or paste, and optionally additives, particularly inert ones. Furthermore, the fresh concrete mass often contains at least one admixture, e.g., a plasticizer and / or a dispersant. The pourable or ready-to-cast fresh concrete mass is poured into a mold, allowed to expand and stiffen, cut, and then subjected to steam curing. In contrast to conventional, non-autoclaved concrete, aerated concrete material does not contain coarse aggregates with a grain size > 2.0 mm.

[0003] To produce hydrothermally cured foam concrete moldings, pre-formed foam is mixed into the fresh concrete mass instead of the blowing agent, or the fresh concrete mass containing a foaming agent is directly foamed by stirring, and then the pourable or ready-to-cast fresh concrete mass is poured into the mold. In both cases, the blowing process is omitted.

[0004] Conventional porous and foam concrete moldings essentially consist of a solid web framework consisting primarily of calcium silicate hydrate phases (CSH phases). Primarily means that the solid web framework consists of more than 50 mass% CSH phases based on its dry mass. At high bulk densities, e.g. > 650 kg / m³< , the content can also be less than 50 mass%. The solid web framework can also contain, for example, residual quartz grains and, if applicable, inert additives. The residual quartz grains and the inert additives are embedded in the CSH phases. The solid web framework has webs that surround the pores (= macropores) artificially created by porosification or the addition of foam or foaming. In addition, the solid web framework has nano-, gel- and micropores that are embedded in or distributed within the CSH phases. The nano-, gel- and micropores are part of the solid web framework.The CSH phases of the solid-state framework thus act as a binding phase within the solid-state framework. They are mostly cryptocrystalline to crystalline, typically CSH(I) and predominantly 11 Å tobermorite.

[0005] Aerated or foam concrete blocks are building blocks made of aerated or foam concrete material. These generally unreinforced aerated or foam concrete blocks are primarily used as masonry units. Depending on the manufacturing tolerances, they are also referred to as aerated or foam concrete blocks or blocks.

[0006] Reinforced aerated or foam concrete moldings are mainly used as large-format aerated or foam concrete components.

[0007] Pore- As already explained, foam concrete moldings with very low bulk density are used as porous or foam concrete insulation bodies, preferably in the form of porous or foam concrete insulation boards.

[0008] Currently, aerated concrete blocks of standardized grades (EN 771-4 2015-11 and DIN 20000-404:2018-04) with bulk densities ≤ 800 kg / m 3 < are generally manufactured using so-called lime-cement formulations. Lime-cement formulations contain cement, usually Portland cement (CEM I), as both a CaO and SiO 2 component. However, lime-cement formulations can also contain other standardized (e.g., CEM II or CEM III) or non-standardized cements. In addition to cement, quicklime and / or hydrated lime are also included as a CaO component. In addition to cement, lime-cement formulations also contain another SiO 2 component, e.g., ground quartz, preferably ground sand, or fly ash. Furthermore, lime-cement formulations usually contain a sulfate carrier in the form of anhydrite and / or gypsum. The sulfate carrier in the cement acts as a setting regulator and is already contained in the cement.For standardized cements, the SO3 content is specified in DIN EN 197-1:2011-11. However, an additional sulfate carrier is usually added to the aerated concrete mix.

[0009] The setting regulator in the cement serves to adjust the setting time of the concrete; the mix may contain other additives that influence the setting time. The addition of the setting regulator to the cement ensures that the supply of water-soluble sulfate at the beginning of hydration is just high enough for the hydrating tricalcium aluminate component to bind exclusively as trisulfate. Without the sulfate carrier in the cement, however, a freshly mixed cementitious mixture would immediately solidify, as the tricalcium aluminate would immediately form large, leaf-shaped tetracalcium aluminate hydrate crystals, which would then grow together in the space between the cement particles filled with mixing water to form a house-of-cards-like structure. This phenomenon is known as "spoon binder."

[0010] In the production of aerated or foamed concrete moldings, the added sulfate carrier also serves to promote the formation of tobermorite from hydroxyl ellastadite. This is because the CSH phases (mainly CSH-I and CSH-II) that form from the cement clinker in the green state of the aerated concrete cake can be converted into hydroxyl ellastadite by the sulfate carrier, which can then form tobermorite during further autoclaving (see Schober ZKG International H.7 2005 Vol. 58, p. 63ff.).

[0011] Various processes for producing aerated or foamed concrete moldings from lime-cement formulations and also from pure cement formulations are known in the art. WO 98 / 02391 A1, for example, describes a process for producing aerated concrete. The rapidly setting mixture used comprises an SiO 2 component, quicklime, a blowing agent, gypsum, cement, and water. To reduce the reactivity of the quicklime, lignin sulfonate, for example, is added. Furthermore, a polyacrylate (Dispex N 40 V from BASF) can be used as a dispersant.

[0012] CN 102 757 211 A, for example, discloses a process for producing aerated concrete block. The mixture used for this purpose contains, among other ingredients, 2 to 4 mass% cement clinker and 1 to 3 mass% gypsum.

[0013] EP 2 371 783 A1 relates to a preformed aerated concrete body and a method for its production. The cementitious casting compound used for its production contains an additive to prevent sedimentation. This additive is a polysaccharide and / or polyethylene glycol and / or polyethylene oxide and / or a melamine resin derivative. According to EP 2 371 783 A1, any other additives can also be added, e.g., polyacrylic acid and a dispersant.

[0014] CN 104 628 416 A discloses a process for producing aerated concrete made from a mixture containing 10 to 15 mass% cement clinker and 3 to 6 mass% calcium sulfate.

[0015] CN 107 963 903 A also discloses a process for producing an aerated concrete block, wherein the mixture for producing the aerated concrete block contains 6 to 12 mass% cement clinker and 3 to 6% natural gypsum.

[0016] CN 106 045 561 A discloses a method for producing aerated concrete block. The mixture used to produce the aerated concrete block contains 2 mass% cement clinker and 3 mass% gypsum.

[0017] CN 102 757 211 A also describes a process for producing aerated concrete block. The mixture used for production contains 2 to 4 mass% cement clinker and 1 to 3 mass% gypsum.

[0018] However, lime-cement formulations are known to have disadvantages. For example, the addition of gypsum can lead to lime grit in the fresh concrete, the negative effects of which are well known.

[0019] The most significant disadvantage of aerated and foamed concrete blocks made from lime-cement formulations and cement formulations is that they contain sulfate from the Portland cement and / or the anhydrite / gypsum additive in the initial mix. This sulfate can leach out. This complicates the recycling of construction waste and demolition material from aerated concrete because the sulfate limit for use in landscaping is not met. Furthermore, under certain conditions during construction, sulfate ions can react with calcium silicate hydrate phases of the mineral mortar used to form ettringite (3 CaO x Al2O3 x 3 CaSO4 x 32 H2O) or thaumasite (CaSiO3 x CaSO4 x CaCO3 x 15 H2O). This ettringite / thaumasite formation destroys the building material bond through crystallization accompanied by volume expansion in the mortar joint. The only effective countermeasure is the use of sulfate-resistant mortars.

[0020] Furthermore, pure lime formulations for the production of aerated concrete moldings are also known in the field. These lime formulations contain only quicklime and / or hydrated lime as the CaO component, but no cement or cement clinker. Consequently, they do not contain a sulfate carrier as a setting regulator, thus avoiding the aforementioned problems.

[0021] WO 2009 / 121635 A1, for example, discloses two processes for the hydrothermal production of aerated concrete or foamed concrete moldings from a lime formulation. It was discovered that, with lime formulations, it is not the stiffened, cuttable consistency of the cake that is important, but rather the water content of the aerated concrete cake before it is placed in the autoclave. The problem is that the water seeps to the bottom during autoclaving and collects there. This makes the lower region of the aerated concrete cake unstable, and the aerated concrete cake can collapse. WO 2009 / 121635 A1 therefore addresses measures to immobilize the water in the aerated concrete cake during autoclaving.

[0022] According to a first method, according to WO 2009 / 121635 A1, the aerated concrete cake is tilted onto a side wall of the mold after it has stiffened and cut. It thus stands upright during cutting. After cutting, the cake is tilted back onto its wide side and autoclaved on a curing grid. Due to the tilting and the relatively low load when the aerated concrete cake is stored on its wide side, less water seeps downwards, so that the aerated concrete cake is less softened in its lower area.

[0023] A second process, according to WO 2009 / 121635 A1, uses highly dispersed silica, which largely immobilizes the water. This allows the aerated concrete cake to be autoclaved upright.

[0024] CH 499 469 discloses, within the scope of an embodiment not according to the invention, the production of a gas concrete molded body from a fresh mass which, based on the dry components, comprises 64% by mass of sand, 21% by mass of fine white lime and 15% by mass of hydrated lime.

