Lightweight concrete mixture

Abstract

- 33 - Abstract Lightweight concrete mixture comprising a biocarbon fine lightweight aggregate, the biocarbon fine lightweight aggregate having particle sizes in the range of 0 to 4 mm, preferably 0 to 2 mm, a particle size distribution with D50 5 in the range of 0.010 to 1.00 mm, preferably 0.012 to 0.60 mm, further preferred 0.015 to 0.08 mm, a particle density in the range of 0.20-1.80 g / cm³, preferably 0.40-0.60 g / cm³ and a random reflectance of at least 1.3 %, preferably at least 1.5 %, further preferred at least 1.8%, most preferred at least 2 %. 10 Fig. 1

Description

[0001] ecoLocked GmbH

[0002] P151546PC00

[0003] Lightweight concrete mixture

[0004] The invention relates to a lightweight concrete mixture, a flowable lightweight concrete mixture, a lightweight open porous structure concrete mixture and a method for producing them.

[0005] Lightweight concrete is used in various construction applications due to its reduced weight and improved thermal properties. Lightweight aggregates are used in such concrete and / or mortar formulations to achieve lower densities. Common lightweight aggregates are relatively expensive and have a high global warming potential (GWP).

[0006] An object of the invention is to provide improved lightweight concrete. According to a first aspect of the invention the object is achieved by a lightweight concrete mixture comprising a biocarbon fine lightweight aggregate, the biocarbon fine lightweight aggregate having particle sizes in the range of 0 to 4 mm, preferably 0 to 2 mm, a particle size distribution with D50 in the range of 0.010 to 1.00 mm, preferably 0.012 to 0.60 mm, further preferred 0.015 to 0.08 mm, a particle density in the range of 0.20-1.80 g / cm3, preferably 0.40-0.60 g / cm3and a random reflectance of at least 1.3 %, preferably at least 1.5 %, further preferred at least 1.8%, most preferred at least 2 %.

[0007] The invention is based on the recognition that a biocarbon showing these properties is in particular well suited as a lightweight fine aggregate in concrete mixtures and is able to replace at least partly common lightweight fine aggregates. The use of biocarbon instead of common lightweight fine aggregate leads to lower global warming potential, lower cost and as further benefit to lower thermal conductivity of the resulting concrete in comparison to concrete based on concrete mixtures with only common lightweight fine aggregates. This invention includes the recognition that biocarbon is a superior lightweight aggregate for concrete and mortar. The invention further comprises the recognition that a particle density in the range of 0.20-1.8 g / cm3together with particle sizes in the range of 0 to 4 mm and a particle size distribution with D50 in the range of 0.010 to 1.00 mm of a biocarbon for lightweight concrete mixture not only ensures consistency in the volumetric proportions of the mixture in comparison to a mixture with common lightweight fine aggregate but is also able to ensure that mechanical properties like strength, density, and workability of the concrete are maintained. This is further bolstered by the biocarbon having a random reflectance of at least 1.3 %, indicating high carbon stability and high percentage of inert carbon.

[0008] The preferred and further preferred ranges further enhance the described properties. Thus, with the biocarbon according to the invention lightweight concrete with augmented GWP but maintained strength and density class compared to lightweight concrete with common lightweight fine aggregate. As a result, the integrity and performance of the concrete mix are maintained.

[0009] Biocarbon, also known as biochar, is a biomass-derived carbon-rich and carbon- stable material produced through the thermal decomposition (e.g. pyrolysis) of biomass feedstocks at moderate temperatures. The resulting material, biocarbon, is far more stable than the biomass input feedstocks and can prevent the release of emissions for hundreds to thousands of years. The thermal decomposition processes can include, but are not limited to the following presented in Table 1 and any combinations thereof. A biocarbon lightweight aggregate may be derived from one source and comprise one specific biocarbon but may also be a mixture of different biocarbons, for example of different sources or as result of different processes.

[0010] Table 1: Thermal decomposition processes and parameters

[0011] In Table la certain physical properties of biocarbon and the related norm or method for their determination are listed. Table la: Physical properties of biocarbon and their relevant standards

[0012] As used in the present disclosure, "biocarbon" refers to the solid product from the thermochemical decomposition of biomass at moderate temperatures under oxygen-controlled conditions. The resulting solid product known as biocarbon or sometimes as biochar, is far more stable than the biomass input feedstocks and can prevent the release of emissions for hundreds to thousands of years. In one aspect, the biocarbon of the present disclosure contains a minimum of 20 wt.% of carbon based on the elemental composition of the entire biocarbon material measured according to DIN 51732 or ISO 16948:2015. In other aspects, the biocarbon contains a minimum of 30 wt.%, minimum of 40 wt.% measured according to DIN 51732 or ISO 16948:2015, minimum of 50 wt.% measured according to DIN 51732 or ISO 16948:2015, minimum of 60 wt.% measured according to DIN 51732 or ISO 16948:2015, minimum of 70 wt.% measured according to DIN 51732 or ISO 16948:2015, a minimum of 75 wt.% measured according to DIN 51732 or ISO 16948:2015, a minimum of 80 wt.% measured according to DIN 51732 or ISO 16948:2015, minimum of 85 wt.% measured according to DIN 51732 or ISO 16948:2015, a minimum of 90 wt.% measured according to DIN 51732 or ISO 16948:2015, or a minimum of 95 wt.% carbon based on the elemental composition of the entire biocarbon material measured according to DIN 51732 or ISO 16948:2015.

[0013] If not stated otherwise wt.% of biocarbon in this application refer to biocarbon with 18 wt.% moisture content. If biocarbon with higher or lower moisture content is used the ranges and values have to be adjusted accordingly. The biocarbon is preferably produced at a temperature of at least 450°C, which ensures the high random reflectance and thus high stability of the biocarbon and a high amount of inert carbon. Random reflectance (Ro) is a measurement of reflected white light, which is obtained on the surface of an organic carbon fragment under the microscope (ISO 7404-5, 2009) in an area of approximately 0.3 pm2. The Romeasurements is conducted on a perfectly polished surface to avoid any distortion caused by surface imperfections. There Romeasurements can be conducted in two modes, manual and automatic: (i) Manual Ro measurements are conducted on 500 randomly exposed macerals (exposed to the polished surface) within a biocarbon to ensure a significant representation of maceral diversity in the biocarbon samples. The values are expressed on a frequency distribution histogram to show the range of measured Rovalues in a single sample. The average (mean) of the 500 measured Rovalues is used to express the Roas a single number for the given samples. The quality of the mean Rodepends on the range / standard deviation of the measurements. A sample with a wide range of Rodistribution would have a large standard deviation and hence poor mean Rorepresentation, (ii) Automatic Rois preferably obtained by measuring Roon every single pixel of the entire sample under the microscope. It consists of millions of measurements and the Rodistribution presents quantitative representation of the carbon, namely the aromaticity and order of carbon structure and thus a good indication of the carbon's reactivity recalcitrance and / or permanence of the sample.

