CZ2017187A3 - Concrete, a dry mix for the preparation of concrete, and a method of preparing this concrete - Google Patents

Abstract

Fresh concrete is described which contains 135 to 250 kg of water, 135 to 400 kg of cement, 28 to 52 kg of quartz drift and 1000 to 2000 kg of aggregate with an upper fraction of up to 16 mm and up to 8 mm, with 70 to 100% this aggregate is made up of brick, ceramic or mixed recycled waste from inert construction demolition waste with a recycle fraction of 0 to 16 mm, or 0 to 8 mm and / or concrete recycled with a recycle fraction of 0 to 16 mm, respectively. 1 to 16 mm, or 0 to 8 mm, respectively. 1 to 8 mm. Any remaining aggregate - max. 30% by weight - is then composed of natural aggregate with an upper fraction of up to 16 mm, respectively. up to 8 mm. Another 0 to 30 wt. the aggregate may comprise at least one known refining agent which improves the thermal and / or sound and / or fire performance of the concrete and is commonly used in standard concrete. Furthermore, it also relates to a dry composition for the preparation of such concrete, as well as to a concrete product or prefabricated component made of such concrete. In addition, it also relates to a method for preparing this fresh concrete.

Description

The invention relates to fresh concrete and a dry mix for its preparation.

It also relates to a concrete building element or a precast made of this concrete.

In addition, the invention also relates to a process for preparing this fresh concrete.

Prior art

According to qualified estimates, approximately 6.5 billion tons of inert construction demolition waste are produced worldwide each year. The vast majority of this is landfilled, and only a relatively small part is further used or processed - but most often in a way that does not use the full potential of this material, and where this material serves de facto only as a filler of some space. Crushed or ground inert construction demolition waste is used mainly for backfilling and backfilling of engineering networks (substitute for sorted gravel sands), for backfilling of car parks, roads, concrete structures of floors of buildings and halls, backfilling of bridge fronts, strengthening and leveling forest and field roads (substitute gravel). ), possibly for embankments of earth bodies of roads, railway bodies, anti - flood dikes (as a substitute for soil), etc.

In addition, methods for preparing concrete are also known, in which crushed or ground inert construction demolition waste is used as a replacement for part of the aggregate. A common disadvantage of these processes, which are typically represented by, for example, the process described in CN 105036660, and which are based on standard procedures for the preparation of standard concretes, is that the concretes prepared by them either do not achieve the required mechanical and physical parameters or only the cost of a large addition of cement (and the associated increase in production costs).

. / Ί PS4148EN

It is therefore an object of the present invention to provide a method for preparing concretes by replacing as much of the aggregate as possible with recycled material by grinding or crushing inert construction demolition waste, which would allow concrete preparation with mechanical and physical parameters comparable to conventional concrete without requiring above-standard addition of cement or other components.

In addition, it is also an object of the invention to provide such concretes and dry mixes prepared in this way.

The essence of the invention

The object of the invention is achieved by fresh concrete, the essence of which consists in that in 1 m ^{3 it} contains 135 to 250 kg of water, 135 to 400 kg of cement, 28 to 52 kg of silica fume and 1000 to 2000 kg of aggregate, while 40 to 100% of aggregate consists of recycled material from inert construction demolition waste, 0 to 30% of aggregate consists of natural aggregates (mined and / or crushed) and 0 to 30% of aggregates consists of light artificial aggregates and / or slag and / or slag and / or polystyrene and / or at least one organic filler, optionally another component for improving the thermal and / or acoustic and / or fire-retardant properties of hardened concrete.

In an advantageous embodiment the concrete in 1 m ³ contains 180 to 230 kg of water, 170 to 210 kg of cement, 35 to 45 kg of silica fume and from 1355 to 1660 kg brick recycled material, which is recycled from the inert structural demolition waste which is completely or at least the majority consists of brick crumb (with a possible admixture of crumbs from other building materials and / or materials), or ceramic recycled material, which is a recycle of inert construction demolition waste, which completely or at least mostly consists of ceramic crumb from ceramic construction and equipment elements, such as paving, tiling, ceramic sanitary products, fired tiles, etc. (with possible admixture of crumb from other building materials and / or materials) or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed inert construction demolition waste waste, which usually contains bricks, concrete and ceramic building and furnishing elements in various proportions (with possible admixture <: PS4148CZ building materials and / or materials). The recycled fraction is preferably 0 to 16 mm or 0 to 8 mm. However, it can also be higher.

In another preferred embodiment variant, the concrete according to the invention contains in 1 m ³ 170 to 235 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume and 945 to 1250 kg of brick or ceramic or mixed recyclates from inert construction demolition waste, with fraction recycled 0 to 16 mm, resp. 0 to 8 mm, in combination with 350 to 515 kg of natural aggregates with an upper fraction of up to 16 mm, resp. up to 8 mm, preferably up to 4 mm, or 165 to 250 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume and 685 to 1075 kg of brick or ceramic or mixed recyclates from inert construction demolition waste with recycled fraction 0 to 16 mm, resp. 0 to 8 mm, in combination with 450 to 845 kg of recycled concrete, which is recycled from inert construction demolition waste, which consists entirely or at least of the majority of concrete crumb or crumb of other cement-containing material, such as cement mortar, concrete screed, etc. (with possible admixture of crumb from other building materials and / or materials). The recycled concrete preferably has a fraction of 0 to 16 mm, resp. 0 to 8 mm.

In another preferred embodiment variant, this concrete in 1 m ³ contains 155 to 220 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume and 1025 to 1320 kg of recycled concrete with a fraction of 0 to 16 mm, resp. 0 to 8 mm, in combination with 450 to 585 kg of natural aggregates with an upper fraction of up to 16 mm, resp. up to 8 mm, preferably up to 4 mm.

If necessary, it may further comprise at least one admixture or a mixture of two or more admixtures in the concrete in a total amount of up to 5% by weight. batches of cement.

In addition, the object of the invention is also achieved by a dry mix for the preparation of fresh concrete, the composition of which corresponds to the composition of fresh concrete, but without the mixing water.

Several different processes can be used for the preparation of the concrete according to the invention, which together form a single inventive idea, and differ from each other only in the specific amount of raw materials and the type of recyclates used.

. 'PS4148CZ

In one variant, a two-fractional brick or ceramic or mixed recyclate from inert construction demolition waste is mixed with recycled fractions, preferably 0 to 8 mm and 8 to 16 mm, in a forced circulation mixer for 20 to 40 seconds. After mixing, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. Then the whole batch of cement is added to it with constant stirring over 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. Subsequently, with constant stirring, it is sprayed with a whole batch of mixing water for 40 to 60 seconds or the whole batch of mixing water is sprayed on it within 40 to 60 seconds. After another 80 to 160 seconds of mixing, fresh concrete is prepared, which is 100% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

In another variant, a two-fractional brick or ceramic or mixed recyclate from inert construction demolition waste is mixed with recycled fractions, preferably 0 to 8 mm and 8 to 16 mm, in a forced circulation mixer for 20 to 40 seconds. After mixing, a two-fraction recycled concrete is added to it with constant stirring, with fractions preferably 0 to 8 mm and 8 to 16 mm, or natural aggregate with an upper fraction preferably up to 16 mm (up to 30% by weight of total aggregate) and the mixture thus formed is stirred for another 20 to 40 seconds. Then, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After mixing, the entire batch of cement is added while stirring for 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. Subsequently, with constant stirring, it is sprayed with a whole batch of mixing water for 40 to 60 seconds or the whole batch of mixing water is sprayed on it within 40 to 60 seconds. After a further 80 to 160 seconds of mixing, fresh concrete is prepared, which is 70 to 100% by weight. aggregates are made from recycled inert demolition waste.

; PS4148CZ

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

In another variant, a two-fractioned dusted recycled concrete recycle is mixed with fractions of preferably 1 to 8 and 8 to 16 mm in a forced circulation mixer for 20 to 40 seconds. After mixing, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After mixing, the entire batch of cement is added to it with stirring over a period of 10 to 20 seconds, and the dry mixture thus formed is mixed for another 40 to 80 seconds. Subsequently, while stirring for 40 to 60 seconds, it is sprayed with a whole batch of mixing water or the whole batch of mixing water is sprayed on it within 40 to 60 seconds. After another 80 to 160 seconds of mixing, fresh concrete is prepared, which is 100% by weight. aggregates are made from recycled inert demolition waste. 15 The preparation of the dry mix for the preparation of such fresh concrete then takes place analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

In another variant, the two-fraction recycled concrete with the fractions, preferably 0 to 8 mm and 8 20 to 16 mm, is mixed in a forced circulation mixer for 20 to 40 seconds. After mixing, natural aggregate with an upper fraction, preferably up to 16 mm (max. Up to 30% by weight of total aggregate), is added to it with constant stirring, and the mixture thus formed is mixed for another 20 to 40 seconds. Then, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After it has been mixed, the entire batch of cement is added to it with constant stirring over a period of 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. Subsequently, with constant stirring, it is sprayed with a whole batch of mixing water for 40 to 60 seconds or the whole batch of mixing water is sprayed on it within 40 to 60 seconds. After a further 80 to 160 seconds of mixing, fresh concrete is prepared in which at least 70% by weight. aggregates are made from recycled inert demolition waste.

'. : · PS4148EN ¹

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

In the case where recycled material and possibly natural aggregates with an upper fraction up to 8 mm are used, concrete with a finer texture, sometimes referred to as cement or concrete mortar, is prepared by the same procedures.

