Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B7/00—Hydraulic cements
  • C04B7/24—Cements from oil shales, residues or waste other than slag
  • C04B7/246—Cements from oil shales, residues or waste other than slag from waste building materials, e.g. waste asbestos-cement products, demolition waste
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
  • C04B18/04—Waste materials; Refuse
  • C04B18/14—Waste materials; Refuse from metallurgical processes
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
  • C04B18/04—Waste materials; Refuse
  • C04B18/16—Waste materials; Refuse from building or ceramic industry
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
  • C04B28/04—Portland cements
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/58—Construction or demolition [C&D] waste
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/91—Use of waste materials as fillers for mortars or concrete

Definitions

• the present invention relates to blended cement which contains Portland clinker and at least one admixture with pozzolanic and/or hydraulic properties.
• Cement is a hydraulic binder which, when mixed with water, forms a slurry which solidifies and hardens due to a chemical hydraulic reaction and which is used in construction, especially as a binder for concrete.
• Cement is produced by firing limestone and clay together at temperatures around 1450 °C and by subsequent grinding of the produced clinker into a fine powder with a specific surface of 250 to 400 m 2 /kg.
• the current trend in cement production is the attempt to reduce its economic and environmental demands (the amount of C0 2 emissions from the production of Portland clinker ranges from 900 to 1000 kg/t, at specific heat consumption of 3500 to 4000 MJ/t). This is achieved by preparation of blended cements with partial replacement of Portland clinker with at least one suitable admixture with pozzolanic and/or hydraulic properties.
• blended Portland slag cement contains 6 to 20 % by weight, optionally up to 35 % by weight, of blast-furnace slag which exhibits hydraulic properties; blended Portland cement with microsilica contains 6 to 10 % by weight of microsilica which exhibits a large specific surface area and pozzolanic properties; blended Portland pozzolanic cement contains 6 to 20 % by weight, optionally up to 35 % by weight, of natural pozzolans or calcined natural pozzolans (substances of volcanic origin or activated by heat treatment); blended Portland fly ash cement contains 6 to 20 % by weight, optionally up to 35 % by weight of silica fly ash which exhibits pozzolanic properties, or calcium fly ash which exhibits both pozzolanic and hydraulic properties; blended Portland cement with calcined slate contains 6 to 20 % by weight, or up to 35 % by weight, of calcined slate which exhibits both hydraulic and pozzolanic properties; blended Portland cement with limestone contains 6 to 20 % by weight,
• blended cements may further contain up to 5 % by weight of calcium sulphate which modifies their solidification, e. g., in the form of gypsum (CaS0 4 .2H 2 0), calcium sulphate (CaSO 4 .0.5H 2 O) or anhydrite (CaS0 4 ), or mixtures of at least two of them.
• calcium sulphate which modifies their solidification, e. g., in the form of gypsum (CaS0 4 .2H 2 0), calcium sulphate (CaSO 4 .0.5H 2 O) or anhydrite (CaS0 4 ), or mixtures of at least two of them.
• the disadvantage of the known blended cements is that the currently used admixtures with pozzolanic and/or hydraulic properties have become a scarce commodity and due to this there has been a rapid growth in their price.
• the object of the invention is achieved by a blended cement containing Portland clinker and at least one admixture with pozzolanic and/or hydraulic properties, whose principle consists in that as an admixture with pozzolanic and/or hydraulic properties it contains inert construction and demolition waste and/or waste from industrial production of construction products in powder form with a particle size of 5 to 250 pm, preferably 5 to 125 pm, whereby the amount of all the admixtures ranges from 0.5 to 50 % by weight of the cement.
• the blended cement according to the invention may contain only inert construction and demolition waste and/or waste from industrial production of construction products in powder form, or it may contain this material in combination with at least one existing admixture for cement, such as blast furnace slag and/or at least one natural pozzolan and/or at least one calcined natural pozzolan and/or silica fly ash and/or calcium fly ash and/or calcined slate and/or limestone and/or microsilica, etc., whereby the amount of the inert construction and demolition waste and/or the waste from industrial production of construction products in the form of powder is at least 0.5 % by weight of the blended cement.
• at least one existing admixture for cement such as blast furnace slag and/or at least one natural pozzolan and/or at least one calcined natural pozzolan and/or silica fly ash and/or calcium fly ash and/or calcined slate and/or limestone and/or microsilica, etc.
• the blended cement according to the invention may further contain up to 5 % by weight of calcium sulphate in the form of gypsum, calcium sulphate, anhydrite or a mixture of at least two of them.
• the inert construction and demolition waste and/or the waste from industrial production of construction products in powder form may consist of finely ground inert construction and demolition waste and/or finely ground waste from the production of construction products, which consists entirely or of at least a majority of bricks and/or other brick products.
• this powder may consist of powder which is produced during the firing and grinding of fired bricks and/or other brick products.
• the inert construction and demolition waste and/or the waste from industrial production of construction products in powder form consists of finely ground inert construction and demolition waste, which consists entirely or of at least a majority of concrete.
• the inert construction and demolition waste and/or the waste from industrial production of construction products in powder form may consist of finely ground inert construction and demolition waste which consists entirely or of at least a majority of ceramic construction products and furnishing items.
• the inert construction and demolition waste and/or the waste from industrial production of construction products in powder form may consist of finely ground inert construction and demolition waste, which consists entirely or of at least a majority of mortar, plaster and similar materials.
