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
  • C04B5/00—Treatment of  metallurgical  slag ; Artificial stone from molten  metallurgical  slag 
  • C04B5/06—Ingredients, other than water, added to the molten slag or to the granulating medium or before remelting; Treatment with gases or gas generating compounds, e.g. to obtain porous slag
• • 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
  • C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
  • C04B14/02—Granular materials, e.g. microballoons
  • C04B14/04—Silica-rich materials; Silicates
  • C04B14/22—Glass ; Devitrified glass
• • 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
  • C04B18/02—Agglomerated materials, e.g. artificial aggregates
  • C04B18/023—Fired or melted materials
• • 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
• • 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
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/00612—Uses not provided for elsewhere in C04B2111/00 as one or more layers of a layered structure
• • 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

• This invention relates to a cementitious mixture, articles produced from that mixture on setting and processes for producing such articles and the mixture itself.
• Concrete is generally formed from cement and an aggregate and additives for certain purposes mixed with water and allowed to set.
• the desired properties of the concrete product will vary dependent on the use of that particular product.
• High strength and long life are two of the most desirable properties.
• High strength can also be a factor of time with some products needing to achieve high strength over a short period of time while with others a slow increase in strength is acceptable.
• the life of a concrete product is again dependent upon particular use and the environment. Factors which can reduce the life of the concrete are the reactivity of the concrete to acid, the permeability to moisture and the alkali/silica reactivity.
• the susceptibility of any particular concrete to degradation conditions can be improved by using particular additives or varying the type of cement but this usually increase costs and also to the loss of other desirable properties of that concrete.
• a cementitious mixture suitable for mixing with water to form a cast or moulded article comprising cement and glass particles such that a substantial part thereof are of a fine particle size.
• the cement for use in the invention can be any suitable cement used in the trade for forming concrete of various types. Portland cement will generally be suitable It is a feature of the present invention that additives usually added to cement mixtures to accelerate setting or retard setting etc are not necessary but they can be included if there is ever a particular need to do so.
• a defoaming agent for removing air e.g. Bevaloid 5469DD - Rhone Poulenc
• a strength additive e.g. Rockite from Hartline Products Co Inc Cleveland, Ohio
• the important feature of the present invention is the particle size of the glass.
• a substantial proportion of the glass particles need to be of a fine size.
• the glass will have a particle size ranging from what is generally known as sand down to silt/clay. The largest particles will not normally be greater than 5mm except for specific type of products. Particle size will vary from 5mm right down to submicron sizes. It is believed that the key characteristics of concrete produced by glass particles lies in having a substantial proportion of a fine particle size.
• substantial is meant having sufficient particles present to influence the properties of the concrete in a favourable manner.
• fine particles is meant particles generally having a size less than 1 50 microns, e.g. less than 1 00 microns.
• the particle size distribution can be produced by crushing larger glass particles to give a range of particle sizes of from less than 5mm down to 1 micron or less.
• the manner of crushing can be varied to increase the ratio of fine particle sizes which may be required in certain situations as trial and error may show
• the glass aggregate can be produced by any suitable crushing means.
• One particular method is to use recycled glass and reduce it first in an Australian made Hammer Mill down to particle size less than 1 9mm. The crushed glass can then be further crushed in a Los Angeles Abrasion
• One particular glass aggregate of use in the invention is obtained by the above process after approximately one hour of crushing, and then screened over a 2mm BS sieve.
• a representative sample of the material passing the 2mm BS sieve was taken using the procedures set out in New Zealand standard 4402: 1 986. It was then tested to determine its particle size distribution.
• crushed glass produced by the above abrasion mill directly or to screen it through a sieve to reduce the proportion of large particles, e.g having glass particles no greater than 2mm or no greater than 600 microns or no greater than 1 50 microns. It is also within the scope of the invention to add to any glass aggregate, specific sized particles, e.g. very fine particles passing a 1 50 micron sieve to increase the proportion of such fine particles.
• larger aggregate particles are desired, then in accordance with the invention these can be chosen from glass aggregate of a size greater than 5mm. Where larger glass particles are added, then it is a preferred feature of the invention that these particles are scored by abrasion with finer glass particles entrapped in a Jetstream of air. This can happen in a suitable chamber which is rotated allowing the larger particles to tumble within the container and a compressed air blast is fed into the chamber from one end entrapping smaller particles within the Jetstream to impact on to the larger particles. Scoring the larger particles in this way adds to the keying effect of the other ingredients in the cementitious mixture.
• the glass particles of the invention can be chosen from a wide range of sources.
• Recycled glass e.g. from bottles or other waste glass products is a primary source of material for use in this invention in view of its cheapness.
• Currently preferred glass is recycled glass because of its significant purity.
• This invention also envisages using glass specifically made for use in the invention.
• the glass can be in various colours but the invention also envisages forming concrete having various colours through use of pigments. Glass used in high radiation situations, e.g. light bulbs, fluorescent tubes, heating elements, cathode ray tubes and microwave ovens, which is generally known as toughened glass and which has high tensile strength can be used for products where high insulation (thermal or electrical) is desired.
• Mixtures of glass from various sources can also be used.
• compositions of the invention can be made using normal cement where the alkali/silica reactivity is acceptable.
• the alkali/silica reactivity test is an accelerated test designed to model the long term effect of the alkaline reaction and generally an expansion under this accelerated test of less than 0.1 % change in length after 1 4 days is acceptable.