In all variants, at least one admixture or a mixture of two or more admixtures for the concrete can be dissolved in the mixing water in a total amount of up to 5% by weight. batches of cement.

As natural aggregate, mined and / or crushed natural aggregate with a fraction of 0 to 4 mm is preferably used.

In other variants, the recycled material from inert construction demolition waste with the upper fraction is preferably mixed for 20 to 40 seconds in a forced circulation mixer, preferably up to 16 mm or up to 8 mm of the first composition, after mixing it is added recycled material from inert construction demolition waste. waste with the upper fraction preferably up to 16 mm or up to 8 mm of the second composition and the mixture thus formed is mixed for 20 to 40 seconds and then natural aggregate with the upper fraction preferably up to 16 mm or up to 8 mm is added and the mixture thus formed is stirs for another 20 to 40 seconds. Subsequently, 28 to 52 kg of silica fume is added to it over a period of 10 to 15 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds, and after mixing, 135 to 400 kg of cement is added thereto over 10 to 20 seconds with constant stirring. The mixture thus formed is stirred for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed with stirring for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after a further 80 to 160 seconds mixing, fresh concrete is prepared in which at least 70% of the aggregate is recycled from inert construction demolition waste. In this case, the brick or ceramic or mixed recycled material is preferably metered into the mixer, then the concrete recycled material and then the natural aggregate.

All components of the concrete or dry mix are dosed while the mixer is running. However, it is possible to temporarily stop the mixer run after mixing the already inserted components, and before adding the next component, or if this run is stopped. even PS4148CZ it allows the design of the mixer, to insert another component to turn. However, these modifications to the mixer run have no effect on the properties or consistency of the fresh concrete (or dry mix) being prepared, nor on the subsequently hardened concrete and its properties.

If necessary, in any process, at least one refining admixture may be added to the mixture prior to the addition of the silica fume to improve the thermal and / or acoustic and / or fire protection properties of the concrete, such as lightweight aggregate (agloporite, expanded clay, expandite, expanded perlite, under .), slag, slag, at least one organic filler (wood sawdust, shavings, rice husks, shingles, etc.), polystyrene, etc. in an amount of up to 30 wt. aggregates, preferably up to 20 or up to 15% by weight. total aggregates. This component is added with constant stirring and mixed with the other aggregate-forming components for 20 to 40 seconds.

Examples of embodiments of the invention

The method for preparing concrete according to the invention is based on a combination of a specific concrete composition and a specific process, which in combination with each other make it possible to replace up to 100% by weight. aggregates in concrete with recycled inert construction demolition waste (ie ground or crushed inert construction demolition waste) and at the same time achieve mechanical-physical parameters that are at least comparable with standard concretes.

The recycled inert construction waste can have essentially any fraction according to the use and requirements for the concrete, but preferably it has a fraction of 0 to 16 mm or 1 to 16 mm (if only recycled concrete is used as aggregate), or 0 to 8 mm or 1 up to 8 mm (if only recycled concrete is used as aggregate).

The fresh concrete prepared in this way contains in 1 m ³ 135 to 250 kg of water, 135 to 400 kg of cement, 28 to 52 kg of silica fume and 1000 to 2000 kg of aggregate, with 40 to 100 wt. of this aggregate consists of a brick or ceramic or mixed recyclate from inert construction demolition waste with a fraction preferably 0 to 16 mm (in a preferred variant it is a two-fraction recycled with fractions 0 to 8 mm and 8 to 16 mm), or 0 to 8 mm ,. . _: · · PS4148CZ and / or recycled concrete with a fraction preferably 0 to 16 mm (in a preferred variant it is a two-fraction recycled with fractions 0 to 8 mm and 8 to 16 mm), resp. 1 to 16 mm (in a preferred variant it is a two-fraction recyclate with fractions of 1 to 8 mm and 8 to 16 mm), or 0 to 8 mm, resp. 1 to 8 mm.

For the purposes of this application, recycled brick means recycled material formed by crushing or grinding inert construction demolition waste, which is wholly or at least made up of bricks, with possible admixtures of other building materials and / or materials (concrete, ceramic building and furnishing items, residues mortar, plaster, construction glue, etc.). The recycled brick thus consists entirely or at least of the vast majority of brick crumb, with a possible admixture of crumb from other building materials and / or materials. Recycled ceramic means recycled material formed by crushing or grinding inert construction demolition waste, which is wholly or at least mostly made up of ceramic construction and furnishing items, such as paving, tiling, ceramic sanitary products, fired tiles, etc., with possible admixtures of other building materials and / or materials (concrete, bricks, mortar residues, plaster, construction glue, etc.). The recycled ceramic material thus consists entirely or at least of the vast majority of ceramic crumb, with an optional admixture of crumb from other building materials and / or materials. Recycled concrete means a recycled material created by crushing or grinding inert construction demolition waste, which consists entirely or at least of the majority of concrete or other material containing cement (eg concrete screed, cement mortar, etc.), with possible admixtures of other building materials or materials (bricks, ceramic construction and furnishing items, mortar residues, plaster, construction glue, etc.). The recycled concrete material thus consists entirely or at least of the vast majority of crumb made of concrete or other material containing cement, with an optional admixture of crumb made of other building materials and / or materials. Mixed recycled material is then a recycled material formed by crushing or grinding mixed inert construction demolition waste, which consists of a mixture of different building materials and materials, usually bricks, concrete and ceramic construction and furnishing items in different proportions, with possible admixture of mortar residues, <PS4148EN plasters, gypsum, construction glue, etc. The mixed recyclate is thus formed by crumb from mixed construction demolition waste.

The fractions of all these recyclates can be arbitrary according to the intended use and concrete requirements, preferably they are 0 to 16 mm, or 1 to 16 mm, resp. 0 to 8 mm or 1 to 8 mm.

Any remaining part of the aggregate - max. Up to 30% by weight, is then formed by natural aggregate (mined and / or crushed) with the upper fraction preferably up to 16 mm, resp. up to 8 mm or up to 4 mm. Another 0 to 30 wt. aggregates, preferably 0 to 20 or 0 to 15 wt. The aggregate can then, if desired, be formed by at least one known finishing admixture which improves the thermal and / or acoustic and / or fire-retardant properties of the concrete and which is commonly used in standard concretes. Such a finishing admixture is, for example, a light artificial aggregate (such as agloporite, expanded clay, expandite, expanded perlite, etc.), slag, slag, polystyrene or at least one organic filler (such as wood sawdust, shavings, rice husks, shingles, etc.) etc.

When using recycled material from inert construction demolition waste and possibly also natural aggregate with a fraction of 0 to 8 mm, fresh concrete with a finer texture, sometimes referred to as cement or concrete mortar, is prepared.

In preferred embodiments, the fresh concrete in 1 m ³ contains 180 to 230 kg of water, 170 to 210 kg of cement, 35 to 45 kg of silica fume and 1355 to 1660 kg of brick or ceramic or mixed recycled waste from inert construction demolition waste with a recycled fraction of 0 to 16 mm, resp. 0 to 8 mm, or 170 to 235 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume and 945 to 1250 kg of brick or ceramic or mixed recycled from inert construction demolition waste with a recycled fraction of 0 to 16 mm, resp. 0 to 8 mm, in combination with 350 to 515 kg of natural aggregates with an upper fraction of up to 16 mm, resp. up to 8 mm, optionally up to 4 mm, or 165 to 250 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume and 685 to 1075 kg of brick or ceramic or mixed recycled from inert construction demolition waste with recycled fraction 0 to 16 mm, resp. 0 to 8 mm, in combination with 450 to 845 kg of recycled concrete with a fraction of 0 to 16 mm, resp. 0 to 8 mm, or 155 to 220 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume and 1025 to 1320 kg of recycled concrete with a fraction of 0 to 16 mm, resp. 0 to 8 mm,

PS4148CZ in combination with 450 to 585 kg of natural aggregates with the upper fraction up to 16 mm, resp. up to 8 mm, preferably up to 4 mm.

If necessary, the fresh concrete according to the invention may in any variant contain at least one additive or a mixture of two or more concrete admixtures in a dose of at most 5% by weight. batches of cement. Such an admixture can be any known admixture, such as an admixture for vibropressed concrete and / or admixtures according to EN 934-2. These admixtures include in particular water-reducing (plasticizing) and strongly water-reducing (superplasticizing) additives to improve the consistency of concrete, to reduce the water dose, improve the strength and some other properties of fresh and hardened concrete, stabilizing, aerating, accelerating setting and hardening of concrete, slowing down solidification, sealing, etc.

For thorough mixing of individual components and preparation of concretes (or dry mixtures) of the desired structure and properties, any mixer with forced circulation is used, preferably a mixer with radial movement of mixing arms, or with double simultaneous radial movement of mixing arms (such as the mixer described in IT 1244970 or EP 0508962), in which all its inner surfaces are wiped off. However, it is necessary to observe not only the above-mentioned composition of the concrete, but also the mixing times and the dosing of the individual components into the mixer (see Examples 1 to 4 and 8 to 11 below). All components are metered in while the mixer is running. However, it is possible to temporarily stop the mixer run after mixing the already inserted components, and before adding the next component, or to reverse this run, if the design of the mixer allows, to insert some other component and mix it with the other components. However, these modifications to the mixer run have no effect on the properties or consistency of the fresh concrete (or dry mix) being prepared, nor on the subsequently hardened concrete and its properties.

The recycle of inert construction demolition waste is sanitized prior to preparing the concrete or dry mix of the field of the invention, e.g., by water or steam bath or otherwise, thereby reducing the number of (pathogenic) organisms and microorganisms contained therein.