[0025] EP 3 235 794 A1 also discloses a low-sulfate aerated concrete, as well as a mixture and a process for its production. The aerated concrete consists of 25 to 65 wt.% quartz powder, 5 to 30 wt.% aerated concrete waste, 0 to 40 wt.% cement, 5 to 25 wt.% quicklime, 0 to 15 wt.% ground aerated concrete, 0.05 to 0.4 wt.% aluminum component, 0 to 5 wt.% of a sulfate carrier, such as anhydrite or gypsum, 0 to 15 wt.% calcined clay (CT) and / or 0 to 15 wt.% high-fired clay (AT), and water. The sum of CT and AT is at least 1.5 wt.%, and the aerated concrete exhibits leaching behavior that results in a sulfate concentration of no more than 500 mg / l sulfate in the eluate. In addition, the aerated concrete exhibits a total hygric shrinkage of 0.4 mm / m or less. The specified mass percentages refer to the dry mass of the mix. The objective of EP 3 235 794 A1 is to keep the cement content as low as possible and to eliminate the sulfate carriers previously used.According to EP 3 235 794 A1, the cement and the sulfate carriers are replaced as completely as possible by the calcined clay (CT) and / or the amorphous clay (AT).

[0026] Furthermore, sulfate-carrier-free formulations are known in the field of conventional concrete / mortar technology: RU 2159754 C2, for example, discloses the production of a non-autoclaved lightweight concrete. The mixture used to produce the lightweight concrete contains ground cement clinker and a foaming agent without the addition of gypsum.

[0027] DE 10 2006 038743 A1 discloses the use of a solid composition for producing a tile adhesive. The solid composition comprises a sulfate-free Portland cement clinker flour, a mortar retarder, a cellulose ether, and optionally other components for producing a tile adhesive.

[0028] EP 1 072 566 A1 deals with a fast-setting, hydraulic binder mixture and a process for its production. The binder mixture is used for the production of concrete. It also contains a sulfate-carrier-free hydraulic binder component, in particular one ground without sulfate carriers, and a component for accelerating hardening. To control early strength and early strength development, it contains both sodium carbonate and potassium carbonate in proportions tailored to the specific application. A setting-retarding component in the form of a sulfonic acid group is also present. The sulfate-carrier-free binder component can be sulfate-carrier-free Portland cement clinker flour.

[0029] DE 198 54 477 A1 discloses a fast-setting hydraulic binder composition containing a sulfate-free binder component and a sulfonate-free superplasticizer. The sulfate-free binder component can be Portland cement clinker flour. The sulfonate-free superplasticizer can be a polycarboxylate, which also has a dispersing effect. The binder mixture of DE 198 54 477 A1 is used, for example, as a sprayable binder or for the production of shotcrete or mortar.

[0030] DE 101 41 864 A1 discloses a rapid-setting cement binder mixture for rapid-hardening concrete. The binder mixture has a controllable working time and rapidly increasing strength after the end of the working time. The binder mixture comprises a sulfate-free binder component with ultrafine Portland cement clinker powder and an agent that ensures structural viscosity. The agent that ensures structural viscosity includes, for example, gluconic acid and its salts. To prevent excessively rapid setting, the binder mixture also contains retarders.

[0031] DE 196 33 447 A1 discloses a fast-setting hydraulic binder mixture made from ground Portland cement clinker with high sulfate resistance. The binder mixture also contains an inorganic setting accelerator and a setting retarder. The setting retarder is either a system consisting of an organic agent that promotes strength and inhibits the growth of calcium aluminate carbonate hydrates and / or an additional functional agent, with the ratio of the two components being 1:0.83 to 1:6. The binder mixture is used for the production of sprayed mortar or sprayed concrete.

[0032] The object of the present invention is to provide a process for producing low-sulfate to sulfate-free, hydrothermally cured porous and / or foam concrete moldings, which can be processed simply and flexibly using conventional process steps and ensures good mechanical and hygric properties, in particular good strength properties, of the produced porous and / or foam concrete moldings. In particular, the process should enable the use of existing machinery and equipment.

[0033] This object is achieved by a method having the features of claim 1. Advantageous developments of the invention are characterized in the subsequent subclaims.

[0034] The invention is explained in more detail below using a drawing as an example. The drawings show: Figure 1: Determined A-numbers and amorphous phase content plotted against the C / S ratio of a first test series Figure 2: Measured slumps of a fourth test series Figure 3: Determined A-numbers of the fourth test series

[0035] Within the scope of the invention, it was surprisingly discovered that it is possible to produce porous and / or foam concrete moldings from a fresh concrete mass that contains Portland cement clinker flour but no sulfate carrier as a setting regulator. Portland cement clinker flour is pure ground Portland cement clinker without the addition or, in particular, without the addition of sulfate carriers, so-called spoon binders. According to the invention, the fresh concrete mass therefore contains no cement containing sulfate carriers, but only sulfate-free Portland cement clinker flour. Nevertheless, the fresh concrete mass does not set immediately and is, surprisingly, processable.

[0036] According to the invention, the fresh concrete mix preferably contains no additive consisting of magnesium carbonate. Minor minor components or impurities of magnesium carbonate may, of course, be present in the fresh mix.

[0037] In the context of the invention, sulfate carrier-free means that no sulfate carrier is added to the fresh concrete mass or to any of the individual components / raw materials of the fresh concrete mass.

[0038] For the purposes of the invention, a sulfate carrier is understood to be a raw material consisting of alkali metal sulfate or alkaline earth metal sulfate, preferably calcium sulfate. Examples include gypsum or anhydrite. Of course, these raw materials may contain minor components or impurities. Minor components are undesirable and should therefore be considered impurities.

[0039] In contrast, raw materials which contain sulfate minerals or sulfate compounds only as minor components are not referred to as sulfate carriers in the context of the invention.

[0040] An example of such a raw material is sulfate-containing aerated concrete powder. Aerated concrete powder, if produced from a conventional lime-cement or cement formulation, does contain a certain amount of calcium sulfate. However, the aerated concrete powder does not consist of calcium sulfate; instead, it contains the alkali and / or alkaline earth sulfate only as a minor component or impurity.

[0041] Portland cement clinker flour may also contain sulfate minerals or sulfate compounds as secondary components. These may result, for example, from the natural raw materials and / or from the fuels used in clinker production.

[0042] However, the proportion of SO3 in the Portland cement clinker flour is preferably < 2.0 mass%, more preferably < 1.5 mass%, determined by infrared spectrometry using an Eltra CS-2000 from Eltra GmbH.

[0043] Even if the fresh concrete mix does not contain any added sulfate carrier according to the invention, the fresh concrete mix may still contain small amounts of sulfate, which is present as a contaminant in the raw materials used. These contaminants may have a geogenic or technological background (technological contaminants).

[0044] As already explained, recycled aerated concrete powder, which originates from the recycling of aerated concrete residues, can contain up to 8 mass% calcium sulfate. Consequently, the aerated or foam concrete moldings produced according to the invention can also contain small amounts of sulfate. However, due to the lack of the addition of a sulfate carrier, the aerated or foam concrete moldings produced according to the invention have a reduced and preferably very low sulfate concentration. In particular, they have a sulfate concentration of ≤ 100 mg / l, preferably ≤ 50 mg / l, in the eluate according to DIN EN 12457-4: 2003-01 (DEV S 4).

[0045] What was particularly surprising was that the aerated or foam concrete molded body could be produced in the conventional manner using known equipment. In particular, contrary to expectations, there was no excessively rapid setting (spoon binder). The mix is ​​readily processable, and the expansion process is not negatively affected. This is despite the fact that the slump is, as expected, significantly lower than with conventional formulations containing sulfate carriers. It would therefore have been expected that the expansion process would be hindered. However, the significantly higher water content of the casting mix or fresh concrete mix compared to the production of conventional, non-autoclaved concrete or mortar apparently ensures, among other things, that the fresh concrete mix remains processable.

[0046] The W / F value (water / solids value) of the fresh concrete mass is preferably 0.45 to 1.5, preferably 0.55 to 1.0, particularly preferably 0.60 to 1.0.

[0047] In addition, the fresh concrete mass preferably has a slump of 20 to 45 cm, more preferably 25 to 40 cm. The slump was measured according to industry standards. For this purpose, a metal ring with an inner diameter of 69 mm and a height of 59 mm is placed in the center of a glass plate and filled to the brim with fresh aerated concrete mass. Immediately afterwards, the ring is quickly lifted horizontally, and the fresh aerated concrete mass spreads out almost circularly. The diameter of the circle is measured twice perpendicular to each other, and the average value is recorded to the nearest 0.5 cm. Because the flowability of the fresh aerated concrete mass decreases very quickly due to the onset of hydrogen evolution, the slump determination must be completed within 60 seconds of pouring.

[0048] During the production of foam concrete moldings, the slump is measured before the fresh concrete mass containing the foaming agent is foamed.

[0049] The fresh concrete mass preferably also has a Portland cement clinker content of 5 to 45 mass%, preferably 10 to 35 mass%, particularly preferably 10 to 25 mass%, based on the total solids content (= total solids) of the fresh concrete mass. The solids content is understood to be the sum of all solids, i.e., the mass of the freshly added dry matter and the dry matter contained in the return sludge. The solids contained in admixtures or additives, such as flow agents or dispersants, and in the blowing agent or foaming agent, are not included in the total solids; their content is related to the solids content.

[0050] The dry matter contained in the return sludge consists of hydrate phases formed from the binder components and, if necessary, inert substances such as aerated concrete powder or rock powder. The hydrate phases have already reacted to such an extent that they no longer contribute to the green strength. They only react during hydrothermal curing in the autoclave.

[0051] The fresh concrete mass preferably contains 2 to 35 mass%, preferably 2 to 25 mass%, particularly preferably 2 to 20 mass%, very particularly preferably 2 to 17 mass% and even more preferably 10 to 15 mass%, of return sludge (dry mass) based on the solids content in the fresh concrete mass.