[0014] Common lightweight aggregate comprises or consists of natural lightweight aggregates (NLWA) and / or manufactured (Synthetic) lightweight aggregates (MLWA). In accordance with EN13055 a lightweight aggregate has a particle density < 2000 kg / m3and / or a bulk density < 1200 kg / m3.

[0015] Common lightweight fine aggregates within the meaning of this application are lightweight aggregates with a particle size below 2 mm. Common lightweight coarse aggregates within the meaning of this application are lightweight aggregates with a particle size of 2 mm or more and having unavoidable fine fraction below 10 weight percent, preferably below 5 weight percent of the lightweight aggregate weight. Natural lightweight aggregates are preferably selected from the group comprising or consist of pumice and scoria. Pumice is a volcanic rock that is light yet strong; scoria is another type of volcanic rock used for its light weight.

[0016] Manufactured (synthetic) lightweight aggregates are preferably selected from the group comprising or consisting of expanded shale, expanded clay, expanded slate, vermiculite, expanded vermiculite, expanded glass aggregate, foamed slag, perlite, expanded perlite, sintered fly ash, polystyrene, preferably expanded polystyrene and / or foamed polystyrene. Expanded Shale, Clay, and Slate (ESCS) can be produced by heating these materials to expand them. Foamed slag can be created by cooling molten slag rapidly with water. Expanded perlite is a volcanic glass that expands when heated. Sintered fly ash can be manufactured by sintering fly ash collected from thermal power plants. Polystyrene is a lightweight synthetic material often used in lightweight concrete. These materials are used in concrete according to the state of the art given their lightweight and adequate strength, making them suitable for various concrete applications and may conform to EN 13055.

[0017] In other words, the invention relates to the use of a biocarbon fine lightweight aggregate in lightweight concrete, the biocarbon fine lightweight aggregate having particle sizes in the range of 0 to 4 mm, preferably 0 to 2 mm, a particle size distribution with D50 in the range of 0.010 to 1.00 mm, preferably 0.012 to 0.60 mm, further preferred 0.015 to 0.08 mm, a particle density in the range of 0.20-1.80 g / cm3, preferably 0.40-0.60 g / cm3, further preferred 0.44-0.46 g / cm3and a random reflectance of at least 1.3 %, preferably at least 1.5 %, further preferred at least 1.8%, most preferred at least 2 %.

[0018] In a preferred embodiment, the lightweight concrete mixture is a flowable lightweight concrete mixture for density classes D1.0 to D2.0 and strength classes LC12 / 13 to LC25 / 28 and comprises the biocarbon fine lightweight aggregate as sole fine lightweight aggregate. In this embodiment, a flowable lightweight concrete mixture is achieved with the use of biocarbon and without commonly used lightweight fine aggregates. Thus, in this embodiment of the invention the concrete mixture does not comprise common lightweight fine aggregates. As used in the present disclosure, "flowable concrete" refers to all wet mix concrete that falls into a slump class or flow class according to the definition outlined in EN 206, "flowable lightweight concrete" refers to wet mix concrete falling under the respective definitions in terms of density and strength outlined in EN 206.

[0019] Preferably, the flowable lightweight concrete mixture comprises a flowable aggregate mixture, the flowable aggregate mixture comprising 1 to 40 wt.% of the biocarbon fine lightweight aggregate, 0 to 70 wt.% of a normal fine aggregate having particle sizes in the range of 0 to 2 mm and one common coarse aggregate having particle sizes in the range of 2 to 8 mm in a range of 35 to 80 wt.%, wherein the common coarse aggregate is either a common coarse lightweight aggregate or a common coarse normal aggregate. The use of biocarbon fine lightweight aggregate enables to eliminate common fine lightweight aggregate in the mixture and achieving the desired strength and density classes with an aggregate mixture of biocarbon fine lightweight aggregate, normal fine aggregate and common coarse lightweight aggregate or common coarse normal aggregate.

[0020] Normal fine or coarse aggregates are aggregates with higher densities than lightweight aggregates and are commonly used in concrete mixtures. Examples for common coarse normal aggregates are gravel or crushed rock, sand is a widely used normal fine aggregate.

[0021] Common lightweight fine aggregate, common coarse lightweight aggregate, normal fine aggregate and common coarse normal aggregate may consist of one material but may also be a respective mix of different materials.

[0022] In a further embodiment the lightweight concrete mixture is a flowable lightweight concrete mixture for density classes D1.0 to D1.4 and strength classes LC12 / 13 to LC16 / 18 wherein the flowable aggregate mixture comprises 35 to 80 wt.% common coarse lightweight aggregate. By modifying the biocarbon dose and the doses of the further aggregates in the mixture different density and strength classes of lightweight concrete can be realized. In an embodiment, the lightweight concrete mixture is a flowable concrete mixture for density class D1.0 and strength class LC 12 / 13, wherein the flowable aggregate mixture consists of the common coarse lightweight aggregate and the biocarbon fine lightweight aggregate, preferably of 70 to 80 wt.% of the common coarse lightweight aggregate and 20 to 30 wt.% of the biocarbon fine lightweight aggregate.

[0023] For density class DI.2 and strength class LC12 / 13, in an embodiment, the flowable aggregate mixture consists of 30 to 40 wt.% normal fine aggregate, 50 to 60 wt.% common coarse lightweight aggregate and 10 to 20 wt.% biocarbon lightweight aggregate. For density class DI.2 and strength class LC16 / 18, in an embodiment, the flowable aggregate mixture consists of 45 to 50 wt.% normal fine aggregate, 45 to 50 wt.% common coarse lightweight aggregate and 5 to 10 wt.% biocarbon lightweight aggregate. For density class D1.4 and strength class LC16 / 18, in an embodiment, the flowable aggregate mixture consists of 55 to 60 wt.% normal fine aggregate, 35 to 40 wt.% common coarse lightweight aggregate and 0.5 to 5 wt.% biocarbon lightweight aggregate.