Silica fly ash, which serves as a binder in the standard preparation of standard concretes from natural aggregates, serves in the preparation of concrete according to

- PS4148EN of the invention as a filler when, following the dosing method described below and the mixing method described above, it fills the overall lattice structure of the concrete, coats the recycled particles and fills the pores therein. Thanks to this, there is no agglomeration of fine particles and the resulting concrete has a lower porosity and after hardening it reaches mechanical and physical parameters comparable to standard concretes.

In all variants, cement with a specific surface area of at least 330 m ² .kg ^-1 or more is used (eg cement of class CEM I 42.5 or higher). Its dosing in the manner described below ensures the formation of a suitable bond between the cement and the recycled already coated silica fume and a very good homogenization of the mixed mixture.

After forming and mixing the dry mixture of the above components, the mixture is sprayed with the mixing water in the mixer with constant stirring, or the mixing water is sprayed on it. In this method of dosing the mixing water in combination with constant mixing in a forced circulation mixer, the cement surface is gradually moistened and the formed cement putty is gradually adhered to recycled grains already coated with silica, thus preventing agglomeration of fresh concrete particles, separation of fine particles and separation. water, and ensure the required consistency of fresh concrete. In addition, this method of dosing activates the silica contained in the fine particles of recycled and silica fume, and thus the latent hydraulics of these components, which allows concretes prepared in this way to achieve physico-mechanical parameters comparable to standard concretes, even with a cement dose that it can be lower than with standard concretes (in some variants 190 to 230 kg / m ³ - see eg examples 5, 6 and 7).

The mixing water must correspond to the quality of drinking water. If necessary, it may contain (dissolved or undissolved) at least one known standard concrete admixture.

To supplement the recycled material from inert construction demolition waste, it is possible to use natural aggregates (mined and / or crushed) with an upper fraction, preferably up to 16 mm, resp. up to 8 mm, or even small mined aggregates with a fraction of 0 to 4 mm.

- J; _; : PS4148CZ

Below are described four exemplary processes for the preparation of fresh concrete (and dry mix for the preparation of this concrete) according to the invention - the first of which for the case where it is 100% by weight. aggregates consisting of a two-fraction mixed recyclate from inert construction demolition waste, with recycled fractions 0 to 8 mm and 8 to 16 mm, the second for the case where the aggregate consists of a two-fraction mixed recyclate from inert construction demolition waste, with recycled fractions 0 to 8 mm and 8 up to 16 mm in combination with two-fraction recycled concrete with fractions 0 to 8 mm and 8 to 16 mm or natural aggregates with an upper fraction up to 16 mm (up to 30% by weight of total aggregates), the third for the case where 100% by weight aggregates consist of two-fraction recycled concrete with fractions 1 to 8 mm and 8 to 16 mm, and the fourth for the case where the aggregate consists of two-fraction recycled concrete with fractions 0 to 8 mm and 8 to 16 mm in combination with natural aggregate with upper fraction up to 16 mm (up to 30% by weight of total aggregates). As will be apparent to one skilled in the art, the intervals, resp. the times of addition of individual components and the amount of these components are given by the technological requirements for hardened concrete and its mechanical-physical parameters, and can vary within the entire intervals listed below. Likewise, in other examples, the upper fraction of recycled material (s) and / or natural aggregate may be higher than 16 mm.

In other variants, it is possible to analogously combine brick or ceramic or mixed recycled material from inert construction demolition waste with recycled concrete and up to 30% by weight within the aggregate. natural aggregates. In this case, the brick or ceramic or mixed recyclate from inert construction demolition waste is preferably metered into the mixer first, then the concrete recyclate and then the natural aggregate. Brick, ceramic or mixed recycled waste from inert construction demolition waste has similar properties and behavior and can therefore be interchanged or mixed with each other.

Example 1

To prepare the concrete according to the invention, a two-fractional mixed recyclate from inert construction demolition waste, with recycled fractions 0 to 8 mm and 8 to 16 mm, is mixed for 20 to 40 seconds in a mixer with forced circulation and radial or double simultaneous radial movement of the mixing arms. After his

After stirring, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. Then the whole batch of cement is added to it with constant stirring over 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. It is then sprayed with a full batch of mixing water (which contains at least one concrete admixture if necessary) or the entire batch of mixing water (which contains at least one concrete admixture if necessary) is stirred for 40 to 60 seconds with stirring for 40 to 60 seconds. Spray for 60 seconds. After another 80 to 160 seconds of mixing, fresh concrete is prepared, which is 100% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

Example 2

To prepare the concrete according to the invention, a two-fractional mixed recyclate from inert construction demolition waste, with recycled fractions 0 to 8 mm and 8 to 16 mm, is mixed for 20 to 40 seconds in a mixer with forced circulation and radial or double simultaneous radial movement of the mixing arms. After mixing, a two-fraction recycled concrete with fractions 0 to 8 mm and 8 to 16 mm or natural aggregate with an upper fraction up to 16 mm (up to a maximum of 30% by weight of the total aggregate) is added to it with constant stirring and the mixture thus formed is stirs for another 20 to 40 seconds. Then, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After it has been mixed, the entire batch of cement is added to it with constant stirring over a period of 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. It is then sprayed with a full batch of mixing water (which contains at least one concrete admixture if necessary) or the entire batch of mixing water (which contains at least one concrete admixture if necessary) is stirred for 40 to 60 seconds with stirring for 40 to 60 seconds. Spray for 60 seconds. After another 80 to 160 seconds. . . PS4148CZ mixing, fresh concrete is prepared, which is 70 to 100% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

Example 3

For the preparation of the concrete according to the invention, a two-fraction dusted recycled concrete recycle with fractions 1 to 8 and 8 to 16 mm is mixed in a forced circulation mixer with radial or double simultaneous radial movement of the mixing arms for 20 to 40 seconds. After mixing, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After mixing, the entire batch of cement is added to it with stirring over a period of 10 to 20 seconds, and the dry mixture thus formed is mixed for another 40 to 80 seconds. It is then sprayed with a full batch of mixing water (which contains at least one concrete admixture if necessary) or the entire batch of mixing water (which contains at least one concrete admixture if necessary) is stirred for 40 to 60 seconds with stirring for 40 to 60 seconds. Spray for 60 seconds. After another 80 to 160 seconds of mixing, fresh concrete is prepared in which 100 wt. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

Example 4

For the preparation of the concrete according to the invention, a two-fraction recycled concrete with 0 to 8 mm and 8 to 16 mm fractions is mixed in a forced circulation mixer with a radial or double simultaneous radial movement of the mixing arms for 20 to 40 seconds. After mixing, natural aggregate with an upper fraction up to 16 mm (max. Up to 30% by weight of total aggregate) is added to it with constant stirring and. : .J.;. PS4148CZ The mixture thus formed is stirred for another 20 to 40 seconds. Then, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After it has been mixed, the entire batch of cement is added to it with constant stirring over a period of 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. It is then sprayed with a full batch of mixing water (which contains at least one concrete admixture if necessary) or the entire batch of mixing water (which contains at least one concrete admixture if necessary) is stirred for 40 to 60 seconds with stirring for 40 to 60 seconds. Spray for 60 seconds. After a further 80 to 160 seconds of mixing, fresh concrete is prepared with at least 70% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

In all cases, after the addition of the last aggregate component (ie recycled or natural aggregate) and at the same time before adding the silica fume to the mixture formed, it is possible to add at least one known finishing admixture which improves the thermal and / or acoustic and / or fire protection properties of concrete and which is commonly used for standard concretes. Such a finishing admixture is, for example, a light artificial aggregate (such as agloporite, expanded clay, expandite, expanded perlite, etc.), slag, slag, polystyrene or at least one organic filler (such as wood sawdust, shavings, rice husks, pazdeří etc.) etc. This component then makes up up to 30% by weight. aggregates, preferably up to 20% by weight. or up to 15 wt. total aggregates.

Below, for illustration, a total of 11 specific examples of fresh concrete prepared by the method according to the invention are given with the results of tests of these fresh and subsequently hardened concretes (after 7 and 28 days). The ratio of the recycled fractions in these examples is 40% by weight. fraction 0 to 8 mm, resp. 1 to 8 mm, and 60 wt. fractions of 8 to 16 mm, but in general their ratio may be 30:70 to 50:50.

. : PS4148CZ

Example 5

Following the procedure described in Example 1, 1 m ^{3 of} concrete was prepared, which contained 1505 kg of two-fraction mixed recyclate from inert construction demolition waste with recycled fraction 0 to 8 mm and 8 to 16 mm, 40 kg of silica fume (MICROSILICA-SIOXID®, manufactured by OFZ, as, Istebné, Slovak Republic), 190 kg of cement and 205 kg of water.

The fresh concrete thus prepared was subjected to a consistency test in accordance with EN 12350-2, the measured settlement value of 35 mm corresponding to grade S1. In addition, it was subjected to air content measurement according to EN 12350-7, with an average air content of 3.4% corresponding to standard non-aerated concrete.

From this fresh concrete, cubes with an edge of 150 mm were formed for the compressive strength test according to EN 12390-3, prisms with dimensions of 100 mm x 100 mm x 400 mm for the flexural tensile test according to EN 12390-5, for measuring volume changes according to ČSN 73 1320, measurement of static modulus of elasticity according to ISO 1920-10 and boards with dimensions of 200 mm x 200 mm x 50 mm for thermal conductivity test. After the concrete had hardened, the test specimens were demolded the next day and stored in an air-conditioned chamber at a temperature of 20 ± 2 ° C and a relative humidity above 95% for the respective tests. During these tests, the following parameters were measured: compressive strength (average of three measurements) after 7 days 19.7 MPa, compressive strength (average of three measurements) after 28 days 32.0 MPa, flexural tensile strength after 28 days 2 .6 MPa, volume changes of concrete 1.278% o (after 28 days), static modulus of elasticity 12.5 GPa, thermal conductivity 0.46 W / (mK).