[0052] The return sludge stabilizes the fresh concrete mass and the green aerated or foamed concrete body. The CSH phases contained in the return sludge act as crystallization nuclei for the newly formed CSH phases from the binder components, especially the Portland cement clinker flour, which determine the green strength of the fresh aerated or foamed concrete body. This results in the side effect that, because the return sludge has already reacted, no additional exothermic energy is released through new phase formation in the system.

[0053] Portland cement clinker flour provides CaO and SiO 2 for the reaction in the autoclave. It is therefore both a CaO and SiO 2 component.

[0054] As an additional SiO 2 component, the fresh concrete mass also contains ground quartz, preferably ground quartz sand.

[0055] Quartz, preferably quartz sand, preferably makes up the majority of SiO 2 in the fresh concrete mass.

[0056] The fresh concrete mass preferably contains 25 to 80 mass%, preferably 30 to 70 mass%, particularly preferably 30 to 45 mass%, of ground quartz, based on the solids content of the fresh concrete mass. This ensures, in particular, the formation of a sufficient amount of CSH phases.

[0057] Fly ash as a SiO 2 component is preferably not included, since it usually contains sulfate as a minor component.

[0058] In addition, the fresh concrete mass contains quicklime and / or hydrated lime as an additional CaO component.

[0059] The fresh concrete mass preferably contains 5 to 25 mass%, preferably 10 to 25 mass%, particularly preferably 15 to 25 mass%, of quicklime based on the solids content of the fresh concrete mass. This ensures, in particular, the formation of a sufficient amount of CSH phases.

[0060] The fresh concrete mass may also contain other inert additives known in the art, preferably natural ground limestone flour and / or precipitated calcium carbonate (PCC) and / or aerated concrete flour. Aerated concrete flour is recycled, ground, hydrothermally hardened aerated concrete material. This can be obtained as sorted construction waste or directly after production. It is preferably produced according to the invention. Furthermore, it typically has a grain size of ≤ 1700 µm. Aerated concrete flour is also referred to in the art as aerated concrete chippings, aerated concrete fines, or undersize.

[0061] The fresh concrete mass preferably contains 0 to 60 mass%, preferably 1 to 30 mass%, particularly preferably 1 to 12 mass% of aerated concrete powder based on the solids content in the fresh concrete mass.

[0062] The fresh concrete mass preferably also contains 0 to 20 mass%, more preferably 0 to 17 mass%, of rock flour, based on the solids content of the fresh concrete mass. The rock flour is preferably limestone flour.

[0063] The fresh concrete mass may also contain at least one admixture known in the art, preferably a superplasticizer and / or a dispersant and / or a sedimentation inhibitor. The superplasticizer is, for example, polycarboxylate ether (PCE). The dispersant is, for example, polyacrylate (PAR) or an acrylic polymer.

[0064] Advantageous compositions or recipes of the fresh concrete mass are given in the following table (values ​​in mass%, based on the total dry mass (=sum of solids) of the fresh concrete mass; admixtures and the foam component are considered as present or available on the market [not their active ingredient content] and additively based on the dry mass): Dry matter solids: preferably [M.-%] [M.-%] Portland cement clinker flour 5 to 45 10 to 35 quicklime 0 to 30 15 to 25 hydrated lime 0 to 20 0 to 10 Ground quartz, preferably sand 25 to 80 30 to 70 Rock flour, e.g. limestone flour 0 to 20 0 to 17 Aerated concrete powder 0 to 60 1 to 30 Return sludge (dry) 0 to 25 2 to 17 Additive to the solids: Aluminum component (active ingredient content) 0 to 0.8 0.03 to 0.8 Foam component, preferably with a density of 40 to 50 kg / m 3< 0 to 45 20 to 42 Foaming agent (active ingredient content) 0 to 3 0.2 to 1.5 Additives (each), e.g. dispersants, flow agents 0 to 3 0 to 1

[0065] The solids contents listed in the table above do not necessarily add up to 100 mass%. Rather, other components may also be included. Consequently, each component and each range disclosed in the table is considered advantageous in its own right. Furthermore, the lower and upper limits of the ranges specified for the individual components can be combined.

[0066] The aluminum component can be aluminum powder, paste, or suspension, as is known per se. The proportions indicated in the table represent the solid or active ingredient content of the respective aluminum component.

[0067] In addition, an aluminum component or, alternatively, a foam component or a foaming agent is always present. Aluminum components, foam components, and foaming agents are thus used alternatively.

[0068] Furthermore, it is preferred if the fresh concrete mass contains cement clinker and at the same time quicklime and / or hydrated lime.

[0069] The return sludge is also preferably pure. It is therefore return sludge made from the material according to the invention.

[0070] As already explained, the aerated or foamed concrete moldings are produced according to the invention in the usual way: Basically, the fresh concrete mass is first produced, which contains Portland cement clinker flour, quicklime and / or hydrated lime as at least one further hydrothermally reacting CaO component different from the Portland cement clinker flour, ground quartz as at least one further hydrothermally reacting SiO 2 component different from the Portland cement clinker flour, preferably waste sludge, at least one blowing agent or foaming agent, and water. According to the invention, the fresh concrete mass is free of sulfate carriers. This means that it does not have any added sulfate carriers. This is because, according to the invention, only ground Portland cement clinker is used as the raw material, which, unlike Portland cement, does not have any added sulfate carriers.

[0071] The fresh concrete mass is poured into a casting mold. If reinforced aerated concrete molds are to be produced, reinforcement can be suspended in the casting mold. Alternatively, the reinforcement can be suspended in the casting mold after the fresh concrete mass has been filled.

[0072] In the case of the production of aerated concrete moldings, the casting compound is allowed to expand.

[0073] In the production of foam concrete molds, the foaming process is eliminated. To produce foam concrete molds, either the fresh mass containing a foaming agent is whipped to form the foam, or the pre-formed foam is mixed in. This preferably occurs before the fresh mass is poured into the mold.

[0074] The casting compound is then allowed to harden into a green porous or foam concrete cake.

[0075] After stiffening, the aerated or foam concrete cake is cut into individual aerated or foam concrete moldings in a conventional manner.

[0076] The cut porous or foam concrete moldings are then hydrothermally cured in the autoclave in a conventional manner under saturated steam conditions.

[0077] For example, autoclaving is carried out with a holding phase of 6 to 12 hours at a temperature of 180 to 190 °C. The start-up and shut-down phases are preferably linear, with no intermediate holding phases. In addition, the start-up and shut-down phases each last, for example, 1.5 to 6 hours. In a very preferred autoclave mode of operation, autoclaving begins with a vacuum phase. After the autoclave has been closed, the air is pumped out of it until a negative pressure of, for example, 0.4 bar is reached. This process takes, for example, 20 - 30 minutes. Steam is then fed into the autoclave and the start-up phase begins. In another preferred mode of operation, the air present in the autoclave is reduced by pressure-free purging with steam. This process takes, for example, 20 - 30 minutes.

[0078] As already explained, it was discovered within the scope of the invention that the green aerated or foam concrete cake can be processed in a conventional manner, i.e. it can be cut using the various cutting methods known in the art. Cutting can be carried out, for example, as follows: As soon as the aerated or foam concrete cake has reached its green strength, the entire casting mold is tilted onto a longitudinal wall of the mold, the so-called hardening base. The other mold walls are then removed together with the mold base. The aerated or foam concrete cake, which is then standing on one of its long sides, is passed through a cutting frame with cutting wires extending horizontally and perpendicular to the longitudinal direction, e.g. with its front side first. Alternatively or additionally, the cutting wires can also be passed through the aerated or foam concrete cake.

[0079] For cross-cutting, for example, the entire aerated or foam concrete cake is pushed vertically upwards through a cutting frame with cutting wires extending horizontally and perpendicular to the longitudinal direction, possibly oscillating, and then lowered again. Alternatively, the cutting frame is lowered and then raised again. For cutting in a vertical direction parallel to the transverse sides, the aerated or foam concrete cake is passed lengthwise through vertically extending knife bars, or these are pulled through the aerated or foam concrete cake. The cut aerated or foam concrete cake is then steam-cured while standing on the hardening floor.

[0080] Of course, the longitudinal and cross cutting can also be done in the reverse order.

[0081] Alternatively, after the cutting process, the aerated or foamed concrete cake can be tilted back or tilted onto a support, preferably a hardening grid, into its original, horizontal position. The cut aerated or foamed concrete cake then rests on the support, preferably the hardening grid, and is preferably hardened there. Before tilting back, the so-called base layer, with which the aerated or foamed concrete cake previously rested on the side wall, is preferably also removed.

[0082] Curing the aerated or foam concrete cake in its horizontal position offers several advantages. In particular, as explained, the so-called bottom layer can be removed, preventing vertical adhesion of the blocks. This eliminates the need for separation, which is usually necessary after curing in an upright position.

[0083] The aerated or foamed concrete cake can also be tilted back from its horizontal position to its vertical, standing position after removing the base layer. It is preferably tilted back onto the side wall and cured there.

[0084] The aerated or foam concrete cake can also be cut using another known cutting method. In this case, the aerated or foam concrete cake is first transferred. To do this, the side walls of the mold are folded back after the aerated or foam concrete cake has stiffened, so that the aerated or foam concrete cake rests flat on the bottom or base of the mold and is no longer supported laterally. The aerated or foam concrete cake is then grasped along its long sides with a gripper, lifted, moved, and placed on a saw table, hardening grid, or other cutting surface.