[0024] In a further embodiment the lightweight concrete mixture is a flowable lightweight concrete mixture for density classes DI.6 to D2.0 and strength classes LC12 / 13 to LC25 / 28, wherein the flowable aggregate mixture comprises 35 to 50 wt.% of common coarse normal aggregate and 35 to 60 wt.% of normal fine aggregate and 3 to 20 wt.% of the biocarbon fine lightweight aggregate. The use of biocarbon lightweight aggregate enables the use of common coarse normal aggregate in the higher density classes and thus replacing also the common coarse lightweight aggregates. In the higher classes, the flowable lightweight concrete mixture thus does not comprise any common lightweight aggregate.

[0025] For density class DI.6 and strength class LC12 / 13, in an embodiment, the flowable aggregate mixture consists of 30 to 40 wt.% normal fine aggregate, 40 to 50 wt.% common coarse normal aggregate and 15 to 25 wt.% biocarbon lightweight aggregate. For density class DI.8 and strength class LC20 / 22, in an embodiment, the flowable aggregate mixture consists of 45 to 55 wt.% normal fine aggregate, 35 to 45 wt.% common coarse normal aggregate and 5 to 10 wt.% biocarbon lightweight aggregate. For density class D2.0 and strength class LC25 / 28, in an embodiment, the flowable aggregate mixture consists of 45 to 55 wt.% normal fine aggregate, 40 to 50wt.% common coarse normal aggregate and 1 to 6 wt.% biocarbon lightweight aggregate. Preferably the flowable lightweight concrete mixture further comprises at least one cement, water and preferably at least one supplementary cementitious material and / or at least one chemical admixture. As cement the following cement types according to EN 197-1, are preferred CEM I, CEM II, CEM III, CEM IV, CEM V, and CEM VI. Supplementary cementitious materials (SCMs) are materials that, when used in conjunction with Portland cement, contribute to the properties of the hardened concrete through hydraulic or pozzolanic activity. SCMs have a particle density of at least 2000 kg / m3, preferably in the range between 2000 and 3000 kg / m3. These materials include, but are not limited to, fly ash (in particular class F and / or C), silica fume, slag cement (ground granulated blast furnace slag), calcined clay, natural pozzolans, rice husk ash, bagasse ash and metakaolin. SCMs can be produced through various methods, such as high energetic mechanical processing, carbonation, and wet processing, and they are typically used to enhance the durability, strength, and sustainability of concrete. For the purpose of this invention preferred SCMs include but are not limited to the following:

[0026] Fly Ash: A byproduct of coal combustion in power plants. It enhances concrete's workability and strength and reduces permeability.

[0027] Silica Fume: A byproduct of silicon or ferrosilicon alloy production. It increases concrete's strength and durability.

[0028] Slag Cement (Ground Granulated Blast-Furnace Slag): A byproduct of iron production in blast furnaces. It improves concrete's strength, durability, and resistance to chemical attack.

[0029] Calcined Clay: Processed clay that reacts with cement to improve concrete's mechanical properties and durability.

[0030] Natural Pozzolans: Naturally occurring materials like volcanic ash, which react with calcium hydroxide to improve concrete properties.

[0031] Rice Husk Ash: A highly siliceous byproduct of rice milling, exhibiting pozzolanic activity by reacting with calcium hydroxide, improving concrete's strength, density, and resistance to chemical attack.

[0032] Bagasse Ash: Derived from the combustion of sugarcane residue (bagasse), acting as a pozzolanic material that contributes to concrete's compressive strength and durability.

[0033] Metakaolin: A high-reactivity pozzolan made by calcining kaolin clay. It enhances concrete's strength and reduces its permeability. Water used in concrete is a fundamental component necessary for the hydration of cement and the overall mixing process. For the purposes of this invention, the term "water" refers broadly to any type of water used in the concrete mix without specifying particular purity or chemical composition requirements.

[0034] One or more admixtures can be added to the lightweight concrete mixture to enhance its properties. These admixtures can improve the performance of the concrete. The one or more admixtures is / are selected from the group consisting of:

[0035] (bio)polymers selected from the group consisting of cellulose and derivatives thereof, starch and derivatives thereof, lignin and derivatives thereof, preferably lignin sulfonates, kraftlignins and lignin carboxylates, pectins and derivatives thereof, xanthan and derivates thereof, guarethers and derivatives thereof; chitin and derivatives thereof, algin and derivatives thereof, chitosan and derivatives thereof, cylcodextrins and derivatives thereof, dextrins and derivatives thereof; natural glues, hydrogel builders, plant lime, latex, rubber and derivatives thereof; proteins and peptides comprising one or more of the amino acids selected from the group consisting of alanin, glycin, lysin, asparagin, glutamin, glutamate and non- proteinogenic amino acids; industrial substances, residual polymeric substances and industrial byproducts selected from the group consisting of industrial effluents, preferably corn steep liquor, lactose mother liquor, protein lysates and molasses, vegetable meals, preferably corn gluten meal, pea meal, fruit meals and protein wastes, preferably from yeast production, meat production, fruit production, vegetable production, egg production, dairy industry and papermaking; starch ethers, starch esters, starch carboxylates, cellulose esters, cellulose ethers, cellulose carboxylates, yeasts and derivatives or extracts thereof; liquid or dried polymer dispersions or polymers comprising organic acids, preferably sulfonic acids, carboxylic acids, peroxy carboxylic acids and thio carboxylic acids and salts thereof, sulfoxides, cyanates, thiocyanates, esters, ethers, thio ethers, oxides, thio oxides, amines, imines, hydrazines, hyrazones, amids, sulfates, nitriles, aldehydes, thio aldehydes, ketons, thioketons, oximes, alkohols, thiols, radicals, halogens, silanes, siloxanes, phosphates, phosponates, alkyls, allyls, aryls and derivatives thereof, wherein preferably the polymer(s) is / are biodegradable;

[0036] (poly)saccharides, extracellular substances and derivatives thereof selected from the group consisting of (poly)saccarides comprising lactose, glucose, fructose, saccharose and / or galactose, and microbial exopolysaccharides, preferably comprising lactose, saccharose, glucose, glucosamine, mannose, glycerin, gluconate, fructose and / or inulin; organic acids and derivatives thereof, preferably selected from the group consisting of monocarboxylic acids, preferably formic acid, acetic acid, propionic acid, butyric acid, benzoic acid and salicylic acid, dicarboxylic acids, preferably oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and maleic acid, fatty acids, keto acids, preferably pyruvic acid and acetoacetic acid, fruit acids, preferably malic acid and tartaric acid, hydroxy acids, preferably lactic acid, alpha hydroxy acids and beta hydroxy acids, tricarboxylic acids, preferably citric acid, more preferably carboxylates and esters of the before mentioned; amino acids and derivatives thereof, preferably selected from the group consisting of alanin, glycine, lysine, glutamine, glutamate, and non- proteinogenic amino acids, preferably esters and amides thereof; substances changing the reaction mechanism, preferably retarders, accelerators, bleeding modifiers, hydrophilizers, hydrophobizers, air entraining agents, viscosity modifiers, 10 expanders, accelerators, retarders, thickeners, plasticizers, superplasticizers, seeding materials and nanoparticle seeding materials.