In addition, the chloride content of this concrete was determined according to EN 196-2 and EN 1744-1, which was 0.118%, in accordance with Decree No. 307/2002 Coll. Of the State Office for Nuclear Safety on radiation protection, as amended, the content of natural radionuclides, which was 27 Bq / kg, and the mass activity index, which was 0.40, both of which meet the requirements of this Decree for use in residential or residential buildings. living rooms (mass activity ²²⁶ Ra <150 Bq.kg ¹ , mass activity index I <0.5). In accordance with EN 12457 and Decree of the Ministry of the Environment No. 294/2005 Coll. its ecotoxicity was determined to be satisfactory. The criteria for determining ecotoxicity are given in Table 1.

PS4148CZ

Table 1

Test organism Exposure time [hours] AND II On the water arthropod Daphnia magna 48 Max. immobilization 30% Max. immobilization 30% On the aquatic vertebrate Poecillia reticulata 96 without death and behavior change without death and behavior change On the alga Desmodesmus subspicatus 72 Max. 30% inhibition Max. change in growth 30% On the seeds of the plant Sinapis alba 72 Max. 30% inhibition Max. change in growth 30%

With its mechanical and physical parameters, this particular concrete corresponds to 5 standard concretes of strength class C 20/25 and classification classes of use specification X0, XC1 and XC2 according to ČSN EN 206 - see Table 2.

Table 2

Classification class Description of the degree of environmental influence Example of the occurrence of the degree of environmental influence for concrete without risk of corrosion or disturbance XO For concrete without reinforcement or built-in metal inserts. All effects except freezing and thawing, abrasion or chemically aggressive environments Concrete inside buildings with very low humidity For concrete with reinforcement or with built-in metal inserts: Very dry for concrete with a risk of corrosion due to carbonation XC1 Dry or still wet. Concrete inside buildings with low humidity; Concrete permanently immersed in water. XC2 Wet, sometimes dry. Concrete surface exposed to long-term exposure to water; Most of the basics. XC3 Medium wet, humid. Concrete inside buildings with medium or high humidity; Outdoor concrete protected from rain. XC4 Alternately wet and dry Concrete surfaces in contact with water, which are not included in the degree of influence of the environment XC2

PS4148CZ

Classification class Description of the degree of environmental influence Example of the occurrence of the degree of environmental influence _________________ ' for concrete with a risk of corrosion due to chlorides, but not from seawater__________ XD1 Medium wet, humid. Concrete surfaces exposed to chlorides dispersed in the air. XD2 Wet, sometimes dry. Swimming pools. Concrete exposed to industrial waters containing chlorides. for concrete exposed to frost and thawing, without chemical de-icing agents _______________________________________________________________ XF1 Slightly saturated with water without defrosting agents. Vertical concrete surfaces exposed to rain and frost.

Example 6

In the manner described in Example 2, a total of 7 samples of fresh concrete according to the invention were formed, the composition of 1 m ^{3 of} each of which is described in Table 3.

Table 3

Sample Folder CB 1/1 CB 1/2 CB 1/4 CB 1/7 CB 1/9 CB 1/10 CB 1/11 Natural aggregates, fraction 0 to 4 mm [kg] 420 390 0 465 0 450 0 Mixed recyclate from inert construction demolition waste, fractions 0 to 8 and 8 to 16 mm [kg] 1 125 1 135 865 1 135 765 1 055 975 Recycled concrete, fractions 0 to 8 and 8 to 16 mm [kg] 0 0 660 0 765 0 460 Silica flight [kg] 40 40 40 40 40 40 40 Cement [kg] 230 230 230 190 190 230 230 Plasticizing or superplasticizing admixture for concrete [kg] 0 0 0 0.95 0.92 1.17 1.31 Water [kg] 200 205 195 190 185 210 235 Bulk density of concrete 7 days old [kg / m ³ ] 1960 1970 1950 2010 1950 - - Bulk density of concrete aged 28 days [kg / m ³ ] 1950 1980 1990 1970 1950 - -

PS4148CZ

These concretes were subsequently subjected to the tests described in Example 5 and some of them additionally tested the leakage with pressurized water according to EN 12390-8, meeting the requirement for a maximum leakage of 50 mm, frost resistance test according to ČSN 73 1322 at 100 cycles. . 0.75, and the alkali silica expansion test according to ASTM C 1260-94 (prisms measuring 25 mm x 25 mm x 250 mm). The results of these tests are shown in Table 4.

Table 4

Sample Parameter CB 1/1 CB 1/2 CB 1/4 CB 1/7 CB 1/9 CB 1/10 CB 1/11 Consistency of fresh concrete cone seating [mm] 35 30 40 100 60 160 55 Air content in fresh concrete [%] 3.4 3.6 2.8 1.8 2.2 5.8 4.7 Compressive strength [MPa] - After 7 days - After 28 days 20.1 24.0 18.7 14.2 14.9 16.7 22.6 32.9 35.7 41.9 28.2 26.8 28.5 33.5 Flexural tensile strength after 28 days [MPa] 3.2 - 2.5 1.9 3.2 - - Depth of leakage with pressurized water [mm] 31 - 39 32 30 - - Volume changes of concrete [% o] 1,115 th most common - 0.964 - - - - Frost resistance [-] 100 cycles - 1.07 0.82 - 0.90 0.89 0.98 Static modulus of elasticity [GPa] - 17.5 16.0 17.5 16 Chloride content [%] 0.125 0.125 0.138 0.112 0.125 0.122 0.126 Alkali-silica expandability [%] - - - - - 0.037 0.028 Natural radionuclide content - Mass activity ²²⁶ Ra [Bq.kg '] - Mass activity index [-] - 24 20 - - - - - 0.41 0.32 - - - - Ecotoxicity satisfies satisfies satisfies satisfies satisfies Satisfies satisfies

. ::. '.. PS4148CZ

Table 5 then lists the strength classes of concrete to which the concrete falls due to its mechanical and physical parameters and the classification classes of the specification of the use of these concretes according to ČSN EN 206 (see Table 2).

Table 5

Sample CB 1/1 CB 1/2 CB 1/4 OJ C 30/37 CB 1/7 CB 1/9 CB 1/10 CB 1/11 Concrete strength class C 20/25 OJ C 25/30 C 16/20 C 16/20 C 20/25 C 20/25 Specifications for the use of concrete XO XC1 XC2 XO XC1 XC2 XC3 XC4 XD1 XD2 XF1 XO XC1 XC2 XC3 XC4 XD1 XD2 XF1 XO XC1 XO XC1 XO XC1 XC2 XO XC1 XC2

Example 7

In the manner described in Example 4, 3 samples of fresh concrete according to the invention were formed, the composition of 1 m ^{3 of} each of which is described in Table 6.

Table 6

Sample Folder CB 1/5 CB 1/6 CB 1/8 Natural aggregates, fraction 0 to 4 mm [kg] 500 515 530 Recycled concrete, fractions 0 to 8 and 8 to 16 mm [kg] 1165 1200 1140 Silica flight [kg] 40 40 40 Cement [kg] 230 190 190 Plasticizing or superplasticizing admixture for concrete [kg] 0 0 0.86 Water [kg] 200 185 175 Bulk density of concrete 7 days old [kg / m ³ ] 2050 2100 2030 Bulk density of concrete aged 28 days [kg / m ³ ] 2080 2110 2030

PS4148CZ

These concretes were then subjected to the tests described in Examples 5 and 6, with 50 cycles in the frost resistance test. The results of these tests are shown in Table 7.

Table 7

Sample Parameter CB 1/5 CB 1/6 CB 1/8 Consistency of fresh concrete cone seating [mm] 120 140 70 Air content in fresh concrete [%] 2.4 2.5 3.0 Compressive strength [MPa] - After 7 days - After 28 days 20.1 21.4 9.6 28.5 31.3 20.1 Flexural tensile strength after 28 days [MPa] 1.9 3.2 2.2 Depth of leakage with pressurized water [mm] - - 45 Volume changes of concrete [% o] - 1,226 th most common - Frost resistance [-] 50 cycles 0.85 - 0.90 Static modulus of elasticity [GPa] 14.5 20.5 15.5 Chloride content [%] 0.130 0.117 0.118 Natural radionuclide content - Mass activity ²²⁶ Ra [Bq.kg '] - Mass activity index [-] 15 - - 0.31 - - Ecotoxicity satisfies satisfies satisfies

Table 8 then lists the strength classes of concrete to which the concrete belongs due to its mechanical and physical parameters and the classification classes of the specification of the use of these concretes according to ČSN EN 206 (see Table 2).

PS4148CZ

Table 8

Sample CB 1/5 CB 1/6 CB 1/8 Concrete strength class C 16/20 C 20/25 OJ C 12/15 Specifications XO XO XC1 XO use of concrete XC1 z \ w 1 XC2

In case a brick or ceramic or mixed recyclate from inert construction demolition waste and / or recycled concrete with an upper fraction of 8 mm is used for the preparation of concrete, optionally in combination with natural aggregates with an upper fraction up to 8 mm, preferably with mined aggregates with fractions of 0 to 4 mm, the concrete is prepared analogously - see the following examples 8 to 11. The composition of fresh concrete and dry mixes differs from the variants described above only by the fraction of aggregate (or recycled and natural aggregate).