[0085] The hardening grid comprises cross members, with vertically projecting pins on the cross members and loose longitudinal bars arranged between the pins, on which the underside of the aerated or foam concrete cake rests. Horizontal cutting wires extending transversely across the aerated or foam concrete cake are first stretched above the hardening grid. The cutting wires are then pulled through the aerated or foam concrete cake from bottom to top. The resulting cutting gaps are then preferably closed by pushing the individual aerated or foam concrete molded bodies together. This is necessary to prevent corners from tearing out due to the gaps during the subsequent longitudinal cutting.

[0086] The aerated or foam concrete cake is then cut lengthwise. For this purpose, it is passed through a cutting device comprising a cutting frame with vertically extending cutting wires clamped within it. The cutting wires are preferably driven to oscillate in their longitudinal direction to create a smooth cut surface. The aerated or foam concrete cake is fed to the cutting device on the curing grid. For cutting, the curing grid is lowered and the aerated or foam concrete cake is passed through the cutting device resting only on the longitudinal bars, with the cutting wires being passed through the spaces between the longitudinal bars. After cutting, the cut aerated or foam concrete cake with the longitudinal bars is repositioned on a curing grid and steam-cured in an autoclave together with the curing grid and the longitudinal bars.

[0087] According to another preferred method, the aerated or foam concrete cake ready for cutting is transferred to a cutting table on which the cutting wires for cross-cutting are already resting. These are then moved in an oscillating manner in a conventional manner and pulled upwards through the aerated or foam concrete cake, cutting it crosswise. The individual aerated or foam concrete moldings can then be pushed together using a pusher, closing the resulting cutting gaps. A second cutting frame, this time with vertically tensioned cutting wires, then moves lengthwise through the aerated or foam concrete cake. The cutting wires are fastened at the bottom in movable rods and at the top to a movable frame. The movable rods, in turn, are arranged in longitudinal grooves of the cutting table and can be moved within these. The aerated or foam concrete cake is thus cut lengthwise.The cutting frame can also be equipped with a horizontally tensioned cutting wire or a cutting bar, which serves to separate the upper, curved pouring cap of the aerated or foam concrete cake. Finally, a transport grid is extended from below the table, which picks up the aerated or foam concrete cake and transports it away.

[0088] According to another method, the aerated or foamed concrete cake is placed with the longitudinal bars or directly on cross bars extending horizontally and transversely to the longitudinal bars. The cross bars can be moved up and down vertically, individually. First, the cake is cut transversely in the known manner as described above. For longitudinal cutting, a vertical cutting frame with vertically and / or horizontally extending cutting wires is moved lengthwise through the lying aerated or foamed concrete cake. The cross bars are lowered one after the other so that the cutting frame can be guided between the undersides of the bars or the cake underside and the cross bars.

[0089] Of course, cutting can also be carried out according to WO 2009 / 121635 A1. Furthermore, it can also be carried out according to EP 2 189 262 A1.

[0090] The processes described above show that the stiffened, green aerated or foamed concrete cake produced according to the invention has sufficient strength to be lifted from the bottom of the mold, moved horizontally, and then set down again. This lifting and transfer can be carried out in various ways.

[0091] As already described above, the side walls of the casting mold can be folded away, so that the aerated or foam concrete cake stands freely on the underside of the casting mold and is then gripped, lifted and moved along its long sides with a gripper.

[0092] Alternatively, the side walls of the casting mold can be detached from the mold base and from each other, so that the aerated or foam concrete cake stands on the mold base of the casting mold and is then gripped, lifted and moved over its long sides with a gripper using the long side walls of the casting mold as a kind of holding jaw.

[0093] Alternatively, the interconnected side walls of the mold can be detached from the mold base, forming a box that's open at the top and bottom. The green aerated or foamed concrete cake is then lifted and moved by gripping the interconnected side walls of the mold and using a vacuum suction device placed on top of the box to suck up the aerated or foamed concrete cake.

[0094] The processing of the aerated or foam concrete cake during the transfer, e.g. profiling of the stones or elements with grooves, is also possible in a conventional manner.

[0095] After cutting, the aerated or foam concrete cake can be steam-cured horizontally. Alternatively, the cut aerated or foam concrete cake can be placed upright, e.g., using a tilting table, and cured in an upright position.

[0096] As already explained, the invention not only found that the fresh concrete mass and the aerated or foamed concrete cake are readily processable, but it was also surprising that the aerated and / or foamed concrete blocks produced according to the invention, despite the lack of a sulfate carrier, still exhibit a sufficiently high tobermorite content and thus good strength properties. Thus, surprisingly, the amount and formation of the CSH phases can be controlled even without a sulfate carrier.

[0097] The porous or foam concrete moldings produced according to the invention preferably have a 11Å tobermorite content, based on the dry mass of the porous or foam concrete molding, of 25 to 60 mass%, preferably 30 to 55 mass%, determined by X-ray diffractometry. The 11Å tobermorite content is determined as detailed in the exemplary embodiments.

[0098] Replacing the Portland cement commonly used in aerated concrete production with pure Portland cement clinker flour has the primary advantage that—unlike production with a pure lime formulation—the green strength of the aerated or foamed concrete cake remains the same, and the aerated or foamed concrete cake can be processed using existing equipment. Curing in an autoclave also poses no problems.

[0099] Preferably, the porous or foam concrete moldings produced according to the invention have a compressive strength of 0.1 to 10 N / mm 2 , preferably of 0.15 to 6 N / mm 2 . The compressive strength is determined for porous or foam concrete moldings with a dry bulk density ρ 0 to 150 kg / m 3< according to DIN EN 826:2013 after drying at 40°C to constant mass and for porous or foam concrete bodies with a dry bulk density ρ 0 > 150 kg / m 3< tested on a cube with an edge length of 100 mm according to DIN EN 772-1: 2011-07.

[0100] If the aerated or foam concrete moldings produced according to the invention are preferably unreinforced aerated or foam concrete molding blocks, they preferably have a compressive strength of 1.5 to 10 N / mm 2< , preferably of 1.5 to 6 N / mm 2< , tested on a cube with an edge length of 100 mm in accordance with DIN EN 772-1: 2011-07.

[0101] If the porous or foam concrete molded bodies produced according to the invention are reinforced porous or foam concrete molded components, they preferably have a compressive strength of 1.5 to 10 N / mm 2< , preferably of 1.5 to 6 N / mm 2< , according to DIN EN 679:2005-09.

[0102] If the porous or foam concrete moldings produced according to the invention are porous or foam concrete insulation bodies, in particular porous or foam concrete insulation boards, they preferably have a compressive strength of 0.1 to 0.6 N / mm 2< , preferably of 0.15 to 0.4 N / mm 2< , according to DIN EN 826:2013 after drying at 40°C to constant mass.

[0103] In addition, the porous or foam concrete moldings produced according to the invention preferably have a dry bulk density ρ 0 from 70 to 800 kg / m 3< , preferably from 85 to 600 kg / m 3< , according to DIN EN 772-13: 2000-09 or DIN EN 1602: 2013-05.

[0104] If the porous or foam concrete moldings produced according to the invention are, preferably unreinforced, porous or foam concrete molding blocks, they preferably have a dry bulk density ρ 0 from 220 to 800 kg / m 3< , preferably from 255 to 600 kg / m 3< , according to DIN EN 772-13: 2000-09.

[0105] If the porous or foam concrete moldings produced according to the invention are reinforced porous or foam concrete moldings, they preferably have a dry bulk density ρ 0 from 220 to 800 kg / m 3< , preferably from 255 to 600 kg / m 3< , according to EN 678:1993.

[0106] If the porous or foam concrete moldings produced according to the invention are porous or foam concrete insulation bodies, in particular porous or foam concrete insulation boards, they preferably have a dry bulk density ρ 0 from 70 to 150 kg / m 3< , preferably from 85 to 115 kg / m 3< , according to DIN EN 1602: 2013-05.

[0107] Preferably, the porous or foam concrete moldings produced according to the invention have an A number between 300 and 2600 [-], or between 1000 and 2600 [-], or between1000 and 2200 [-], or between 1000 and 2000 [-], or between 600 and 2000 [-], or most preferably between 1000 and 1800 [-]. All specified ranges are particularly advantageous in their own right.

[0108] The A-number is calculated by dividing the compressive strength by the dry bulk density. It represents the relative compressive strength of the aerated or foam concrete body. The higher the A-number, the better the compressive strength level. The A-number is calculated as follows: A - Zahl − = Druckfestigkeit N / mm 2 / Trockenrohdichte kg / dm 3 2 ⋅ 0 , 016 Ndm 6 / mm 2 kg 2

[0109] Each A number range listed above is particularly advantageous in its own right.

[0110] Furthermore, it was determined within the scope of the invention that, in particular, the hygric properties and the sorption moisture content are improved compared to a pure lime formulation. This can lead, among other things, to a reduction in thermal conductivity (design value of thermal conductivity or λ Design,unit ). The thermal conductivity λ Design,unit is derived from the dry value of the thermal conductivity. λ 10,dry,unit multiplied by the moisture content conversion factor F m . The thermal conductivity λ Design,unit thus takes into account that the thermal conductivity of the material during application is significantly influenced by its adsorption moisture content.

