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
  • 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
• • 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
  • C04B7/14—Cements containing slag
  • C04B7/147—Metallurgical slag
  • C04B7/153—Mixtures thereof with other inorganic cementitious materials or other activators
• • 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
  • C04B7/12—Natural pozzuolanas; Natural pozzuolana cements; Artificial pozzuolanas or artificial pozzuolana cements other than those obtained from waste or combustion residues, e.g. burned clay; Treating inorganic materials to improve their pozzuolanic characteristics
  • C04B7/13—Mixtures thereof with inorganic cementitious materials, e.g. Portland cements
• • 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
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00017—Aspects relating to the protection of the environment
• • 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
  • Y02W30/91—Use of waste materials as fillers for mortars or concrete

Definitions

• the invention refers to a concrete mix composition
• the invention refers to a hydraulic binder for producing such a concrete mix composition.
• Concrete is a very widely used construction material with high strength and good durability.
• Portland cement as a hydraulic binder, which produces strength-forming phases by solidifying and curing in contact with water. Concrete based on Portland cement clinker is thus one of the most important binders worldwide.
• the mineral additions typically between 10 and 50 wt.-% of the total binder weight, are in most applications ground granulated blast furnace slag, fly ash, pozzolans, ground limestone or mixtures thereof. It is known that in such composite binders, increasing the content of the
• the water-binder ratio of a concrete composition is the ratio of the weight of water to the weight of the hydraulic binder (including Portland cement and mineral additions) used in a concrete mix and has an important influence on the quality of the concrete produced.
• binders having an increased content of mineral additions a lower water- cement ratio is often used in order to increase strength and durability, but may make the mix more difficult to place. Placement difficulties can partly be resolved by using plasticizers or super-plasticizers, but such
• CA 2809225 Al describes a concrete composition
• the binder composition comprises 5-30 wt.-% of Portland cement, 0-20 wt.-% silica fume, 0-50 wt.-% fly ash and 42-75 wt.-% blast furnace slag.
• the invention described in CA 28909225 Al requires the use of ultra-fine reactive materials in order to reach sufficiently high strength values, which in turn may negatively affect fresh concrete properties and increases the total cost for the materials of the concrete.
• FR 2901268 Al describes a premixed binder composition and a concrete having a reduced CO 2 footprint. This is achieved by an optimization of the packing density of all components of the composition, from the ultra-fine binder particles to the aggregates.
• the use of high reactivity materials and the reduction of the water content in the concrete to very low water/cement ratios of 0,18 to 0,32 enables high strength developments.
• admixture dosage has on the concrete properties, especially the fresh concrete properties. Variations typically in the range of the accuracy of the scales used in ready mix plants would significantly increase the variability of fresh concrete properties, such as initial slump and slump retention. Due to these reasons the invention disclosed in FR 2901268 Al would prove to be difficult to implement in ready-mix operations and its total cost per cubic meter would be high.
• the invention is characterized in that the concrete mix composition
• the concrete mix composition essentially does not comprise any other constituents and therefore consists essentially of a hydraulic binder consisting of 35-45 wt.-% ordinary Portland cement and 55-65 wt.-% of a supplementary cementitious material, aggregates and a water reducing agent, wherein the water/binder ratio is 0,35-0,50.
• the hydraulic binder comprises ordinary Portland cement and supplementary cementitious materials in a weight ratio of 2:3.
• supplementary cementitious material compositions may also be used.
• a mixture of ground granulated blast furnace slag and fly ash may be used as said supplementary cementitious material.
• Other supplementary cementitious materials such as pozzolans and ground limestone may also be used.
• the supplementary cementitious materials such as pozzolans and ground limestone may also be used.
• the supplementary cementitious materials such as pozzolans and ground limestone may also be used.
• ground granulated blast furnace slag fly ash
• pozzolans ground limestone or mixtures thereof.
• the supplementary cementitious material content in the concrete mix design preferably lies between 160 and 230 kg per cubic meter of concrete. Preferably 180 kg of the supplementary cementitious material is used per cubic meter concrete .
• the inventive concrete mix composition also contains a water reducing agent, in order to improve the workability and to increase the initial setting time of the concrete.
• Water-reducing admixtures usually reduce the required water content for a concrete mixture by about 5 to 10 %.