Below are described four further exemplary processes for the preparation of concrete (and dry mixes for the preparation of this concrete) according to the invention - the first of which for the case where it is 100% by weight. Aggregates consist of mixed recycled material from inert construction demolition waste with a recycled fraction of 0 to 8 mm, the second for the case where aggregate consists of mixed recycled material from inert construction demolition waste with a recycled fraction of 0 to 8 mm in combination with recycled concrete with a fraction of 0 to 8 mm or natural aggregates with an upper fraction up to 8 mm (up to 30% by weight of total aggregates), the third for the case where 100% by weight aggregates are made of recycled concrete with a fraction of 1 to 8 mm, and the fourth for the case where the aggregates are made of recycled concrete with a fraction of 0 to 8 mm in combination with natural aggregates with an upper fraction of up to 8 mm (up to 30% by weight of total aggregates). Here, too, it is obvious to a person skilled in the art that the intervals, resp. the times of addition of individual components and the amount of these components are given by the technological requirements for hardened concrete and its mechanical-physical parameters, and can vary within the entire intervals listed below. These processes then prepare concretes with a finer texture than in the previous examples, sometimes referred to as cement or concrete mortars. Their composition is the same as in the previous examples, except for the recycled / recycled fraction.

PS4148CZ

In other variants, it is then possible to analogously combine brick or ceramic or mixed recycled material with recycled concrete and with up to 30% by weight within the aggregate. natural aggregates. In this case, the brick or ceramic or mixed recyclate from inert construction demolition waste is preferably metered into the mixer first, then the concrete recyclate and then the natural aggregate. Brick, ceramic or mixed recycled waste from inert construction demolition waste has similar properties and behavior and can therefore be interchanged or mixed with each other.

Example 8

For the preparation of the concrete according to the invention, a mixed recycled material from inert construction demolition waste with a recycled fraction of 0 to 8 mm is mixed in a forced circulation mixer with a radial or double simultaneous radial movement of the mixing arms for 20 to 40 seconds. After mixing, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. Then the whole batch of cement is added to it with constant stirring over 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. It is then sprayed with a full batch of mixing water (which contains at least one concrete admixture if necessary) or the entire batch of mixing water (which contains at least one concrete admixture if necessary) is stirred for 40 to 60 seconds with stirring for 40 to 60 seconds. Spray for 60 seconds. After another 80 to 160 seconds of mixing, fresh concrete is prepared, which is 100% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

Example 9

For the preparation of the concrete according to the invention, the mixed recycled material from the inert construction demolition is mixed for 20 to 40 seconds in a mixer with forced circulation and radial or double simultaneous radial movement of the mixing arms.

J ·. . . - PS4148CZ

24 ...... ......

waste, with a recycled fraction of 0 to 8 mm. After mixing it, the recycled concrete with a fraction of 0 to 8 mm or natural aggregate with an upper fraction of up to 8 mm (up to a maximum of 30% by weight of the total aggregate) is added to it and constantly mixed, and the mixture thus formed is mixed for another 20 to 40 seconds . Then, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After it has been mixed, the entire batch of cement is added to it with constant stirring over a period of 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. It is then sprayed with a full batch of mixing water (which contains at least one concrete admixture if necessary) or the entire batch of mixing water (which contains at least one concrete admixture if necessary) is stirred for 40 to 60 seconds with stirring for 40 to 60 seconds. Spray for 60 seconds. After a further 80 to 160 seconds of mixing, fresh concrete is prepared, which is 70 to 100% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

Example 10

To prepare the concrete according to the invention, the dusted recycled concrete with a fraction of 1 to 8 mm is mixed in a forced circulation mixer with a radial or double simultaneous radial movement of the mixing arms for 20 to 40 seconds. After mixing, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After mixing, the entire batch of cement is added to it with stirring over a period of 10 to 20 seconds, and the dry mixture thus formed is mixed for another 40 to 80 seconds. It is then sprinkled with a full batch of mixing water (which contains at least one concrete admixture if necessary) or a whole batch of mixing water (which contains at least one admixture if necessary) is added with constant stirring for 40 to 60 seconds.

PS4148CZ concrete) will spray in 40 to 60 seconds. After another 80 to 160 seconds of mixing, fresh concrete is prepared, which is 100% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

Example 11

To prepare the concrete according to the invention, the recycled concrete with a fraction of 0 to 8 mm is mixed in a forced circulation mixer with a radial or double simultaneous radial movement of the mixing arms for 20 to 40 seconds. After mixing, natural aggregate with an upper fraction up to 8 mm (max. Up to 30% by weight of total aggregate) is added to it with constant stirring, and the mixture thus formed is mixed for another 20 to 40 seconds. Then, the entire batch of silica fume is added to it with stirring over a period of 10 to 15 seconds, and the mixture thus formed is stirred for another 40 to 80 seconds. After it has been mixed, the entire batch of cement is added to it with constant stirring over a period of 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds. Subsequently, it is sprinkled with a full batch of mixing water (which contains at least one concrete admixture if necessary) or a whole batch of mixing water (which contains at least one concrete admixture if necessary) is stirred for 40 to 60 seconds during 40 to 60 seconds. Spray for 60 seconds. After a further 80 to 160 seconds of mixing, fresh concrete is prepared with at least 70% by weight. aggregates are made from recycled inert demolition waste.

The preparation of the dry mix for the preparation of such fresh concrete then proceeds analogously, only without the addition of mixing water and with the use of dried recycled material and possibly also other components.

Also in these cases, after adding the last aggregate component (ie recycled or natural aggregate) and at the same time before adding the silica fume to the formed mixture, it is possible to add at least one known finishing admixture which improves the thermal and / or sound and / or fire protection properties of concrete, and

.. .. ...: PS4148CZ which is commonly used for standard concretes. Such a finishing admixture is, for example, a light artificial aggregate, such as agloporite, expanded clay, expandite, expanded perlite, etc.), slag, slag, polystyrene or at least one organic filler, such as wood sawdust, shavings, rice husks, shingles, etc. .) etc. This component then makes up up to 30% by weight. aggregates, preferably up to 20% by weight. or up to 15 wt. total aggregates.

The 0 to 16 mm aggregate fraction described in the above examples is not limiting for the practice of the invention, as both natural aggregate and recycled inert construction demolition waste may have a higher fraction limit.

All concretes according to the invention are intended for manual and machine processing (incl. Shotcrete) and are suitable for common concrete structures made of plain and ferrous concrete. In addition to fresh concrete (transport concrete) for the construction of houses, hotels, residential buildings, office buildings, industrial buildings, production halls, special-purpose facilities, medical facilities, etc., or parts thereof such as pillars, floors, shorter lintels (up to 6 m ), foundation slabs or footings, base concrete, etc., can also be used for the production of concrete products and precast units - eg concrete blocks and bricks, paving blocks, slabs, blocks, curbs, various elements of garden architecture, ceiling beams and inserts, etc.

In addition, all variants are concretes that are 100% recyclable in the same way as they were created.

Claims (54)