[0111] In particular, the porous or foam concrete moldings produced according to the invention preferably have a thermal conductivity λ10,dry,unit from 0.039 to 0.250 W / (m·K), preferably from 0.039 to 0.220 W / (m·K), in particular from 0.039 to 0.130 W / (m·K), according to DIN EN 12664:2001-05 or DIN EN 12667:2001-05.

[0112] In particular, the aerated or foamed concrete blocks or the aerated or foamed concrete components produced according to the invention preferably have a thermal conductivity λ 10,dry,unit from 0.082 to 0.250 W / (m·K), preferably from 0.085 to 0.160 W / (m·K), in particular from 0.088 to 0.130 W / (m·K), according to DIN EN 12664:2001-05.

[0113] In particular, the porous or foam concrete insulation bodies produced according to the invention preferably have a thermal conductivity λ 10,dry,unit from 0.039 to 0.050 W / (m·K), preferably from 0.039 to 0.045 W / (m·K), in particular from 0.039 to 0.042 W / (m·K), according to DIN EN 12667:2001-05.

[0114] Furthermore, the porous or foam concrete moldings produced according to the invention preferably have a total shrinkage ε cs,tot according to DIN EN 680:2006-03 from 0.2 to 0.8 mm / m, preferably from 0.2 to 0.4 mm / m.

[0115] And the adsorption moisture content u m,80 of the porous or foam concrete moldings produced according to the invention is preferably 2 to 8 mass%, preferably 2.5 to 5 mass%, particularly preferably 2.5 to 4.5 mass%, according to DIN EN ISO 12571: 2013-12.

[0116] In summary, it is surprisingly easy to produce porous or foam concrete bodies with good mechanical and hygric properties from fresh concrete masses that contain Portland cement clinker flour but no added sulfate carrier.

[0117] In the following, the invention will be illustrated by means of some embodiments. Examples of implementation:

[0118] In the examples, aerated concrete molds were produced using different formulations. The aerated concrete molds were always produced as follows: The test samples were mixed with a dissolver mixer at 550 rpm (disk diameter 12 cm) in a 20-liter mixing vessel as follows: 1. Place water and, if necessary, residual sludge and, if necessary, additives in the mixing vessel 2. Add quartz powder, if necessary, limestone powder, if necessary, aerated concrete powder Mixing time 30 seconds 3. Add the binders, mixing time 30 seconds 4. Add aluminum in suspension (100 ml), mixing time 20 seconds 5. Cast

[0119] The test samples were demolded after 3 - 5 hours, transferred to the hardening floor and then autoclaved.

[0120] Autoclaving began with a 30-minute vacuum phase, reaching a pressure of 0.4 bar abs. The pressure was then increased linearly to 12 bar abs over 1.5 hours, held for 7 hours, and then reduced to ambient pressure, also linearly, over 1.5 hours.

[0121] The following raw materials were used to conduct the tests: Table 1: Raw materials used Material / Description note Manufacturer Crystal quartz flour Dorsilit 16900 (1st-5th test series) Specific surface area according to Blaine 6,000 cm 2 < / g Gebrüder Dorfner GmbH Crystal quartz flour KR500 (6th test series) Specific surface area according to Blaine 10,000 cm 2 < / g Kreutz Mahlwerke GmbH White fine lime WFK 11 / 6 Lime slaking test t 60 = 11 min Fels Werke GmbH Portland cement CEM l 42.5 R(ft) Specific surface area according to Blaine 5000 cm 2 < / g Dornburger Cement Anhydrite Microanhydrite B Technical anhydrite Casea GmbH Portland cement clinker flour Specific surface area according to Blaine 5210 cm 2 < / g Buzzi Dyckerhoff Limestone flour Specific surface area according to Blaine 3,500 cm 2 < / g Lafarge Aerated concrete powder, sulfate-free < 1.0 mm, bulk density 473 g / l Xella T&F GmbH Aluminum powder OT9 / 10 100% aluminum active ingredient content Lerberghe, AVL Aluminum paste N905 / 75 75% aluminum active ingredient content Eckart GmbH Table 2: Properties of clinker flour SiO 2 [1]< M.-% 20,24 TiO 2 [1]< M.-% 0,26 Al 2 O 3 [1]< M.-% 5,29 Fe 2 O 3 [1]< M.-% 1,94 Mn 3 O 4 [1]< M.-% 0,11 MgO [1]< M.-% 0,91 CaO [1]< M.-% 64,57 Na 2 O [1]< M.-% < 0,05 K 2 O [1]< M.-% 0,90 P 2 O 5 [1]< M.-% 0,14 Loss on ignition M.-% 3,08 H 2 O (calculated) M.-% 0,71 CO2 [2]< M.-% 2,38 SO3 [2]< M.-% 1,38 Specific surface according to BLAINE [3]< cm 2 < / g 5210 [1]< Determined by X-ray fluorescence analysis using an AXIOS PW 4400 from PANalytical BV [2]< Determined by infrared spectrometry using an Eltra CS-2000 from Eltra GmbH [3]< Determined according to DIN EN 196-6:2017-05 using a ToniPERM 6565 from Toni Technik Baustoffprüfsysteme GmbH Table 3: Additives used Manufacturer Sales Product name Description Area of ​​application BK Giulini Calgon N Sodium polyphosphate Wetting and dispersing additive BASF Dispex AA 4140 Sodium acrylate polymer Wetting and dispersing additive CIMACHEM PBTC 2-Phosphono-1,2,4-butanetricarboxylic acid Chelating agents BASF SKY 519 Polycarboxylate ethers Concrete admixtures BASF Master X-Seed 120 Crystallization nuclei (seeding substance) with polycarboxylate ether Concrete admixtures Nabaltec AG Apyral aluminum hydroxide Functional additive Test series 1:

[0122] In the first series of tests, the C / S ratio of cement clinker-containing formulations according to the invention was varied. For this purpose, the proportions of quartz flour, fine white lime, and Portland cement clinker flour were varied: Table 4: Compositions of the recipes of the 1st test series Attempt 1A 1B 1C 1D 1E Return sludge Total weight of solids [g] 5000 5000 5000 5000 5000 7000 [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] quartz flour 48,0 46,0 41,0 38,0 34,0 46,0 Clinker flour 16,0 17,0 19,5 21,0 23,0 22,0 White fine lime 16,0 17,0 19,5 21,0 23,0 22,0 Limestone flour 10,0 10,0 10,0 10,0 10,0 10,0 Return sludge (tr.) 10,0 10,0 10,0 10,0 10,0 0,0 Total solids 100 100 100 100 100 100 Aluminiumpulver 1)< 0,14 0,14 0,14 0,14 0,14 0,20 W / F [-] 0,65 0,65 0,65 0,65 0,65 0,65 Casting temperature [°C] 40+ / -1 40+ / -1 40+ / -1 40+ / -1 40+ / -1 40+ / -1 C / S ratio 0,46 0,51 0,66 0,78 0,95 0,67 1)< Quantity based on total solids

[0123] The return sludge was prepared the day before and continuously stirred. The material was mixed and poured as usual, the cake was expanded, and then deporized with water using the same mixer and re-sludged. The sludge was then continuously stirred. Before use in the casting, a return sludge density of 1.35 kg / dm³ was adjusted by adding water. The return sludge temperature at the time of processing was 25 + / - 1 °C.

[0124] The dry bulk density according to DIN EN 772-13: 2000-09, the compressive strength according to DIN EN 772-1: 2011-07, the A-number, the adsorption moisture u m,80 according to DIN EN ISO 12571: 2013-12 and the shrinkage εcs,tot was determined according to DIN EN 680:2006-03. In addition, the mineralogical phase composition was determined using X-ray diffraction. This was carried out as follows: Drilling dust was removed from the aerated concrete moldings using a commercially available pillar drill (HSS drill, diameter 24 mm). These powder samples were first dried for 24 hours at 40°C in a drying cabinet. For subsequent wet grinding, 10 wt.% internal standard zincite (ZnO from JT Baker Avantor Performance Materials, Inc.) was added to each sample; this corresponds to 1.8 g of substance and 0.2 g of ZnO each. Wet grinding in the micron mill (McCrone micronizing mill) was carried out in 10 ml of 2-propanol for 4.5 minutes in PVC grinding bowls with ZrO2 grinding cylinders. The ground material was rinsed, rinsed four times with 5 ml of 2-propanol (AnalaR NORMA-PUR, VWR) each time, filtered over hard filter paper (84 g / m 2<, No. 1291; Sartorius) under a fume hood for 24 h and dried at room temperature (20°C).The powder, brushed off the filter paper and homogenized for 2 minutes in an agate mortar, was compressed into a diffractometer powder tablet (backloading method). A powder tablet was prepared and measured from each sample taken.

[0125] The samples were measured on a Panalytical MPD Pro diffractometer. Qualitative phase determination was performed using Panalytical HighScorePlus software. The measurement conditions and further information are listed in Table 5. Table 5: Measurement conditions and further information Goniometer Unit Panalytical MPD Pro Angular range °2 Theta 5-80 Step size °2 Theta 0,017 Measuring time per step s 45 Anode material copper Current I mA 40 Voltage U kV 45 Automatic aperture irradiated sample length mm 10 Detector (semiconductor technology) X'Celerator (128 channels) qualitative evaluation: HighScore Plus 3.0e from January 30, 2012 Database basis PDF2 from 2004 HighScore Plus ICSD

[0126] Quantitative determination was performed using the Rietveld method. Bruker AXS Topas (version 5) was used as the analysis software. To determine the amorphous phase fraction, 10 wt.% zinc oxide (see above) was added to the sample as an internal standard and subtracted accordingly during the analysis. The remaining phases, including X-ray amorphous phases, were normalized to 100%.