[0037] It is further preferred, that the flowable lightweight concrete mixture comprises gravel, silt and / or sand as normal fine aggregate. These normal fine aggregates have a particle size in the range of 0 mm to 2mm and may further include fines; they further preferably conform to EN 12620.

[0038] In preferred embodiments of the flowable lightweight concrete mixture the preferred cement content is between 250-450 kg / m3, preferably between 260- 430 kg / m3, preferably between 270-410 kg / m3, preferably between 280-390 kg / m3, preferably between 290-370 kg / m3, preferably between 300-350 kg / m3, preferably between 310-330 kg / m3, preferably between 315-325 kg / m3. In preferred embodiments of the flowable lightweight concrete mixture the SCM content is between 0-150 kg / m3, preferably between 20-140 kg / m3, preferably between 40-130 kg / m3, preferably between 60-120 kg / m3, preferably between 80-100 kg / m3, preferably between 90-105 kg / m3. ln preferred embodiments of the flowable lightweight concrete mixture the common lightweight coarse aggregate content is between 0-400 kg / m3, preferably between 50-395 kg / m3, preferably between 100-390 kg / m3, preferably between 150-385 kg / m3, 200-380 kg / m3, preferably between 220- 375 kg / m3, preferably between 240-370 kg / m3, preferably between 260-365 kg / m3, preferably between 280-360 kg / m3, preferably between 300-355 kg / m3, preferably between 320-350 kg / m3, preferably between 340-348 kg / m3.

[0039] In preferred embodiments of the flowable lightweight concrete mixture the sand content is between 0-450 kg / m3, preferably between 50-440 kg / m3, preferably between 100-430 kg / m3, preferably between 150-420 kg / m3, preferably between 200-410 kg / m3, preferably between 250-400 kg / m3, preferably between 280-390 kg / m3, preferably between 300-380 kg / m3, preferably between 320-370 kg / m3, preferably between 330-365 kg / m3, preferably between 340-360 kg / m3, preferably between 350-358 kg / m3.

[0040] In preferred embodiments of the flowable lightweight concrete mixture the biocarbon fine lightweight aggregate content is between 20-150 kg / m3, preferably between 25-140 kg / m3, preferably between 30-130 kg / m3, preferably between 35-120 kg / m3, preferably between 40-110 kg / m3, preferably between 41-105 kg / m3

[0041] It is also possible to include additionally a biocarbon coarse fraction, of which the content is between 0-350 kg / m3, preferably between 25-300 kg / m3, preferably between 50-200 kg / m3.

[0042] In preferred embodiments of the flowable lightweight concrete mixture the water content is between 150-350 kg / m3, preferably between 160-340 kg / m3, preferably between 170-330 kg / m3, preferably between 180-320 kg / m3, preferably between 190-310 kg / m3, preferably between 200-305 kg / m3, preferably between 210-300 kg / m3, preferably between 220-295 kg / m3. In preferred embodiments of the flowable lightweight concrete mixture the admixture content is between 0.0-10.0 kg / m3, preferably between 0.5-5.0 kg / m3, preferably between 1.0-3.0 kg / m.

[0043] The lightweight concrete mixture may be a lightweight open porous structure concrete mixture for density classes DI.2 to DI.4 and strength classes LCA6 to LCA8 and comprising the biocarbon fine lightweight aggregate. In lightweight open porous structure concrete mixtures, it is preferred that a porous aggregate mixture comprising common fine lightweight aggregate and biocarbon fine lightweight aggregate is used. Thus, herein the amount of common fine lightweight aggregate is reduced in comparison to common lightweight open porous structure concrete mixtures. Also here the use of biocarbon reduces the global warming potential while maintaining the performance of the concrete mixture in comparison to the common lightweight open porous structure concrete mixture.

[0044] As used in the present disclosure, "open porous structure" refers to all open porous structure concrete that falls into a strength and density class according to the definition outlined in EN 1520. Open porous structure is typically concrete with a deliberately discontinuous pore structure, allowing air and moisture to pass through, achieved by controlled aggregate grading.

[0045] Porous aggregate mixture herein means that this aggregate mixture is suitable for a lightweight open porous structure concrete mixture and does not imply that the aggregate mixture itself or its parts are necessarily porous.

[0046] The lightweight open porous structure concrete mixture may comprise a porous aggregate mixture, wherein the porous aggregate mixture comprises 2 to 5 wt.% of the biocarbon fine lightweight aggregate, 20 to 45 wt.% of a common medium lightweight aggregate having particle sizes in the range of 0.5 to 8 mm, 35 to 65 wt.% of a normal fine aggregate having particle sizes in the range of 0 to 2 mm and one normal common coarse aggregate having particle sizes in the range of 2 to 8 mm in a range of 5 to 25 wt.%, preferably 10 to 20 wt.%. Common medium lightweight aggregate means that this aggregate has fine and coarse particles reflected in the particle sizes in the range of 0.5 to 8 mm. Thus common medium lightweight aggregate may also be replaced by a mixture of a common fine lightweight aggregate (with particle sizes of 0.5 to 2 mm) and common coarse lightweight aggregate building together the common medium lightweight aggregate.

[0047] It is preferred if the porous aggregate mixture comprises 2 to 4 wt.% of the biocarbon fine lightweight aggregate, 22 to 41 wt.% of the common medium lightweight aggregate, 41 to 58 wt.% of the normal fine aggregate and the normal common coarse aggregate in a range of 13 to 19 wt.%.

[0048] The lightweight concrete mixture may be a lightweight open porous structure concrete mixture for density class DI.2 and strength classes LCA6, wherein the porous aggregate mixture comprises 2 to 5 wt.%, preferably 3 to 4 wt.%, of the biocarbon fine lightweight aggregate, 35 to 45 wt.%, preferably 37 to 41 wt.%, of the common medium lightweight aggregate, 38 to 48 wt.%, preferably 41 to 43 wt.% of the normal fine aggregate and the normal common coarse aggregate in a range of 10 to 20 wt.%, preferably 13 to 17 wt.%.