1. Fresh concrete, characterized in that it contains 135 to 250 kg of water, 135 to 400 kg of cement, 28 to 52 kg of silica fume and 1000 to 2000 kg of aggregate ^{in 1 m 3, 40 to 100% of the aggregate being recycled from inert} construction demolition waste, 0 to 30% of the aggregate consists of natural aggregate and 0 to 30% of the aggregate consists of at least one finishing admixture to improve the thermal and / or acoustic and / or fire-retardant properties of the concrete. Fresh concrete according to Claim 1, characterized in that 70 to 100% of the aggregate consists of recycled inert construction demolition waste and 0 to 30% of the aggregate consists of natural aggregate. Fresh concrete according to Claim 1 or 2, characterized in that 100% of the aggregate is recycled from inert construction demolition waste. Fresh concrete according to any one of claims 1 to 3, characterized in that the recyclate from inert construction demolition waste consists of a two-fractional recycled brick which consists wholly or at least of the majority of brick crumb, or a ceramic recyclate which is wholly or at least the vast majority consists of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with recycled fractions 0 to 8 and 8 to 16 mm and a mutual ratio of these fractions 30: 70 to 50:50, and / or the recycled material from inert construction demolition waste consists of a two-fractional recycled concrete, which consists wholly or at least of the majority of concrete crumb or crumb of another cement-containing material, with recycled fractions 0 to 8 and 8 to 16 mm and a mutual ratio of these fractions of 30:70 to 50:50, or a two-fraction recycled concrete with fractions of 1 to 8 mm and 8 to 16 mm and a ratio of these fractions of 30:70 to 50:50. . - PS4148CZ Fresh concrete according to any one of claims 1 to 3, characterized in that the recycled material consists of recycled brick, which consists entirely or at least of the majority of brick crumb, or ceramic recycled material, which consists entirely or at least of the majority of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with a recycled fraction of 0 to 8 mm, and / or concrete recycled material, which is wholly or at least mostly made up of concrete crushed or crushed from another cementitious material, with a recycled fraction of 0 to 8 or 1 to 8 mm. Fresh concrete according to Claim 4 or 5, characterized in that it contains 1000 to 1740 kg of brick or ceramic or mixed recycled material from inert construction demolition waste. Fresh concrete according to Claim 6, characterized in that it contains 180 to 230 kg of water, 170 to 210 kg of cement, 35 to 45 kg of silica fume and 1355 to 1655 kg of brick or ceramic or mixed recycled waste from inert construction demolition waste. Fresh concrete according to Claim 4 or 5, characterized in that it contains 695 to 1395 kg of brick or ceramic or mixed recycled material from inert construction demolition waste and 260 to 570 kg of natural aggregate. Fresh concrete according to Claim 8, characterized in that it contains 170 to 230 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume and 945 to 1250 kg of brick or ceramic or mixed recycled waste from inert construction demolition waste and 350 up to 515 kg of natural aggregates. Fresh concrete according to Claim 4 or 5, characterized in that it contains 525 to 1090 kg of brick or ceramic or mixed recycled material from inert construction demolition waste and 450 to 1065 kg of recycled concrete. Fresh concrete according to Claim 10, characterized in that it contains 165 to 250 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume, 685 to:. . P34148CZ 1075 kg of brick or ceramic or mixed recycled material from inert construction demolition waste and 450 to 845 kg of recycled concrete. Fresh concrete according to Claim 4 or 5, characterized in that it contains 820 to 1525 kg of recycled concrete and 350 to 600 kg of natural aggregate. Fresh concrete according to Claim 12, characterized in that it contains 155 to 220 kg of water, 170 to 255 kg of cement, 35 to 45 kg of silica fume, 1025 to 1320 kg of recycled concrete and 450 to 585 kg of natural aggregate. Fresh concrete according to any one of claims 1 to 13, characterized in that it further comprises at least one additive or a mixture of two or more concrete admixtures in a total amount of up to 5% by weight. batches of cement. Fresh concrete according to Claim 1, characterized in that the refining admixture is at least one admixture from the group of light artificial aggregates, slag, slag, polystyrene, organic filler. Dry mix for the preparation of 1 m ^{3 of} fresh concrete according to any one of claims 1 to 3, characterized in that it contains 135 to 400 kg of cement, 28 to 52 kg of silica fume and 1000 to 2000 kg of aggregate, wherein 40 to 100% of aggregate it consists of recycled material from inert construction demolition waste, 0 to 30% of the aggregate consists of natural aggregate and 0 to 30% of the aggregate consists of at least one refining admixture to improve the thermal and / or acoustic and / or fire-retardant properties of the concrete. Dry mix according to Claim 16, characterized in that 70 to 100% of the aggregate consists of recycled inert construction demolition waste and 0 to 30% of the aggregate consists of natural aggregate. Dry mixture according to Claim 16 or 17, characterized in that 100% of the aggregate is recycled from inert construction demolition waste. PS4148CZ Dry mixture according to any one of claims 16 to 18, characterized in that the recyclate from inert construction demolition waste consists of a two-fractional recycled brick recycled, which consists wholly or at least of the majority, of brick pulp, or a ceramic recycled which is wholly or at least of the vast majority consists of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with recycled fractions 0 to 8 and 8 to 16 mm and a mutual ratio of these fractions of 30:70 to 50:50, and / or consists of a two-fraction recycled concrete, which consists wholly or at least of the majority of concrete crumb or crumb of another cement-containing material, with recycled fractions 0 to 8 and 8 to 16 mm and a mutual ratio of these fractions of 30 : 70 to 50:50, or a two-fraction recycled concrete with fractions 1 to 8 mm and 8 to 16 mm and a mutual ratio of these fractions of 30:70 to 50:50. Dry mixture according to Claim 16, characterized in that the recycled material consists of recycled brick, which consists entirely or at least of the majority of brick crumb, or ceramic recycled material, which consists entirely or at least of the majority of ceramic crumb of ceramic construction and or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with a recycled fraction of 0 to 8 mm, and / or concrete recycled material, which consists wholly or at least of the majority consists of concrete crumb or crumb from other cementitious material, with a recycled fraction of 0 to 8 or 1 to 8 mm. Dry mixture according to Claim 19 or 20, characterized in that it contains 1000 to 1740 kg of brick or ceramic or mixed recycled material from inert construction demolition waste. Dry mixture according to Claim 21, characterized in that it contains 170 to 210 kg of cement, 35 to 45 kg of silica fume and 1355 to 1655 kg of brick or ceramic or mixed recycled waste from inert construction demolition waste. <. P34148CZ Dry mixture according to Claim 19 or 20, characterized in that it contains 695 to 1395 kg of brick or ceramic or mixed recycled material from inert construction demolition waste and 260 to 570 kg of natural aggregate. Dry mix according to claim 23, characterized in that it contains 170 to 255 kg of cement, 35 to 45 kg of silica fume and 945 to 1250 kg of brick or ceramic or mixed recycled from inert construction demolition waste and 350 to 515 kg of natural aggregate. Dry mix according to Claim 19 or 20, characterized in that it contains 525 to 1090 kg of brick or ceramic or mixed recycled material from inert construction demolition waste and 450 to 1065 kg of recycled concrete. Dry mix according to claim 25, characterized in that it contains 170 to 255 kg of cement, 35 to 45 kg of silica fume, 685 to 1075 kg of brick or ceramic or mixed recycled from inert construction demolition waste and 450 to 845 kg of recycled concrete. Dry mix according to Claim 19 or 20, characterized in that it contains 820 to 1525 kg of recycled concrete and 350 to 600 kg of natural aggregate. Concrete building element or precast, characterized in that it is at least partially made of concrete according to any one of claims 1 to 15. Process for the preparation of 1 m ^{3 of} fresh concrete according to any one of claims 1 to 3, characterized in that 1000 to 2000 kg of recycled material from inert construction demolition waste is mixed in a forced circulation mixer for 20 to 40 seconds, after mixing it to 28 to 52 kg of silica fume is added to it with constant stirring over a period of 10 to 15 seconds, the mixture thus formed is mixed for 40 to 80 seconds, and after mixing it is added to it while stirring for 10 to 20 seconds. 135 to 400 kg of cement, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed or stirred for 40 to 60 seconds with this amount of mixing water, and after a further 80 to 160 seconds of mixing, fresh concrete is prepared in which 100% of the aggregate is recycled from inert construction demolition waste. 30. A method for preparing fresh concrete according to claim 29, characterized in that 1000 to 1740 kg of two-fraction recycled brick recycled, which consists entirely or at least of the majority of brick crumb or ceramic recycled, are mixed for 20 to 40 seconds in a forced circulation mixer. , which consists wholly or at least of the majority consists of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with recycled fractions 0 to 8 mm and 8 to 16 mm and a ratio of these fractions of 30:70 to 50:50, after mixing it, 28 to 52 kg of silica fume is added to it with constant stirring for 10 to 15 seconds, the mixture thus formed is stirred for 40 to 80 seconds and after mixing it until 135 to 400 kg of cement are added with constant stirring over a period of 10 to 20 seconds, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 40 to 60 kg are mixed with constant stirring. 135 to 250 kg of mixing water is sprayed for seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing fresh concrete is prepared, in which 100% of the aggregate consists of brick, ceramic or mixed recycled from inert construction demolition waste. 31. A method for preparing fresh concrete according to claim 30, characterized in that 1355 to 1660 kg of two-fraction brick or ceramic or mixed recycled material from inert construction demolition waste is mixed with recycled fractions 0 to 8 in a forced circulation mixer for 20 to 40 seconds. mm and 8 to 16 mm and the mutual ratio of these fractions 30:70 to 50:50, after its mixing, 35 to 45 kg of silica fume is added to it with constant stirring for 10 to 15 seconds, the mixture thus formed is stirred for 40 to 80 seconds and after mixing, stirring therein for 10 to 20 seconds; PŠ4148CZ adds 170 to 210 kg of cement, while the mixture thus formed is mixed for another 40 to 80 seconds, after which 180 to 230 kg of mixing water is sprayed with stirring for 40 to 60 seconds, or this amount of mixing water is added to it within 40 to 60 seconds. sprayed, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, in which 100% of the aggregate consists of brick, ceramic or mixed recycled from inert construction demolition waste. 