[0127] The following structures from the ICSD database (Inorganic Crystal Structure Database, as of 2016) were used to evaluate the quantitative phase composition: 11Å Tobermorite (#92943) Quartz (#34636) Anhydrite (#15876) Katoite (#49772) Calcite (#18165) Zincite (#65120)

[0128] The results of the measurements of the mechanical and hygric properties of the first series of tests are shown in Table 6. Table 7 shows the mineralogical phase compositions of the tests of the first series of tests. Table 6: Results of the measurements of the mechanical and hygric properties of the 1st test series Attempt C / S Dry bulk density Cube compressive strength A-number Adsorption humidity shrinkage (Constant mass 50°C) (Constant mass 50°C) u m,80 ε cs,everything [-] [kg / dm 3 ] [N / mm 2 ] [-] [M.-%] [mm / m] 1A 0,46 0,418 2,75 984 3,0 0,66 1B 0,51 0,425 3,91 1353 2,4 0,46 1C 0,66 0,443 5,27 1678 2,2 0,33 1D 0,78 0,442 5,15 1648 2,2 0,36 1E 0,95 0,461 4,38 1288 3,5 0,48 Table 7: Results of the measurements of the mineralogical phase compositions of the 1st test series Sample number Amorphous 11Å-Tobermorite quartz Anhvdrit Katoit Calcite [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] 1A 36 29 23 0 2 10 1B 30 39 19 0 2 10 1C 27 51 11 0 2 9 1D 28 53 8 0 2 9 1E 40 37 7 0 4 12

[0129] In Fig. 1 In addition, the determined A numbers and the amorphous phase content are plotted against the C / S ratio.

[0130] The first series of tests already demonstrates that all formulations are easy to process and that the resulting aerated concrete molded bodies exhibit good mechanical strength properties. The optimum binder for the quartz powder fineness used is a C / S ratio of approximately 0.66, which is also typical for conventional cement formulations with sulfate carriers.

[0131] For higher quartz powder finenesses, the strength optimum is at higher C / S ratios, and at lower finenesses, even below 0.46. The invention works at any conventional C / S ratio, e.g., even at 0.38 or 1.0. 2nd series of experiments:

[0132] In a second series of tests, the quartz powder was partially replaced by aluminum hydroxide (product name Apyral from Nabaltec): Table 8: Compositions of the recipes of the 2nd test series Attempt 2A 2B 2C 2D 2E Total weight of solids [g] 5000 5000 5000 5000 5000 [%] [%] [%] [%] [%] quartz flour 45,6 45,3 44,9 43,3 42,3 Clinker flour 21,7 21,8 21,9 22,2 23,0 White fine lime 21,7 21,8 21,9 22,2 23,0 Limestone flour 11,0 11,1 11,3 11,3 11,7 Total solids 100 100 100 100 100 Aluminum hydroxide 1)< 0,0 0,5 1,1 2,4 6,0 Alupaste 1)< 0,16 0,16 0,16 0,16 0,17 W / F [-] 0,7 0,7 0,7 0,7 0,7 Casting temperature [°C] 35+ / -1 35+ / -1 35+ / -1 35+ / -1 35+ / -1 1)< Quantity based on total solids Table 9: Results of the measurements of the mechanical and hygric properties of the 2nd test series Attempt aluminum hydroxide Dry bulk density Cube compressive strength A-number Adsorption moisture content Total shrinkage (Constant mass 50°C) (Constant mass 50°C) u m,80 ε cs,everything [M.-%] based on solids [kg / dm 3 ] [N / mm 2 ] [-] [M.-%] [mm / m] 2A 0,0 0,402 4,14 1601 2,7 0,39 2B 0,5 0,392 4,21 1712 2,6 0,38 2C 1,1 0,386 3,64 1527 2,6 0,34 2D 2,4 0,399 4,13 1621 2,6 0,36 2E 6,0 0,403 3,92 1509 2,4 0,34 Table 10: Results of the measurements of the mineralogical phase compositions of the 2nd test series Sample number Amorphous 11Å-Tobermorite quartz Anhydrite Katoit Calcite [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] 2A 27 53 9 0 0 11 2B 28 52 9 0 0 11 2C 29 51 9 0 0 11 2D 25 49 10 0 4 12 2E 23 44 12 0 9 12

[0133] It was found that a small addition of aluminum hydroxide has a positive effect on the strength level of the aerated concrete moldings. However, the tobermorite content decreases with increasing aluminum hydroxide content. 3rd series of experiments:

[0134] In the third series of tests, three different construction chemical additives were used, namely the crystallization accelerator X-Seed 120, the dispersing additive PBTC and the superplasticizer Sky 519. The concentrations of the construction chemical additives correspond to the concentrations usually used in conventional lime-cement formulations. rations: Table 11: Compositions of the recipes of the 3rd test series 3A 3B 3C 3D Total weight Solids [g] 5000 5000 5000 5000 [%] [%] [%] [%] quartz flour 45,6 45,6 45,6 45,6 Clinker flour 21,7 21,7 21,7 21,7 White fine lime 21,7 21,7 21,7 21,7 Limestone flour 11,0 11,0 11,0 11,0 Total solids 100,0 100,0 100,0 100,0 X-seed 120 (sus.) 1)< 0,00 2,00 0,00 0,00 SKY 519 (sus.) 1)< 0,00 0,00 0,10 0,00 PBTC (fl.) 1)< 0,00 0,00 0,00 0,14 Aluminum paste 1)< 0,22 0,22 0,22 0,22 W / F [-] 0,70 0,70 0,70 0,70 Casting temperature [°C] 35+ / -1 35+ / -1 35+ / -1 35+ / -1 1)< Quantity based on total solids Table 12: Results of the measurements of the mechanical and hygric properties of the 3rd test series Attempt Additive content Dry bulk density Cube compressive strength A-number Adsorption moisture content Total shrinkage (Constant mass 50°C) (Constant mass 50°C) u m,80 ε cs,everything [% / FS] [kg / dm 3 ] [N / mm 2 ] [-] [M.-%] [mm / m] 3A 0,00 0,359 3,44 1668 2,3 0,38 3B 2.00 (X-SEED) 0,369 3,80 1744 2,4 0,38 3C 0.10 (SKY519) 0,360 3,63 1751 2,3 0,36 3D 0.14 (PBTC) 0,335 2,92 1626 2,5 0,41 Table 13: Results of the measurements of the mineralogical phase compositions of the 3rd test series Sample number Amorphous 11Å-Tobermorite quartz Anhydrite Katoit Calcite [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] 3A 28 52 10 0 0 10 3B 26 55 10 0 0 10 3C 28 53 10 0 0 10 3D 29 52 10 0 0 10

[0135] It has been shown that the additives, with the exception of PBTC, have a positive influence on the strength level. Furthermore, the hygric properties are improved or remain at the same level. Phase analysis also shows that Sky 519 and X-Seed 120 tend to increase the tobermorite content and decrease the amorphous phase content. 4th series of experiments:

[0136] In the fourth series of tests, a classic cement-anhydrite formulation (CAH), a sulfate-reduced cement formulation (SRC), in which the sulfate carrier comes exclusively from the cement, and a sulfate-carrier-free formulation according to the invention (KLINK) were compared.

[0137] The three different binder batches were each mixed with two different dispersants (Calgon N and Dispex AA 4041) and a superplasticizer (Sky 519): Table 14: Compositions of the recipes of the 4th test series CAH series Attempt 4A 4B 4C 4D Total weight of solids [g] 3500 3500 3500 3500 [%] [%] [%] [%] quartz flour 44,0 44,0 44,0 44,0 Portland cement 21,0 21,0 21,0 21,0 Clinker flour 0,0 0,0 0,0 0,0 White fine lime 20,9 20,9 20,9 20,9 Anhydrite 3,1 3,1 3,1 3,1 Limestone flour 11,0 11,0 11,0 11,0 Total solids 100,0 100,0 100,0 100,0 Calgon (fest) 1)< 0,0 0,0 0,0 0,4 Dispex (in) 1)< 0,0 0,0 0,4 0,0 Sky 519 (fl.) 1)< 0,0 0,4 0,0 0,0 Aluminiumpulver 1)< 0,19 0,19 0,19 0,19 W / F [-] 0,70 0,70 0,70 0,70 Casting temperature [°C] 40+ / -1 40+ / -1 40+ / -1 40+ / -1 1)< Quantity based on total solids SRC series Attempt 4E 4F 4G 4H Total weight of solids [g] 3500 3500 3500 3500 [%] [%] [%] [%] quartz flour 45,6 45,6 45,6 45,6 Portland cement 21,7 21,7 21,7 21,7 Clinker flour 0,0 0,0 0,0 0,0 White fine lime 21,7 21,7 21,7 21,7 Anhydrite 0,0 0,0 0,0 0,0 Limestone flour 11,0 11,0 11,0 11,0 Total solids 100,0 100,0 100,0 100,0 Calgon (solid) 1) 0,0 0,0 0,0 0,4 Dispex (fl) 1) 0,0 0,0 0,4 0,0 Sky 519 (fl.) 1) 0,0 0,4 0,0 0,0 Aluminum powder 1) 0,19 0,19 0,19 0,19 W / F [-] 0,70 0,70 0,70 0,70 Casting temperature [°C] 40+ / -1 40+ / -1 40+ / -1 40+ / -1 1)< Quantity based on total solids KLINK series Attempt 4I 4J 4K 4L Total weight of solids [g] 3500 3500 3500 3500 [%] [%] [%] [%] quartz flour 45,6 45,6 45,6 45,6 Portland cement 0,0 0,0 0,0 0,0 Clinker flour 21,7 21,7 21,7 21,7 White fine lime 21,7 21,7 21,7 21,7 Anhydrite 0,0 0,0 0,0 0,0 Limestone flour 11,0 11,0 11,0 11,0 Total solids 100,0 100,0 100,0 100,0 Calgon (solid) 1)< 0,0 0,0 0,0 0,4 Dispex (in) 1)< 0,0 0,0 0,4 0,0 Sky 519 (fl.) 1)< 0,0 0,4 0,0 0,0 Aluminum powder 1)< 0,19 0,19 0,19 0,19 W / F [-] 0,70 0,70 0,70 0,70 Casting temperature [°C] 40+ / -1 40+ / -1 40+ / -1 40+ / -1 1)< Quantity based on total solids