• the inert construction and demolition waste and/or the waste from industrial production of construction products in powder form consists of finely ground inert construction and demolition waste which consists entirely or of at least a majority of a mixture of different building materials.
• the blended cement according to the invention contains Portland clinker and at least one admixture with pozzolanic and/or hydraulic properties, whereby as this admixture it contains inert construction and demolition waste and/or waste from industrial production of construction products in the form of finely ground powder with a particle size of 5 to 250 pm, preferably 5 to 125 pm.
• the fineness and specific surface area of this powder are similar to those of Portland clinker (specific surface area of this powder is approximately 300 to 1500 m 2 /kg, specific surface area of Portland clinker is usually approximately 250 to 400 m 2 /kg), and therefore it is possible to grind these components together, optionally to mix them immediately after grinding for further handling.
• the inert construction and demolition waste and/or the waste from industrial production of construction products in the form of finely ground powder consists of finely ground inert construction and demolition waste from demolition or construction of various types of constructions and/or waste from industrial production of various construction products.
• Suitable types of powder include, for example:
• inert construction and demolition waste inert construction and demolition waste
• waste from industrial production of construction products which consists entirely or of at least a majority of bricks and/or other brick products (with possible admixtures of other building materials and/or substances, such as concrete, ceramic building elements and furnishing items, residues of mortar, plaster, construction glue, etc.), scrap bricks and/or other brick products, etc., or it is powder which is produced during the firing and grinding of fired bricks and/or other brick products;
• inert construction and demolition waste inert construction and demolition waste
• construction products which consists entirely or of at least a majority of concrete (with possible admixtures of other building materials and/or substances, such as bricks, brick products, ceramic building elements and furnishing items, residues of mortar, plaster, construction glue, etc.), or scrap concrete products and prefabricated parts, etc., or powder produced by grinding concrete, etc.;
• inert construction and demolition waste which is produced by the fine grinding of mixed inert construction and demolition waste (incl. construction residues) and/or waste from industrial production of construction products, which is formed by a mixture of construction products and substances, usually bricks, brick products, concrete and ceramic building elements and furnishing items in different proportions (with a possible admixture of residues of mortar, plaster, gypsum, construction glue etc.), or is formed by mixing two or more above-mentioned powders (brick, ceramic, concrete, from mortar), etc.
• inert construction and demolition waste incl. construction residues
• construction products which is formed by a mixture of construction products and substances, usually bricks, brick products, concrete and ceramic building elements and furnishing items in different proportions (with a possible admixture of residues of mortar, plaster, gypsum, construction glue etc.), or is formed by mixing two or more above-mentioned powders (brick, ceramic, concrete, from mortar), etc.
• the advantage of concrete powder and powder from mortar is the fact that it contains a large amount of non-hydrated cement grains, which in combination with the absorbency of this powder make it possible to achieve a greater degree of hydration during concrete maturation and thus achieve higher concrete strength and/or reduce the required cement dose and thus the degree of autogenous shrinkage of this concrete.
• brick and ceramic powder contains a large amount of amorphous Si0 2 , which reacts with calcium hydroxide Ca(OH) 2 to form similar hydration products as cement does during the pozzolanic reaction - the so-called CSH phase.
• the mixed powder preferably combines concrete powder and/or powder from mortar with brick and/or ceramic powder.
• the amount of the inert construction and demolition waste and/or waste from industrial production of construction products in the form of finely ground powder in the blended cement according to the invention is in the range of 0.5 to 50 % by weight.
• the presence of inert construction and demolition waste and/or industrial waste in the form of powder has a positive influence on the properties and usability of the blended cement according to the invention as well as on the concrete prepared the concrete prepared using this cement.
• the powder provides the blended cement or the concrete prepared from it with self treating ability. At the same time, it does not affect the beginning of the hardening and solidification of the cement slurry and has a positive effect on the resulting strength of the cementing compound, especially after 90 or more days.
• the inert construction and demolition waste and/or the waste from industrial production of construction products in the form of finely ground powder can be supplemented with at least one known admixture for cement, such as blast-furnace slag and/or at least one natural pozzolan and/or at least one calcined natural pozzolan and/or silica fly ash and/or calcium fly ash and/or calcined slate and/or limestone and/or microsilica, whereby all the admixtures constitute 0.5 to 50 % by weight of the blended cement.
• the amount of the inert construction and demolition waste and/or the waste from industrial production of construction products in powder form is at least 0.5 % by weight of blended cement.
• the blended cement according to the invention may contain up to 5 % by weight of calcium sulphate in the form of gypsum, calcium sulphate, anhydrite or a mixture of at least two of them to modify the cement solidification process.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Civil Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)

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Citations (6)

• 2020
  • 2020-02-20 CZ CZ202085A patent/CZ202085A3/cs unknown
• 2021
  • 2021-02-19 WO PCT/CZ2021/050021 patent/WO2021164798A1/en not_active Ceased

Patent Citations (6)

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