[0049] In a further embodiment the lightweight concrete mixture is a lightweight open porous structure concrete mixture for density class DI.4 and strength classes LCA6 to LCA8, wherein the porous aggregate mixture comprises 2 to 5 wt.%, preferably 2 to 3 wt.%, of the biocarbon fine lightweight aggregate, 20 to 30 wt.%, preferably 22 to 25 wt.%, of the common medium lightweight aggregate, 52 to 62 wt.%, preferably 56 to 58 wt.% of the normal fine aggregate and the normal common coarse aggregate in a range of 10 to 20 wt.%, preferably 16 to 19 wt.%.

[0050] It is further preferred if the lightweight open porous structure concrete mixture further comprises at least one cement, water and optionally at least one supplementary cementitious material and / or at least one chemical admixture.

[0051] It is further preferred, that the lightweight open porous structure concrete mixture comprises gravel, silt and / or sand as normal fine aggregate. These normal fine aggregates have a particle size in the range of 0 mm to 2mm and may further include fines; they further preferably conform to EN 12620. In preferred embodiments of the lightweight open porous structure concrete mixture the preferred cement content is between 250-350 kg / m3, preferably between 250-330 kg / m3, preferably between 270-310 kg / m3.

[0052] In preferred embodiments of the lightweight open porous structure concrete mixture, optionally the SCM content is between 0-150 kg / m3, preferably between 20-140 kg / m3, preferably between 40-130 kg / m3, preferably between 60-120 kg / m3, preferably between 80-100 kg / m3, preferably between 90-105 kg / m3.

[0053] In preferred embodiments of the lightweight open porous structure concrete mixture the common lightweight medium aggregate content is between 0-400 kg / m3, preferably between 50-395 kg / m3, preferably between 100-390 kg / m3, preferably between 150-385 kg / m3, 200-380 kg / m3, preferably between 220- 375 kg / m3, preferably between 240-370 kg / m3, preferably between 260-365 kg / m3, preferably between 270-360 kg / m3, preferably between 250-355 kg / m3, preferably between 240-350 kg / m3, preferably between 230-348 kg / m3.

[0054] In preferred embodiments of the lightweight open porous structure concrete mixture the sand content is between 0-700 kg / m3, preferably between 50-650 kg / m3, preferably between 100-645 kg / m3, preferably between 150-640 kg / m3, preferably between 200-635 kg / m3, preferably between 250-630 kg / m3, preferably between 300-625 kg / m3, preferably between 330-620 kg / m3, preferably between 340-615 kg / m3.

[0055] In preferred embodiments of the lightweight open porous structure concrete mixture the biocarbon fine lightweight aggregate content is between 2-150 kg / m3, preferably between 5-140 kg / m3, preferably between 10-130 kg / m3, preferably between 15-120 kg / m3, preferably between 20-110 kg / m3, preferably between 41-105 kg / m3, preferably between 25-100 kg / m3.

[0056] It is also possible to include additionally a biocarbon coarse fraction, of which the content is between 0-350 kg / m3, preferably between 25-300 kg / m3, preferably between 50-200 kg / m3. In preferred embodiments of the lightweight open porous structure concrete mixture the water content between 90-250 kg / m3, preferably between 100-200 kg / m3, preferably between 105-180 kg / m3, preferably between 110-160 kg / m3, preferably between 115-150 kg / m3, preferably between 110-145 kg / m3.

[0057] In preferred embodiments of the lightweight open porous structure concrete mixture, optionally the admixture content between 0.0-10.0 kg / m3, preferably between 0.5-5.0 kg / m3, preferably between 1.0-3.0 kg / m.

[0058] According to a second aspect the invention relates to a method for producing a lightweight concrete mixture, preferably a lightweight concrete mixture according to the first aspect of the invention, comprising producing a biocarbon at a process temperature of at least 450 °C and with a particle density in the range of 0.20-1.80 g / cm3, preferably 0.40-0.60 g / cm3, treating the biocarbon preferably via milling and / or sieving to a biocarbon fine lightweight aggregate having particle sizes in the range of O to 4 mm, preferably O to 2 mm, a particle size distribution with D50 in the range of 0.01 to 1. 00 mm, preferably 0.012 to 0.60 mm, further preferred 0.015 to 0.08 mm, mixing the biocarbon fine lightweight aggregate with common fine lightweight aggregate and / or common coarse lightweight aggregate and / or common medium lightweight aggregate and / or normal fine aggregate and / or common coarse normal aggregate to build a flowable or porous aggregate mixture.

[0059] In an embodiment the method further comprises mixing the flowable or porous aggregate mixture with at least one cement, water and preferably at least one supplementary cementitious material and / or at least one chemical admixture.

[0060] The biocarbon is preferably produced at a process temperature of at least 450°C resulting in a random reflectance of at least 1.3 %, more preferably 1.5 %, even more preferred 1.8 %. In a preferred embodiment the biocarbon is produced at a process temperature of at least 550°C, preferably resulting in a random reflectance of at least 2.0 %.

[0061] The method may comprise processing and / or treating at least parts of at least one biocarbon to a biocarbon fine lightweight aggregate having a median particle size range of 0.001 to 0.080 mm and / or with a median particle size of 0.046 mm, in particular containing 99% of particles finer than 2.000 mm, 97% of particles finer than 1.000 mm, 87% of particles finer than 0.500mm, 72% of particles finer than 0.200 mm, 64% of particles finer than 0.100 mm, 58% of particles finer than 0.063 mm, and 32% of particles finer than 0.025 mm.

[0062] The method may further comprise transporting the biocarbon fine lightweight aggregate to a first location of concrete mixing and / or processing, and / or using the biocarbon fine lightweight aggregate in a lightweight open porous structure or a flowable lightweight concrete.

[0063] The method may comprise in an embodiment determining a set of parameters for processing the at least one biocarbon and / or the concrete mixture based on a biocarbon water correction factor (BWCF) of the at least one biocarbon, which is defined as a percentage of a water absorption of the at least one biocarbon, wherein the biocarbon water correction factor is preferably in a range of 10 to 100 % of the water absorption of the at least one biocarbon.