[0138] To test the workability of the fresh concrete masses, the slump was determined as described above.

[0139] The results of the slump measurements are shown in Fig. 2 to recognize. In Fig. 3 the determined A numbers are listed.

[0140] Table 15 shows the results of the measurements of the mechanical, thermal, and hygric properties of the fourth test series. Table 16 shows the results of the measurements of the mineralogical phase compositions of the fourth test series: Table 15: Results of the measurements of the mechanical, thermal and hygric properties of the 4th test series Attempt Recipe Dry bulk density Cube compressive strength A-number Thermal conductivity Adsorption moisture content (Constant mass 50°C) (Constant mass 50°C) λ 10,dry, unit u m,80 [kg / dm 3 ] [N / mm 2 ] [-] W / (m·K) [M.-%] 4A CAH (REF) 0,375 4,2 1867 nb 3,1 4B CAH + PCE 0,558 6,53 1311 nb 3,1 4C CAH + DIS 0,359 3,41 1654 0,0816 4,1 4D CAH + CAL 0,344 3,11 1643 0,0797 3,4 4E SRC (REF) 0,327 3,07 1794 0,0748 2,9 4F SRC + PCE 0,437 4,52 1479 nb 3,1 4G SRC + DIS 0,321 1,24 752 0,0688 4,6 4H SRC + CAL 0,326 2,24 1317 0,0729 3,7 4I KLINK (REF) 0,326 2,81 1653 0,0743 3,1 4J KLINK + PCE 0,315 2,24 1411 0,0742 3,0 4K KLINK + DIS 0,341 2,53 1360 0,0749 3,8 4L KLINK + CAL 0,347 2,13 1106 0,0716 4,0 CAH: Cement-anhydrite formulation; SRC: Sulfate-reduced cement formulation; KLINK: Clinker flour formulation; PCE: Sky 519; DIS: Dispex AA 4140; CAL: Calgon N; REF: Reference without additives Table 16: Results of the measurements of the mineralogical phase compositions of the 4th test series Sample number Amorphous 11Å-Tobermorite quartz Anhvdrit Katoit Calcite [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] 4A 28 51 9 3 0 9 4B 27 51 10 2 0 10 4C 32 43 12 2 0 11 4D 34 45 9 2 0 10 4E 29 53 9 0 0 9 4F 28 53 10 0 0 9 4G 39 30 14 0 3 14 4H 34 46 9 0 0 11 4I 28 52 10 0 0 10 4J 27 51 9 0 2 11 4K 32 43 11 0 2 12 4L 32 44 9 0 2 13

[0141] Out of Fig. 2 It can be seen that the sulfate carrier-free formulation (KLINK) according to the invention without additives exhibits a significantly lower slump than the two sulfate carrier-containing formulations. This was to be expected (keyword: spoon binder).

[0142] Surprisingly, the addition of the superplasticizer (Sky 519) did not increase the slump of the sulfate carrier-free formulation (KLINK+PCE) compared to the sulfate carrier-free reference formulation (KLINK (REF)). However, the other additives resulted in a significant increase in the slump of the sulfate carrier-free formulations according to the invention (KLINK+CAL). 5th series of experiments:

[0143] Table 17: Compositions of the recipes of the 5th test series Attempt 5A 5B 5C 5D Total weight of solids [g] 5400 5400 5400 5400 [%] [%] [%] [%] quartz flour 49,0 50,6 50,6 50,6 Portland cement 18,6 19,2 0,0 0,0 Clinker flour 0,0 0,0 19,2 19,2 White fine lime 19,6 20,2 20,2 20,2 Anhydrite 2,8 0,0 0,0 0,0 Limestone flour 10,0 10,0 10,0 10,0 Total solids 100,0 100,0 100,0 100,0 X-Seed 120 (fl.) 1)< 0,00 0,00 1,90 0,00 Aluminiumpulver 1)< 0,12 0,12 0,12 0,15 W / F [-] 0,7 0,7 0,7 0,7 Casting temperature [°C] 40+ / 1 40+ / 1 40+ / 1 40+ / 1 Lever hardness 3.5h 520 440 420 280 Lever hardness 4.5h nb nb 580 500 1)< Quantity based on total solids

[0144] In the fifth series of tests, it was shown that similar values ​​for green hardness and green strength were achieved with the formulations according to the invention as with the conventional lime-cement formulations.

[0145] A standard formulation (5A) with 18.6 wt% CEM I and 2.8 wt% sulfate carrier showed a strength of 520 scale divisions (Skt) after 210 minutes, measured using a CT-421 pocket penetrometer and a 20 mm diameter cylindrical test head. Without the addition of sulfate carrier (5B), a value of 440 Skt was achieved. The inventive formulation (5D) without the addition of construction chemical additives achieved a strength of 280 Skt in the same time; with the addition of 6.49 X-Seed (5C), the strength was 420 Skt. After extending the curing time by 60 minutes, (5D) achieved a strength of 500 Skt and (5C) 580 Skt.

[0146] The formulations according to the invention thus achieve the necessary strength for transferring the aerated concrete block from the mold base to the cutting machine or cutting grid. The formulations according to the invention can therefore be processed on all systems commonly used in aerated concrete plants. The formulations according to the invention can advantageously be processed on systems using the so-called tilting technique, but they are not limited to this. The autoclaving of the aerated or foamed concrete molded bodies can be carried out using the procedure customary for the respective plant. No changes or adjustments to the autoclaving process are necessary. 6th series of experiments:

[0147] In the sixth series of tests, recipes were processed with the addition of aerated concrete powder and sludge, Table 18: Compositions of the recipes of the 6th test series Attempt 6A 6B Return sludge Total weight of solids [g] 3600 3600 800 [%] [%] [%] quartz flour 34,9 30,8 40,2 Clinker flour 33,2 29,6 35,8 White fine lime 19,9 17,6 24,0 Limestone flour 0,0 4,0 0,0 Aerated concrete powder (dry) 10,0 8,0 0,0 Return sludge (tr.) 2,0 10,0 0 Total solids 100,0 100,0 100,0 Aluminum paste 1)< 0,21 0,21 0,21 W / F [-] 1,1 1,1 1,1 Casting temperature [°C] 39+ / -1 39+ / -1 39+ / -1 1)< Quantity based on total solids

[0148] The return sludge was prepared on the day of casting as described in Test Series 1 and continuously stirred. Before use in the casting process, a return sludge density of 1.20 kg / dm 3 was added. The return sludge temperature at the time of processing was 25 + / - 1 °C.

[0149] Autoclaving began with a 30-minute vacuum phase, during which a pressure of 0.4 bar abs was reached. The pressure was then increased linearly to 12 bar abs over 6 hours, held for 6 hours, and then reduced, also linearly, to ambient pressure over 6 hours.

[0150] Table 19 shows the results of the measurements of the mechanical properties of the sixth series of tests, Table 20 the results of the measurements of the mineralogical phase compositions: Table 19: Results of the measurements of the mechanical properties of the 6th test series Attempt C / S Dry bulk density Cube compressive strength (constant mass 50°C) A-number (constant mass 50°C) [-] [kg / dm 3 ] [N / mm 2 ] [-] 6A 0,92 0,275 2,67 2207 6B 0,92 0,266 2,42 2138 Table 20: Results of the measurements of the mineralogical phase compositions of the 6th test series Sample number Amorphous 11Å-Tobermorite quartz Anhydrite Katoit Calcite [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] [M.-%] 6A 38 59 1 0 0 2 6B 37 53 1 0 3 6

[0151] The results of the sixth series of tests demonstrate that the use of aerated concrete powder is possible without any problems with the formulations according to the invention and that A-numbers above 2200 can be achieved.