32. A method for preparing fresh concrete according to claim 29, characterized in that 1000 to 1740 kg of recycled brick, which consists entirely or at least of the majority of brick crumb or ceramic recycled material, are mixed for 20 to 40 seconds in a forced circulation mixer. which consists wholly or at least of the majority consists of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with a recycled fraction of 0 to 8 mm, after mixing to 28 to 52 kg of silica fume is added to it with constant stirring over a period of 10 to 15 seconds, the mixture thus formed is mixed for 40 to 80 seconds and, after mixing, 135 to 400 kg of cement are added to it with constant stirring over 10 to 20 seconds. the mixture thus formed is stirred for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed or stirred for 40 to 60 seconds with constant stirring for 40 to 60 seconds. d this amount of mixing water is sprayed, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, at which it is 100% by weight. aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste. 33. A method for preparing fresh concrete according to claim 32, characterized in that 1355 to 1655 kg of brick or ceramic or mixed recycled material from inert construction demolition waste is mixed with a recycled fraction of 0 to 8 mm in a forced circulation mixer for 20 to 40 seconds. , after mixing it, 35 to 45 kg of silica fume is added to it with constant stirring for 10 to 15 seconds, the mixture thus formed is mixed for 40 to 80 seconds, and after mixing it [PS4148EN is added to it with constant stirring for 10 to 20 seconds. 170 to 210 kg of cement, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 180 to 225 kg of mixing water are sprayed for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after a further 80 to 160 seconds of mixing, fresh concrete is prepared in which it is 100% by weight. aggregates consisting of brick, ceramic or mixed recycled material from inert construction demolition waste. 34. A method for preparing fresh concrete according to claim 29, characterized in that 1000 to 1800 kg of two-fractional recycled concrete, which is wholly or at least for the most part made up of crushed concrete or crushed stone from another, is mixed in a forced circulation mixer for 20 to 40 seconds. material containing cement, with recycled fractions of 1 to 8 mm and 8 to 16 mm and a mutual ratio of these fractions of 30:70 to 50:50, after its mixing, 28 to 52 kg of silica fume is added to it with constant stirring for 10 to 15 seconds , the mixture thus formed is mixed for 40 to 80 seconds, and after mixing it, 135 to 400 kg of cement is added to it with constant stirring for 10 to 20 seconds, while the mixture thus formed is mixed for another 40 to 80 seconds, after which 40 135 to 250 kg of mixing water is sprayed for up to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, in which 100% of the aggregate is b recycled ether. 35. A method for preparing fresh concrete according to claim 29, characterized in that 1000 to 1800 kg of recycled concrete, which is wholly or at least for the most part made up of concrete or other material, is mixed in a forced circulation mixer for 20 to 40 seconds. containing cement, with a recycled fraction of 1 to 8 mm, after mixing it, 28 to 52 kg of silica fume is added to it with stirring over a period of 10 to 15 seconds, the mixture thus formed is mixed for 40 to 80 seconds and after mixing it. 135 to 400 kg of cement are added over a period of 10 to 20 seconds, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 135 to 250 kg are sprayed with constant stirring for 40 to 60 seconds. PS4148CZ or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, at which it is 100% by weight. aggregates made of recycled concrete. A process for the preparation of 1 m ^{3 of} fresh concrete according to any one of claims 1 to 3, characterized in that the recycled recycled inert construction demolition waste of the first composition is mixed for 20 to 40 seconds in a forced circulation mixer. the recycle of inert construction demolition waste of the second composition or natural aggregate is added while stirring and the mixture thus formed is mixed for 20 to 40 seconds, then 28 to 52 kg of silica fume is added to it within 10 to 15 seconds, the mixture thus formed is mixed for 40 to 80 seconds and after mixing, 135 to 400 kg of cement are added to it with stirring over a period of 10 to 20 seconds, the mixture thus formed being mixed for another 40 to 80 seconds, after which 135 to 250 kg of mixing mixture are sprayed with constant stirring for 40 to 60 seconds. water, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, in which up to 100% of the aggregate is recycled from iner construction demolition waste. 37. A process for the preparation of fresh concrete according to claim 36, characterized in that 695 kg to 1395 kg of two-fraction recycled brick, which consists entirely or at least of the majority of brick crumb or ceramic, are mixed in a forced circulation mixer for 20 to 40 seconds. recycled material, which consists wholly or at least of the majority consists of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with recycled fractions 0 to 8 mm and 8 to 16 mm and the ratio of these fractions 30:70 to 50:50, after mixing it, 260 to 570 kg of natural aggregate with an upper fraction up to 16 mm is added to it with constant stirring, and the mixture thus formed is mixed for 20 to 40 seconds, after its mixing. stirring to it with constant stirring for 10 to 15. -: -; PŠ4148CZ seconds add 28 to 52 kg of silica fume, the mixture thus formed is mixed for 40 to 80 seconds and after its mixing 135 to 400 kg of cement is added to it with constant stirring for 10 to 20 seconds, while the mixture thus formed is mixed for another 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, in which case is at least 70% by weight. aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste. 38. A method for preparing fresh concrete according to claim 37, characterized in that 945 kg to 1250 kg of two-fractional brick or ceramic or mixed recycled material from inert construction demolition waste is mixed with recycled fractions 0 to 0 in a forced circulation mixer for 20 to 40 seconds. 8 mm and 8 to 16 mm and the ratio of these fractions 30:70 to 50:50, after mixing it, 350 to 515 kg of natural aggregate with an upper fraction up to 16 mm is added to it with constant stirring, and the mixture of aggregates thus formed is mixed for 20 up to 40 seconds, after mixing it is added to it with constant stirring for 10 to 15 seconds 35 to 45 kg of silica fume, the mixture thus formed is stirred for 40 to 80 seconds and after its mixing it is added to it with constant stirring for 10 to 20 seconds 170 to 255 kg of cement are added, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 170 to 235 kg of mixing water are sprayed or stirred for 40 to 60 seconds with this amount of mixing water. y is sprayed, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, at least 70% by weight. aggregates consisting of brick, ceramic or mixed recycled material from inert construction demolition waste. 39. A process for the preparation of fresh concrete according to claim 36, characterized in that 695 kg to 1395 kg of recycled brick, which consists entirely or at least of the majority of brick crumb or ceramic recycled material, are mixed for 20 to 40 seconds in a forced circulation mixer. , which consists wholly or at least of the majority consists of ceramic crumb of ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with a recycled fraction 0 '.:: - - PŠ4148CZ to 8 mm, after mixing it is added 260 to 570 kg of natural aggregate with an upper fraction up to 8 mm while stirring, and the mixture thus formed is mixed for 20 to 40 seconds, after mixing it is stirred for 5 to 5 mm. 20 to 52 kg of silica fume are added for 20 seconds, the mixture thus formed is stirred for 40 to 80 seconds and, after mixing, 135 to 400 kg of ce are added to it with constant stirring for 15 to 20 seconds. while the mixture thus formed is stirred for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed with stirring for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after a further 80 up to 160 seconds of mixing, fresh concrete with at least 70% by weight is prepared. aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste. 40. A process for the preparation of fresh concrete according to claim 39, characterized in that 950 kg to 1250 kg of brick or ceramic or mixed brick recycled fraction 0 to 8 mm is mixed in a forced circulation mixer for 20 to 40 seconds, after mixing it to 350 to 515 kg of natural aggregate is added to it with constant stirring, and the mixture of aggregate thus formed is mixed for 20 to 40 seconds, after its mixing, 35 to 45 kg of silica fume is added to it with constant stirring for 10 to 15 seconds. it is mixed for 40 to 80 seconds and, after mixing, 170 to 255 kg of cement are added to it with constant stirring for 10 to 20 seconds, the mixture thus formed being mixed for another 40 to 80 seconds, after which 170 to 230 kg of mixing water, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete with at least 70 wt. aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste. 41. A method for preparing fresh concrete according to claim 36, characterized in that in a forced circulation mixer with 20 to 40:. PŠ4148CZ seconds mixs 525 kg to 1090 kg of two-factional recycled brick, which is wholly or at least mostly made of crumb brick, or ceramic recycled, which is wholly or at least mostly made up of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumbs from mixed construction demolition waste, with recycled fractions 0 to 8 mm and 8 to 16 mm and a mutual ratio of these fractions 30:70 to 50:50, after its mixing is added to it with constant stirring 450 to 1065 kg of two-fraction recycled concrete, consisting wholly or at least of the majority of concrete crumb or crumb of other cement-containing material, with recycled fractions 0 to 8 mm and 8 to 16 mm and a mutual ratio of these fractions of 30:70 to 50: 50, and the mixture thus formed is stirred for 20 to 40 seconds, after mixing, 28 to 52 kg of silica are added thereto over 10 to 15 seconds with constant stirring. The mixture thus mixed is mixed for 40 to 80 seconds and, after mixing, 135 to 400 kg of cement are added to it with constant stirring over a period of 10 to 20 seconds, the mixture thus formed being mixed for a further 40 to 80 seconds. mixing for 40 to 60 seconds sprinkles 135 to 250 kg of mixing water, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing fresh concrete is prepared, at which it is 100% by weight. Aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste in combination with recycled concrete. 42. A process for the preparation of fresh concrete according to claim 41, characterized in that 685 kg to 1075 kg of two-fractional brick or ceramic or mixed recycled from inert construction demolition waste are mixed with recycled fractions 0 to 0 in a forced circulation mixer for 20 to 40 seconds. 