[0064] The biocarbon water correction factor BWCF is in other words the product of a percentage, namely the biocarbon water correction percentage BWCP, and the water absorption WA of the at least one biocarbon, thus BWCF = BWCP * WA. The biocarbon water correction factor multiplied with the dry weight of the at least one biocarbon in the mixture gives the weight of an amount of waterto add into the concrete mixture to compensate the presence of the biocarbon. Thus the biocarbon water correction factor indicates an amount of waterto add into the concrete mixture to compensate the presence of the biocarbon as percentage of the weight of the biocarbon.

[0065] The water absorption is given in mass percent and gives the weight of water absorbed by the respective water saturated and surface dry biocarbon per selfweight of the dry biocarbon and can be determined according to EN 13055. The method may comprise the step of determining a water absorption of the at least one biocarbon before determining the set of parameters, wherein the water absorption is preferably determined by measuring or calculating or estimating taking into account a water holding capacity, a water content, a median particle size and / or particle density of the at least one biocarbon. In an embodiment the set of parameters comprises at least one selected from the group consisting of: selection of at least one biocarbon from a group of possible biocarbons for the concrete mixture; required median particle size, required water content of the at least one biocarbon before adding to the concrete mixture process parameters for an adjustment of the median particle size, process parameters for a pre-wetting of the at least one biocarbon, dose of the selected at least one biocarbon, required total amount of added water, required amount of added water during mixing the concrete mixture, required amount and type of added cement, required amount and type of at least one additive, required amount and type of at least one plasticizer, preferably of at least one superplasticizer, aggregate replacement ratio, a corrected water-cement ratio, order of addition.

[0066] It is preferred if the corrected water-cement ratio is determined as ( wherein BWCF is the biocarbon water correction factor, ( — ) is a targeted water-cement ratio for a reference concrete mixture \c / 1without biocarbon, mbiocarbonis the mass of biocarbon in the concrete mixture and wtis a targeted water amount for the reference concrete mixture without biocarbon and / or if the corrected water-cement ratio is determined as(— )corr= ( — I ■ (1 + c wherein BWCF is the biocarbon water correction factor, targeted water-cement ratio for a reference concrete mixture without biocarbon, mbiocarbonis the mass of biocarbon in the concrete mixture and ctis a targeted cement amount for the reference concrete mixture without biocarbon and / or if the required total amount of water is determined as wtotai =wt + BWCF ■ mbiocarbon, wherein BWCF is the biocarbon water correction factor, wtis a targeted water amount according to the targeted water-cement ratio for the reference concrete mixture without biocarbon (— ) and mbiocarbonis the mass of biocarbon in the concrete \c / tmixture and / or if the required amount of cement is determined as c =(Wt + B WCB mbio carbon) (~^)corr wherein BWCF is the biocarbon water correction factor, (— ) is the corrected water-cement ratio, m.biocarbonis the mass of biocarbon in the concrete mixture and wtis a targeted water amount for the reference concrete mixture without biocarbon and / or if the required total amount of water is determined as a sum of a water content added during pre-wetting the biocarbon and an added water amount during mixing the concrete mixture and / or if the order of addition comprises providing common lightweight coarse aggregates, adding 100% of the selected at least one biocarbon to the common lightweight coarse aggregates, adding at least the amount of water according to the biocarbon water correction factor to the mix of at least one biocarbon and aggregates, adding cement, adding water up to the total amount of water, optionally adding at least one plasticizer, preferably at least one superplasticizer.

[0067] Determining the set of parameters comprises preferably using at least one further material property of the at least one biocarbon, the at least one further material property comprise at least one of carbon content, ash content, oxide content, random reflectance, surface morphology and surface charge, water content (%) (partial or water full saturation), particle size distribution, median particle size, particle size and shape and specific surface area.

[0068] Determining the set of parameters preferably additionally comprises using at least one performance parameter of at least one known concrete mixture, wherein the at least one performance parameter comprises mechanical strength performance comprising 24 h, 7 and 28 day compressive and / or flexural strength and / or concrete rheological performance comprising workability and / or flowability and / or slump retention and / or flow diameter retention and / or thermal conductivity and / or fresh density and / or dry density and / or setting time and / or capillary porosity and / or permeability and / or long-term stability and / or carbonation and / or freeze thaw resistance and / or air content and / or fire / heat resistance and / or shrinkage.

[0069] The method preferably comprises at least one of the following processing steps: selecting at least one biocarbon of the group of possible biocarbons for adding into the concrete mixture and / or treating the at least one biocarbon preferably via at least pre-wetting and / or adjustment of the median particle size and / or dosing the at least one biocarbon and / or adding water and / or adding cement and / or adding at least one additive, in particular at least one plasticizer, in particular at least one superplasticizer.

[0070] Preferably water and / or cement is added into the concrete mixture based on the biocarbon water correction factor, preferably with the biocarbon water correction factor being in the range of 10 to 100 % of the water absorption.

[0071] It is further preferred if water and / or cement is added into the concrete mixture according to the corrected water-cement ratio (—)corr= (— ) ■ (1 + c \ c jti i i • i • r wherein BWCF is the biocarbon water correction factor, a targeted water-cement ratio for a reference concrete mixture without biocarbon, mbjocari)onis the mass of biocarbon in the concrete mixture and wtis a targeted water amount for the reference concrete mixture without biocarbon and / or

[0072] .. . . . according to wherein BWCF is the biocarbon water correction factor, ( — ) is a targeted water-cement ratio for a \c / treference concrete mixture without biocarbon, mbiocarbonis the mass of biocarbon in the concrete mixture and ctis a targeted cement amount for the reference concrete mixture without biocarbon and / or according to wtotal= wt+ BWCF ■ mbiocarbon, wherein BWCF is the biocarbon water correction factor, wtis a targeted water amount according to the targeted water-cement ratio for the reference concrete mixture without biocarbon ( — ) and mbiocarbonis the mass of biocarbon in the concrete mixture \c / tand / or according to c =Wt + BWCB mbiocarbon)wherejnBWCF is the biocarbon water (~^)corr the corrected water-cement ratio, mb io carb onis the mass of biocarbon in the concrete mixture and wtis a targeted water amount for the reference concrete mixture without biocarbon and / or wherein the required total amount of water is a sum of a water content added during pre-weting the biocarbon and an added water amount during mixing the concrete mixture.

[0073] Preferably the at least one biocarbon is pre-wetted to a water content of 10 - 100 % of the water absorption of the at least one biocarbon, preferably prewetted to a water content in the range of 10 - 75, more preferred in the range of 10 - 50 %.