Claims

1. Method for the production of hydrothermally hardened aerated or foamed concrete molded bodies, comprising the following method steps: a) Preparing a fresh concrete mass containing Portland cement clinker meal, quicklime and / or hydrated lime, ground quartz, preferably return slurry, water and at least one expanding agent or prefabricated foam or a foaming agent, b) If applicable, foaming the fresh concrete mass containing the foaming agent by stirring, c) Pouring the ready-to-pour fresh concrete mass into a casting mold, d) If necessary, allowing the fresh concrete mass to expand, e) Allowing the fresh concrete mass to stiffen to form an aerated or foamed concrete cake, f) Cutting the aerated or foamed concrete cake into individual aerated or foamed concrete molded bodies, g) Hardening the aerated or foamed concrete molded bodies in an autoclave, characterized in that the fresh concrete mass does not contain a sulfate carrier as a setting regulator and the fresh concrete mass preferably does not contain magnesium carbonate as an additive.

2. Method according to claim 1, characterized in that a fresh concrete mass is prepared which comprises a Portland cement clinker meal content of 5 to 45 ma.-%, preferably 10 to 35 ma.-%, particularly preferably 10 to 25 ma.-%, relative to the solids content in the fresh concrete mass.

3. Method according to claim 1 or 2, characterized in that a fresh concrete mass with a water / solids ratio of 0.45 to 1.5, preferably 0.55 to 1.0, particularly preferably 0.6 to 1.0, is prepared.

4. Method according to any one of the preceding claims, characterized in that quartz makes up the majority of SiO2 in the fresh concrete mass.

5. Method according to any one of the preceding claims, characterized in that a fresh concrete mass is prepared, which comprises a) a quartz content of 25 to 80 ma.-%, preferably 30 to 70 ma.-%, particularly preferably 30 to 45 ma.-%, relative to the solids content in the fresh concrete mass, and / or b) a quicklime content of 5 to 25 ma.-%, preferably 10 to 25 ma.-%, particularly preferably 15 to 25 ma.-%, relative to the solids content in the fresh concrete mass, and / or c) a return slurry content (dry mass) of 2 to 35 ma.-%, preferably 2 to 25 ma.-%, preferably 2 to 20 ma.-%, particularly preferably 2 to 17 ma.-%, most preferably 10 to 15 ma.-%, relative to the solids content in the fresh concrete mass, and / or d) an aerated concrete meal content of 0 to 60 ma.-%, preferably 1 to 30 ma.-%, particularly preferably 1 to 12 ma.-%, relative to the solids content in the fresh concrete mass, and / or e) a content of inert rock flour, preferably limestone powder, of 0 to 20 ma.-%, preferably 0 to 17 ma.-%, relative to the solids content in the fresh concrete mass.

6. Method according to any one of the preceding claims, characterized in that a fresh concrete mass containing an expanding agent or foaming agent is prepared, which comprises a slump in accordance with DIN EN 12350-5: 2009-08 of 20 to 45 cm, preferably 25 to 40 cm, before foaming or expanding.

7. A method according to any one of the preceding claims, characterized in that a fresh concrete mass is produced which contains a crystallization accelerator, preferably in an amount of 0.5 to 5 ma.-%, preferably 1 to 3 ma.-%, relative to the solids content in the fresh concrete mass.

8. Method according to any one of the preceding claims, characterized in that the aerated or foamed concrete cake is tilted onto one of its longitudinal sides after stiffening and before cutting, the aerated or foamed concrete cake preferably being tilted onto a longitudinal mold wall of the casting mold and the other mold walls of the casting mold then being removed, wherein preferably a) the cut aerated or foamed concrete cake is hardened standing on the longitudinal mold wall, or b) the cut aerated or foamed concrete cake is tilted back or through into a lying position after cutting and is preferably hardened in the lying position, a bottom layer of the aerated or foamed concrete cake preferably being removed after tilting back or through, or c) the cut aerated or foamed concrete cake is tilted back or through into a lying position after cutting, a bottom layer of the aerated or foamed concrete cake is removed after tilting back or through, and the aerated or foamed concrete cake is then tilted back into a standing position and preferably hardened in the standing position.

9. Method according to any one of claims 1 to 7, characterized in that after stiffening of the aerated or foamed concrete cake, the green aerated or foamed concrete cake is lifted and displaced, in particular deposited on the respective cutting base, wherein preferably a) after stiffening, side walls of the casting mold are folded away so that the aerated or foamed concrete cake stands on a mold underside of the casting mold and then the green aerated or foamed concrete cake is gripped, lifted and displaced, preferably via its longitudinal sides, with a gripper, or b) after stiffening of the aerated or foamed concrete cake, the side walls of the casting mold are released so that the aerated or foamed concrete cake stands on the mold underside of the casting mold and then the green aerated or foamed concrete cake is gripped, lifted and displaced with a gripper via its longitudinal sides using the side walls as gripper jaws, or c) after stiffening of the aerated or foamed concrete cake, the interconnected side walls of the casting mold are released from the mold underside, so that the aerated or foamed concrete cake stands on the mold underside of the casting mold and a box open at the top and bottom is formed and then the green aerated or foamed concrete cake is lifted and displaced by gripping the four interconnected side walls of the casting mold and with a vacuum suction cup, which is placed on the top of the box and sucks the aerated or foamed concrete cake.

10. Method according to any one of the preceding claims, characterized in that a) aerated or foamed concrete molded bodies are produced which comprise a sulfate concentration ≤ 100 mg / I, preferably ≤ 50 mg / l, of sulfate in the eluate according to DIN 12457-4:2003-01 (DEV S 4) upon leaching, and / or b) aerated or foamed concrete molded bodies with a content of 11Å tobermorite, relative to the dry mass of the respective aerated or foamed concrete molded body, of 25 to 60 ma.-%, preferably 30 to 55 ma.-%, determined by X-ray diffraction, and / or c) aerated or foamed concrete molded bodies with a thermal conductivity λ10,dry,unit of 0.039 to 0.250 W / (m·K), preferably from 0.039 to 0.220 W / (m·K), in particular from 0.039 to 0.130 W / (m·K), in accordance with DIN EN 12664: 2001-05 and DIN EN 12667:2001-05, and / or d) aerated or foamed concrete molded bodies with a total value of the drying shrinkage εcs,tot according to DIN EN 680:2006-03 of 0.2 to 0.8 mm / m, preferably 0.2 to 0.4 mm / m, and / or e) aerated or foamed concrete molded bodies with a dry density ρ0 of 70 to 800 kg / m3, preferably 85 to 600 kg / m3, in accordance with DIN EN 772-13: 2000-09, and / or f) aerated or foamed concrete molded bodies with an adsorption moisture content um,80 of 2 to 8 ma.-%, preferably 3 to 5 ma.-%, particularly preferably 2.5 to 4.5 ma.-% according to DIN EN ISO 12571: 2013-12, and / or g) aerated or foamed concrete molded bodies with a compressive strength of 0.1 to 10 N / mm2, preferably 0.15 to 6 N / mm2, are produced.

11. A method according to any one of the preceding claims, characterized in that aerated or foamed concrete molded bodies with an A-number between 300 and 2600 [-], or between 1000 and 2600 [-], or between 1000 and 2200 [-], or between 1000 and 2000 [-], or between 600 and 2000 [-], or preferably between 1000 and 1800 [-], are produced, where the A-number is calculated as follows: A − number − = compressive strength N / mm 2 / dry density kg / dm 3 2 ⋅ 0.016 Ndm 6 / mm 2 kg 2 12. A method according to any one of the preceding claims, characterized in that aerated or foamed concrete bricks a) with a thermal conductivity λ10,dry,unit of 0.082 to 0.250 W / (m·K), preferably from 0.085 to 0.160 W / (m·K), in particular from 0.088 to 0.130 W / (m·K), in accordance with DIN EN 12664: 2001-05, and / or b) with a dry density ρ0 of 220 to 800 kg / m3, preferably 255 to 600 kg / m3, in accordance with DIN EN 772-13: 2000-09, and / or c) with a compressive strength of 1.5 to 10 N / mm2, preferably 1.5 to 6 N / mm2, in accordance with DIN EN 772-1: 2011-07, are produced.

13. Method according to any one of claims 1 to 11, characterized in that reinforced aerated or foamed concrete components a) with a dry densityρ0 of 220 to 800 kg / m3, preferably 255 to 600 kg / m3, in accordance with DIN EN 678:1993, and / or b) with a compressive strength of 1.5 to 10 N / mm2, preferably 1.5 to 6 N / mm2, in accordance with DIN EN 679:2005-09, are produced.

14. Method according to any one of claims 1 to 11, characterized in that a) aerated or foamed concrete insulating bodies with a thermal conductivity λ10,dry,unit of 0.039 to 0.050 W / (m·K), preferably from 0.039 to 0.045 W / (m·K), in particular from 0.039 to 0.042 W / (m·K), in accordance with DIN EN 12667:2001-05, and / or b) aerated or foamed concrete insulating bodies, in particular aerated or foamed concrete insulating boards, with a dry density ρ0 of 70 to 150 kg / m3, preferably 85 to 115 kg / m3, in accordance with DIN EN 1602: 2013-05, and / or c) aerated or foamed concrete insulating bodies, in particular aerated or foamed concrete insulating boards, with a compressive strength of 0.1 to 0.6 N / mm2, preferably 0.15 to 0.4 N / mm2, in accordance with DIN EN 826:2013, and conditioning at 40°C to constant mass, are produced.