• admixture needs less water to reach a required slump than untreated concrete.
• the admixtures used are typical commercially available water reducing agents, such as poly-carboxylate ether water reducers or polynaphthalene sulfonate based water reducers.
• the water reducing agent is present in an amount between 1,5 and 4,0 kg, preferably 2,1 kg, per cubic meter of concrete.
• the water reducing agent may be added in an amount suitable to reach a flow of the freshly mixed concrete at 10 min of 180 mm +/- 20 mm.
• admixtures as defined in EN-234 may also be used to improve specific properties of the concretes of the
• Retarding admixtures which slow the setting rate of concrete, are used to counteract the accelerating effect of hot weather on concrete setting. High
• the preferred Portland cement content in the concrete mix design is 110-130 kg, preferably 120 kg per cubic meter of Concrete .
• preferably is ⁇ 5 wt.-%, more preferably ⁇ 8 wt.-%.
• the concrete mix composition of the invention does not require highly reactive, ultra-fine cement or supplementary cementitious materials. Therefore, according to a. preferred embodiment of the invention the hydraulic binder has a Blaine fineness of 3000-5000 cm 2 /g.
• the ordinary Portland cement has a Blaine fineness of 3000-5000 cm 2 /g, preferably 4500 cm 2 /g
• the supplementary cementitious material has a Blaine fineness of 3500-6500 cm 2 /g, preferably 4500-5000 cm 2 /g.
• the specific types of Portland cements that achieve particularly good results within the instant invention preferably are such that have C3S (tricalcium silicate) content of the ordinary Portland cement of 55-65 wt.-%.
• the C3S content reflects the amount of 3CaO-Si0 2 in the Portland cement.
• the S0 3 (sulphate) content of the ordinary Portland cement is ⁇ 3,7 wt.-%.
• supplementary cementitious material particularly good results within the instant invention have been achieved with a supplementary cementitious material having a basicity (CaO/Si0 2 ratio) of ⁇ 1,0.
• a preferred embodiment of the invention provides that the aggregate is present in an amount of 1700-2100 kg, preferably 1850-2000 kg, per cubic meter of concrete.
• the aggregate may comprise the following particle size distribution:
• the inventive concrete mix design results in an excellent compressive strength and durability.
• the concrete has a 28d compressive strength of > 45 MPa, preferably > 50 MPa, in particular > 60 MPa.
• the concrete preferably has. a Id compressive strength of
• inventive concrete preferably has a 0 2 permeability of ⁇ 0,5 m 2 .10 ⁇ 16 . Further, the concrete preferably has a chloride penetration resistance of ⁇ 1000 Coulomb.
• the concrete has a carbonation speed of ⁇ 6 mm/Va. In a further preferred embodiment, the concrete has resistivity of ⁇ 1500 Q.m.
• a hydraulic binder is provided that is suitable for producing the inventive concrete mix composition, comprising 35-45 wt.-% ordinary Portland cement and 55-65 wt. ⁇ % of a supplementary cementitious material.
• Mortar was mixed with the mortar compositions as given in Table 1.
• a hydraulic binder was used, consisting of 40 wt . -% ordinary Portland cement and 60 wt.-% of ground granulated blast furnace slag (ggbfs).
• sand was used as the aggregate in an amount resulting from the sand/mortar ratio (S/M) as indicated.
• S/M sand/mortar ratio
• the sand/mortar ratio represents a volume ratio of the sand to the water, sand and binder.
• water was added to the mixture of hydraulic binder and aggregate in an amount resulting from the water/binder ratio (W/B) as indicated.
• the water/binder ratio represents a weight ratio of the water content to the binder (cement and ggbfs) .
• a water reducing agent was added to the mixture, the admixture dosage having been adjusted in order to reach a mortar flow at 10 min of 180 mm +/- 20 mm.
• the mortar flow was measured on a dry glass plate.
• the mortar was prepared and cured at 20 °C and their flow measured on a glass plate, strength was measured by casting 4x4x16 prisms, and setting times were measured according to ASTM. As can be seen from Table 2, the compositions of Table 1 have good early strength development, excellent 28 day strength value, and good setting times. In some cases, the strength is above 80 MPa at 91 days. Table 2
• a concrete was produced using the following
• composition :
• Plastol 341 is a polycarboxylate based plasticizing admixture.
• Example 2 The mix design of Example 2 was varied by using different types of Portland cement and of ggbfs and by choosing different admixtures.
• Table 3 shows three compositions using general use limestone cement.
• Table 4 shows two compositions using high early strength cement. Table 3
• the concrete mix designs of the invention have excellent strength development and excellent durability.
• the concrete of the invention has a C0 2 footprint of approx. 100 kg/m 3 .

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

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Publications (1)

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Cited By (3)

Citations (3)

• 2015
  • 2015-03-24 AT ATA171/2015A patent/AT517029B1/de not_active IP Right Cessation
• 2016
  • 2016-03-17 WO PCT/IB2016/000337 patent/WO2016151388A1/en active Application Filing

Patent Citations (3)

Non-Patent Citations (1)

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