[0074] Preferably the order of addition is providing common lightweight coarse aggregates, adding 100% of the at least one biocarbon to the common lightweight coarse aggregates, adding at least the amount of water according to the biocarbon water correction factor to the mix of at least one biocarbon and aggregates, adding cement, adding water up to the total amount of water, optionally adding at least one plasticizer, preferably at least one superplasticizer.

[0075] In an embodiment at least one additive, comprising preferably a plasticizer, more preferred a superplasticizer, is added into the concrete mixture according , (?) ■“-> to the additive w / c optimization parameter XADwc= — - * 100 , -biocarbon the corrected water-cement ratio, cADis a dose of additive in weight-% of a cement content, dbiocarbonis the dosage of biocarbon in kg / m3, XADwcbeing in the range of 2.50 to 0.30, preferably between 2.0 and 0.4, more preferably between 1.44 and 0.45 and / or wherein a polycarboxylate (PCE) based superplasticizer, preferably in a dose of 0.2 to 3.0 %, more preferred 0.4 to 1.2 %, is added to the concrete mixture and / or wherein a lignosulfonate based superplasticizer preferably in a range of 0.2 to 1.5 %, more preferred 0.3 to 1.1 %, is added to the concrete mixture.

[0076] Embodiments of flowable lightweight concrete mixtures are described in the following and shown in the following tables. Table 1 exemplifies good mix quantity ranges for a flowable lightweight concrete containing biocarbon.

[0077] Table 1

[0078] Beside the biocarbon fine lightweight aggregate it is also possible to include additionally biocarbon coarse lightweight aggregate having particle sizes between 4 and 8 mm. It is then preferred if the weight ratio between biocarbon fine and coarse lightweight aggregate and common lightweight coarse aggregate is [m(biocarbon(fine and coarse fraction)) / m(common lightweight coarse aggregate)] is below 100000, preferably below 10000, preferably below 5000, preferably below 2500, preferably below 1000, preferably below 800, preferably below 600, preferably below 400, preferably below 300, preferably below 200, preferably below 100, preferably below 75, preferably below 50, preferably below 25, preferably below 20, preferably below 15, preferably below 10, preferably below 9, preferably below 8, preferably below 7, preferably below 6, preferably below 5, preferably below 4, preferably below

[0079] 3, preferably below 2, preferably below 1.5.

[0080] Table 2 exemplifies mix proportions of a mix for a flowable lightweight concrete mix containing biocarbon fine lightweight aggregate for density class DI.2. This mix is referred to from here on by the designation MOI.

[0081] Table 2

[0082] Table 3 exemplifies the mix proportions of mix for a flowable lightweight concrete mix containing biocarbon fine lightweight aggregate for density class

[0083] D1.0. This mix is referred to from here on by the designation M02.

[0084] Table 3

[0085] Compressive strength, fresh density and dry density measurements of the concrete mixes were done according to EN 12390-3, EN 12350-6, and EN 12390- 7, respectively. The thermal conductivity measurements were determined in accordance with dynamic measurement method, and / or plate method according to EN 12667.

[0086] The compressive strength results at 7 and 28 days of MOI and M02 are presented in Table 4.

[0087] Table 4

[0088] The measured fresh density of the concrete mix MOI is 1325 kg / m3and MOI achieved a dry density of 1190 kg / m3 after 28 days, which meets the target specification for DI.2. The measured thermal conductivity of this flowable lightweight concrete mixture was 0.394 W / (m.K). The developed MOI flowable lightweight concrete mix meets the specified requirements for compressive strength class LC12 / 13 and density class DI.2. The use of biocarbon contributed to the improved density while maintaining strength. With a range of biocarbon content from 41 to 75 kg / m3, the density class of DI.2 in this mix design can be achieved.

[0089] The measured fresh density of the concrete mix M02 was 1160 kg / m3and achieved a dry density of 950 kg / m3 after 28 days, which meets the target specification for D1.0. The measured thermal conductivity of this mix design was 0.208 W / (m.K).

[0090] The developed M02 lightweight concrete mix meets the specified requirements for compressive strength class LC12 / 13 and density class D1.0. The use of biocarbon contributed to improved density while maintaining strength. With a range of biocarbon content from 76 to 150 kg / m3, the density class of D1.0 can be achieved.

[0091] Embodiments of lightweight open porous structure concrete mixtures are described in the following and shown in the following tables. Table 5 exemplifies a good mix for a lightweight open porous structure concrete mixture containing biocarbon having DI.2 and a strength of 6.27 MPa.

[0092] Table 5 - T1 -

[0093] Table 6 exemplifies a good mix for a lightweight open porous structure concrete mixture containing biocarbon having D1.4 and a strength of 8.22 MPa.

[0094] Table 6

[0095] Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

[0096] In the drawings:

[0097] Fig. 1 is a schematic drawing of a method according to the invention.

[0098] Fig. 1 shows in a schematic drawing of an embodiment of a method for producing a lightweight concrete mixture according to the second aspect of the invention. The method is preferably method for producing a lightweight concrete mixture according to the first aspect of the invention. The method comprises as first step SI producing a biocarbon at a process temperature of at least 450 °C and with a particle density in the range of 0.2-1.8 g / cm3, preferably 0.40-0.60 g / cm3, further preferred 0.44-0.46 g / cm3. Producing the biocarbon at a process temperature of at least 450°C results in a random reflectance of at least 1.3 %. Further preferred a random reflectance of at least 1.5 %, even more preferred at least 1.8 % is adjusted. In other embodiments the biocarbon is produced at a process temperature of at least 550°C, which preferably results in a random reflectance of at least 2.0 %. In step 2 the biocarbon is treated to a biocarbon fine lightweight aggregate having particle sizes in the range of 0 to 4 mm and a particle size distribution with D50 in the range of 0.010 to 1. 00 mm. It is further preferred if the biocarbon is treated to a biocarbon fine lightweight aggregate having particle sizes in the range of 0 to 2 mm and a particle size distribution with D50 in the range of 0.012 to 0.60 mm, further preferred 0.015 to 0.08 mm. The treating is preferably performed via milling and sieving. In step S3 the biocarbon fine lightweight aggregate is mixed with common fine lightweight aggregate and / or common coarse lightweight aggregate and / or common medium lightweight aggregate and / or normal fine aggregate and / or common coarse normal aggregate to build a flowable or porous aggregate mixture. In particular, it is preferred if for a flowable aggregate mixture the biocarbon fine lightweight aggregate is mixed with only common coarse lightweight aggregate and / or normal fine aggregate and / or common coarse normal aggregate, whereby for a porous aggregate mixture and / or common medium lightweight aggregate comprising also fine particles is added.