8 mm and 8 to 16 mm and the mutual ratio of these fractions 30:70 to 50:50, after its mixing 450 to 845 kg of two-fraction recycled concrete is added with constant stirring, with recycled fractions 0 to 8 mm and 8 to 16 mm and a mutual ratio of these fractions of 30:70 to 50:50, and the mixture thus formed is mixed for 20 to 40 seconds, after its mixing, 35 to 45 kg of silica fume is added to it with stirring for 10 to 15 seconds, the mixture thus formed is mixes for 40 to 80 seconds, and after mixing, 170 to 255 kg of cement is added to it with stirring over a period of 10 to 20 seconds, and the mixture thus formed is mixed for another 40 to 80 seconds, after which 40 to 60 kg is mixed with constant stirring. seconds sprinkles 165 to 250 kg of mixing water, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, at which it is 100% by weight. Aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste in combination with recycled concrete. A method for preparing fresh concrete according to claim 36, characterized in that 525 kg to 1090 kg of recycled brick, which consists entirely or at least of the majority of brick crumb or ceramic recycled material, are mixed for 20 to 40 seconds in a forced circulation mixer. , which consists wholly or at least of the majority consists of ceramic crumb from ceramic construction and furnishing items, or mixed recycled material from inert construction demolition waste, which consists of crumb from mixed construction demolition waste, with a recycled fraction of 0 to 8 mm, after its mixing it is added with constant stirring 450 to 1065 kg of recycled concrete, which is completely or at least mostly made of concrete crumb or crumb of other cement-containing material, with a recycled fraction of 0 to 8 mm, and the mixture thus formed is mixed for 20 to 40 seconds , after mixing it, 28 to 52 kg of silica fume is added to it with constant stirring over a period of 10 to 15 seconds, the mixture thus formed is mixed 40 to 80 seconds and, after mixing, 135 to 400 kg of cement are added to it with stirring over a period of 10 to 20 seconds, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 135 to 60 seconds are sprayed while stirring for 40 to 60 seconds. 250 kg of mixing water, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, at which it is 100% by weight. Aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste in combination with recycled concrete. . : PS4148CZ 40 ' 44. A method for preparing fresh concrete according to claim 43, characterized in that 685 kg to 1075 kg of brick or ceramic or mixed recycled from inert construction demolition waste is mixed with a recycled fraction of 0 to 8 in a forced circulation mixer for 20 to 40 seconds. mm, after mixing it is added 450 to 845 kg of recycled concrete with a recycled fraction of 0 to 8 mm, and the mixture thus formed is mixed for 20 to 40 seconds, after mixing it is stirred for 10 to 35 to 45 kg of silica fume is added for 15 seconds, the mixture thus formed is mixed for 40 to 80 seconds and, after mixing, 170 to 255 kg of cement are added to it with constant stirring for 10 to 20 seconds, the mixture thus formed being mixed for another 40 to 80 seconds, after which 165 to 250 kg of mixing water are sprayed for 40 to 60 seconds with constant stirring, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh water is prepared. eton, in which 100 wt. Aggregates consist of brick, ceramic or mixed recycled material from inert construction demolition waste in combination with recycled concrete. 45. A process for the preparation of fresh concrete according to claim 36, characterized in that 820 kg to 1525 kg of two-fraction recycled concrete, which is wholly or at least for the most part consisting of crushed concrete or crushed concrete, are mixed in a forced circulation mixer for 20 to 40 seconds. other cement-containing material, with recycled fractions of 0 to 8 mm and 8 to 16 mm and a mutual ratio of these fractions of 30:70 to 50:50, after its mixing, 350 to 600 kg of natural aggregate with the upper fraction is added to it with constant stirring to 16 mm, and the mixture thus formed is stirred for 20 to 40 seconds, after mixing it is added to it with constant stirring for 10 to 15 seconds for 28 to 52 kg of silica fume, the mixture thus formed is stirred for 40 to 80 seconds, and after mixing it, 135 to 400 kg of cement are added to it with constant stirring over a period of 10 to 20 seconds, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed or mixed with it for 40 to 60 seconds. be This amount of mixing water is sprayed for 40 to 60 seconds, and after a further 80 to 160 seconds of mixing, fresh concrete is prepared in which at least 70% by weight. aggregates made of recycled concrete. PS4148CZ 46. A method for preparing fresh concrete according to claim 45, characterized in that 1025 to 1320 kg of two-fractional recycled concrete are mixed in a forced circulation mixer for 20 to 40 seconds, with recycled fractions of 0 to 8 mm and 8 to 16 mm and a mutual ratio of these fractions 30:70 to 50:50, after its mixing 450 to 585 kg of natural aggregate is added to it with constant stirring, and the mixture thus formed is mixed for 20 to 40 seconds, after its mixing it is formed with constant stirring for 10 to 15 35 to 45 kg of silica fume is added in seconds, the mixture thus formed is mixed for 40 to 80 seconds and after mixing it 170 to 255 kg of cement are added to it with constant stirring for 10 to 20 seconds, while the mixture thus formed is mixed for another 40 to 80 seconds. seconds, after which 155 to 220 kg of mixing water are sprayed for 40 to 60 seconds, or this amount of mixing water is sprayed on it for 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared, in which case at least 70% wt. aggregates made of recycled concrete. 47. A method for preparing fresh concrete according to claim 36, characterized in that in a forced circulation mixer, 820 kg to 1525 kg of recycled concrete is mixed for 20 to 40 seconds, which consists entirely or at least of the majority of concrete crumb or crumb from other cement-containing material, with a recycled fraction of 0 to 8 mm, after mixing it is added to it with constant stirring 350 to 600 kg of natural aggregate with an upper fraction up to 8 mm, and the mixture thus formed is mixed for 20 to 40 seconds, after mixing 28 to 52 kg of silica fume are added to it with constant stirring over a period of 10 to 15 seconds, the mixture thus formed is mixed for 40 to 80 seconds and, after mixing, 135 to 400 kg of cement are added to it with constant stirring over 10 to 20 seconds, the mixture thus formed is stirred for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed with stirring for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after a further 80 to Fresh concrete with at least 70% by weight is prepared for 160 seconds of mixing. aggregates made of recycled concrete. . Y. . PS4148CZ 42 ' 48. A method for preparing fresh concrete according to claim 47, characterized in that 1025 to 1320 kg of recycled concrete with a fraction of 0 to 8 mm are mixed in a forced circulation mixer for 20 to 40 seconds, after which it is added with constant stirring. 450 to 585 kg of natural aggregate, and the mixture thus formed is stirred for 20 to 40 seconds, after its mixing, 35 to 45 kg of silica fume is added to it with constant stirring for 10 to 15 seconds, the mixture thus formed is stirred for 40 to 80 seconds, and after mixing, 170 to 255 kg of cement are added to it with constant stirring over a period of 10 to 20 seconds, the mixture thus formed being mixed for another 40 to 80 seconds, after which 155 to 220 kg of mixing water are sprayed with constant stirring for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete with at least 70% by weight is prepared. aggregates made of recycled concrete. Process for the preparation of 1 m ^{3 of} fresh concrete according to any one of claims 1 to 3, characterized in that the recycled recycled inert construction demolition waste of the first composition is mixed for 20 to 40 seconds in a forced circulation mixer, after it has been mixed. After mixing, the recycle of inert construction demolition waste of the second composition is added and the mixture thus formed is mixed for 20 to 40 seconds, then natural aggregate is added and the mixture thus formed is stirred for another 20 to 40 seconds, then the mixture is added for 10 to 15 seconds. to 52 kg of silica fume, the mixture thus formed is mixed for 40 to 80 seconds and, after mixing, 135 to 400 kg of cement are added to it with constant stirring for 10 to 20 seconds, the mixture thus formed being mixed for another 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed with stirring for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, knows fresh concrete in which at least 70% of the aggregate is recycled from inert construction demolition waste. 50. A process for the preparation of 1 m ^{3 of} fresh concrete according to claim 1, characterized in that 1000 to 2000 kg of recycled material from inert construction demolition waste is mixed in a forced circulation mixer for 20 to 40 seconds, after which it is added with constant stirring. at least one. . . PS4148CZ 43 finishing admixture for improving the thermal and / or acoustic and / or fire-retardant properties of concrete in an amount of up to 30% by weight. of the total aggregate in the concrete, and the mixture thus formed is mixed for 20 to 40 seconds, then 28 to 52 kg of silica fume is added over a period of 10 to 15 seconds and the mixture thus formed is mixed for 40 to 80 seconds and after mixing. 135 to 400 kg of cement are added over a period of 10 to 20 seconds, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed or stirred for 40 to 60 seconds with constant stirring for 40 to 60 seconds. seconds spray this amount of mixing water, and after another 80 to 160 seconds of mixing, fresh concrete is prepared. 51. A process for the preparation of 1 m ^{3 of} fresh concrete according to claim 1, characterized in that the recycled recycled inert construction demolition waste of the first composition is mixed for 20 to 40 seconds in a forced circulation mixer, and the recycled recycled waste from the first composition is added thereto. inert construction demolition waste of the second composition or natural aggregate and the mixture thus formed is mixed for 20 to 40 seconds, after mixing at least one finishing admixture is added to it with constant mixing to improve the thermal and / or acoustic and / or fire properties of concrete, and thus the mixture formed is stirred for 20 to 40 seconds, then 28 to 52 kg of silica fume is added to it in 10 to 15 seconds, the mixture thus formed is stirred for 40 to 80 seconds and after mixing it is stirred for 10 to 20 seconds. 135 to 400 kg of cement are added, the mixture thus formed being mixed for a further 40 to 80 seconds, after which 135 to 250 kg of mixing water are sprayed with constant stirring for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared. 52. A process for the preparation of 1 m ^{3 of} fresh concrete according to claim 1, characterized in that the recycled recycled inert construction demolition waste of the first composition is mixed in a forced circulation mixer for 20 to 40 seconds, after which it is added with constant stirring. PS4148CZ recycled from inert construction demolition waste of the second composition and the mixture thus formed is mixed for 20 to 40 seconds, then natural aggregate is added to it and the mixture thus formed is mixed for another 20 to 40 seconds, after its mixing at least one finishing admixture to improve the thermal and / or acoustic and / or fire-retardant properties of the concrete, and the mixture thus formed is mixed for 20 to 40 seconds, then 28 to 52 kg of silica fume is added to it for 10 to 15 seconds, the mixture thus formed is mixed 40 to 80 seconds and, after mixing, 135 to 400 kg of cement are added to it with constant stirring over a period of 10 to 20 seconds, the mixture thus formed being mixed for a further 40 to 8 0 seconds, after which 135 to 250 kg of mixing water are sprayed with stirring for 40 to 60 seconds, or this amount of mixing water is sprayed on it within 40 to 60 seconds, and after another 80 to 160 seconds of mixing, fresh concrete is prepared. A method for preparing fresh concrete according to any one of claims 28 to 52, characterized in that the mixing water contains at least one admixture or a mixture of several admixtures for the concrete in an amount of up to 5% by weight. batches of cement. Process for the preparation of fresh concrete according to any one of claims 28 to 53, characterized in that the natural aggregate is mined and / or crushed natural aggregate of fraction 0 to 4 mm.