[0099] Optionally the flowable or porous aggregate mixture is further mixed with at least one cement, water and preferably at least one supplementary cementitious material and / or at least one chemical admixture in step S4.

Claims

ecoLocked GmbHP151546PC00Claims1. Lightweight concrete mixture comprising a biocarbon fine lightweight aggregate, the biocarbon fine lightweight aggregate having particle sizes in the range of O to 4 mm, preferably O to 2 mm, a particle size distribution with D50 in the range of 0.010 to 1.00 mm, preferably 0.012 to 0.60 mm, further preferred 0.015 to 0.08 mm, a particle density in the range of 0.20-1.80 g / cm3, preferably 0.40-0.60 g / cm3and a random reflectance of at least 1.3 %, preferably at least 1.5 %, further preferred at least 1.8%, most preferred at least 2 %.

2. Lightweight concrete mixture according to claim 1, the lightweight concrete mixture being a flowable lightweight concrete mixture for density classes D1.0 to D2.0 and strength classes LC12 / 13 to LC25 / 28 and comprising the biocarbon fine lightweight aggregate as sole fine lightweight aggregate.

3. Lightweight concrete mixture according to claim 2, comprising a flowable aggregate mixture, the flowable aggregate mixture comprising 1 to 40 wt.% of the biocarbon fine lightweight aggregate, 0 to 70 wt.% of a normal fine aggregate having particle sizes in the range of 0 to 2 mm and one common coarse aggregate having particle sizes in the range of 2 to 8 mm in a range of 35 to 80 wt.%, wherein the common coarse aggregate is either a common coarse lightweight aggregate or a common coarse normal aggregate.

4. Lightweight concrete mixture for density classes D1.0 to DI.4 and strength classes LC12 / 13 to LC16 / 18 according to claim 3, wherein theflowable aggregate mixture comprises 35 to 80 wt.% common coarse lightweight aggregate.

5. Lightweight concrete mixture for density class D1.0 and strength class LC 12 / 13 according to claim 2 or 3, wherein the flowable aggregate mixture consists of the common coarse lightweight aggregate and the biocarbon fine lightweight aggregate, preferably of 70 to 80 wt.% of the common coarse lightweight aggregate and 20 to 30 wt.% of the biocarbon fine lightweight aggregate.

6. Lightweight concrete mixture for density classes DI.6 to D2.0 and strength classes LC12 / 13 to LC25 / 28 according to claim 3, wherein the flowable aggregate mixture comprises 35 to 50 wt.% of common coarse normal aggregate and 35 to 60 wt.% of normal fine aggregate and 3 to 20 wt.% of the biocarbon fine lightweight aggregate.

7. Lightweight concrete mixture according to any of claims 2 to 6 further comprising at least one cement, water and preferably at least one supplementary cementitious material and / or at least one chemical admixture.

8. Lightweight concrete mixture according to any of claims 2 to 7, wherein the normal fine aggregate comprise gravel, silt and / or sand.

9. Lightweight concrete mixture according to claim 1, the lightweight concrete mixture being a lightweight open porous structure concrete mixture for density classes DI.2 to D1.4 and strength classes LCA6 to LCA8 and comprising the biocarbon fine lightweight aggregate.

10. Lightweight concrete mixture according to claim 9 comprising a porous aggregate mixture, wherein the porous aggregate mixture comprises 2 to 5 wt% of the biocarbon fine lightweight aggregate, 20 to 45 wt.% of a common medium lightweight aggregate having particle sizes in the range of 0.5 to 8 mm, 38 to 62 wt.% of a normal fine aggregate having particle sizes in the range of 0 to 2 mm and one normal common coarse aggregate having particle sizes in the range of 2 to 8 mm in a range of 10 to 20 wt.%,.

11. Lightweight concrete mixture according to claim 10, wherein the porous aggregate mixture comprises 2 to 4 wt% of the biocarbon fine lightweight aggregate, 22 to 41 wt.% of the common medium lightweight aggregate, 41 to 58 wt.% of the normal fine aggregate and the normal common coarse aggregate in a range of 13 to 19 wt.%.

12. Lightweight concrete mixture for density class DI.2 and strength classes LCA6 according to claim 10, wherein the porous aggregate mixture comprises 2 to 5 wt.%, preferably 3 to 4 wt.%, of the biocarbon fine lightweight aggregate, 35 to 45 wt.%, preferably 37 to 41 wt.%, of the common medium lightweight aggregate, 38 to 48 wt.%, preferably 41 to 43 wt.% of the normal fine aggregate and the normal common coarse aggregate in a range of 10 to 20 wt.%, preferably 13 to 17 wt.%.

13. Lightweight concrete mixture for density class DI.4 and strength classes LCA6 to LCA8 according to claim 10, wherein the porous aggregate mixture comprises 2 to 5 wt.%, preferably 2 to 3 wt.%, of the biocarbon fine lightweight aggregate, 20 to 30 wt.%, preferably 22 to 25 wt.%, of the common medium lightweight aggregate, 52 to 62 wt.%, preferably 56 to 58 wt.% of the normal fine aggregate and the normal common coarse aggregate in a range of 10 to 20 wt.%, preferably 16 to 19 wt.%.

14. Lightweight concrete mixture according to any of claims 9 to 13 further comprising at least one cement, water and preferably at least one supplementary cementitious material and / or at least one chemical admixture.

15. Lightweight concrete mixture according to any of claims 9 to 14, wherein the normal fine aggregate comprise gravel, silt and / or sand.

16. Method for producing a lightweight concrete mixture, preferably a lightweight concrete mixture according to any of the preceding claims comprising producing a biocarbon at a process temperature of at least 450 °C and with a particle density in the range of 0.20-1.80 g / cm3, preferably 0.40-0.60 g / cm3,treating the biocarbon preferably via milling and / or sieving to a biocarbon fine lightweight aggregate having particle sizes in the range of O to 4 mm, preferably O to 2 mm, a particle size distribution with D50 in the range of 0.010 to 1.00 mm, preferably 0.012 to 0.60 mm, further preferred0.015 to 0.08 mm mixing the biocarbon fine lightweight aggregate with common fine lightweight aggregate and / or common coarse lightweight aggregate and / or common medium lightweight aggregate and / or normal fine aggregate and / or common coarse normal aggregate to build a flowable or porous aggregate mixture.

17. Method according to claim 16 further comprising mixing the flowable or porous aggregate mixture with at least one cement, water and preferably at least one supplementary cementitious material and / or at least one chemical admixture.

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