• a preferred composition having virtually no expansion under the alkali/silica reactivity test after 1 4 days was a composition consisting of cement and the glass composition of the invention in which the particles have substantially 1 00% less than 1 50 microns.
• the strength of concrete produced using this composition with Portland cement at a ratio 1 :3 in a water cement ratio 0.5 is not as great as that of other compositions of the invention Its 28 day strength was 1 5.5 MPa. This, however, is still acceptable for a number of commercial purposes.
• Increasing the strength of the glass composition itself can be achieved by adding other materials but, again, generally within a similar particle size range to that of the glass, i e. less than 5 mm.
• One suitable additive is slag produced as a by-product from steel making.
• the slag has given a major increase in strength to the glass of up to 51 MPa after 28 days.
• the product does have a higher than acceptable expansion under the alkali silica reactivity test but its abnormal strength, particularly, within one day after moulding makes it suitable for a number of building purposes where the alkali silica reactivity issue is not a problem.
• additives may be included to counter that effect in any concrete composition.
• the ratio of slag to glass can vary widely, from 1 0:90 (glass/slag) down to 90: 1 0 (glass/slag) .
• the glass will be the major component of the composition, more preferably slag will be present up to 40 percent.
• the glass/slag mixture can be formed by simply crushing the glass and the black slag separately to a particle size in the desired range and then intimately mixing the dry ingredients. Alternatively a mixture of large particles of glass and slag can be ground to the desired particle size range.
• an aggregate for mixing with cement comprising particulate glass and slag.
• a preferred process for creating an aggregate consisting of a glass/slag mixture is to mix crushed glass and crushed slag together fusing the mixture to intimately combine the glass and slag, allowing the mixture to set and then crushing into the desired particle size.
• a more preferred process for creating this aggregate is to mix crushed glass particles of less than 600 microns, more preferably 1 50 microns with crushed slag particles of less than 600 microns, more preferably 1 50 microns, liquifying the mixture under heat, mixing the liquified mixture, allowing to cool and then crushing. Desirably the cooled mixture is crushed to where the particles are between 1 mm and 5mm with the remainder of the mix then comprising the powdered glass of the invention with particles ranging from less than 1 mm down to less than 75 microns.
• the concrete formed with cement is found to be not only of a high strength but also has an acceptable result in the alkali silica reactivity test.
• Liquefaction of the mixture will usually occur at about 1 1 00 ° C but higher temperatures can be employed if required.
• the slag for use in this invention can be obtained as a by-product from steel making, which reduces the cost of the composition of the invention.
• the slag can also be produced directly from slag producing materials, for example iron sand.
• limestone as such or in the form of chalk or other natural source eg seashells such as pipi shells, which also appears to assist in the liquefaction of the slag/glass mixture.
• limestone is present in a small proportion, e.g. less than 1 0%, more preferably less than 5 % , such as about 1 % . Similar effects are achieved with dolomite or Zinc oxide.
• the slag powder of the invention is first desirably screened to remove magnetic materials. That is most conveniently done by crushing the slag and then passing the crushed powder over a magnet and collecting the nonmagnetic material.
• the concrete products of the invention are formed by mixing the cementitious product with water
• the dry ingredients can be first mixed together and then mixed with water.
• the ratio of cement to glass in total will generally be that chosen in normal concrete manufacture. This can vary from 1 % to 99 % (cement) to 99 % to 1 % (glass) . Varying the ratio will provide articles of different strength for use for different purposes.
• a suitable concrete product is formed using cement to dry ingredients ratio of from 1 : 2 to 1 :3.
• a feature of the invention is that the amount of water needed to form the strong concrete is substantially less than that required in normal concrete using river sand and river rock aggregate. This is believed to be because the glass particles do not absorb water and hence sufficient water is needed solely to rehydrate the cement to form the concrete bond.
• the amount of water can be selected to achieve the result required. Typically it will be in the range 0.4 up to 1 .3, preferably from 0.45 to 0.66.
• a moulded article in which cement mixed with glass particles having a substantial proportion of a fine particle size, optionally together with other aggregate particles, and water is allowed to set on a smooth surface, to form a concrete article with a consequential glossy surface.
• the provision of a glossy surface is believed to be unique in a cementitous product. This is believed to be achievable because the fine particles of glass bind together at the surface to form a substantially continuous film which when set imparts the gloss to it.
• the glossiness can be improved by setting the concrete under pressure optionally with a system for removing air.
• the cementitious mixture together with the appropriate amount of water is poured into a mould in which the bottom surface is a smooth surface of a material to which the concrete does not adhere, e.g. of a suitable plastic such as Perspex or Teflon.
• the base of the mould rests on a suitable supporting surface.
• the open mould will be filled with the mix to an extent to allow the open surface to be subject to pressure.
• a number of methods are envisaged to put the mixture under pressure while it is setting.
• One method currently envisaged is to have a slab which fits neatly within the mould contours to rest on the open surface of the cement mixture which slab can transmit a force uniformly to that cement mixture.
• a suitable weight can be put on the slab.
• That slab for example could be of steel or other strong metal able to resist distortion forces.
• that slab can be of thick timber construction, e.g. a thick particle board, suitably strengthened on its upper face to avoid distortions and to allow a force to be transmitted evenly to the upper surface of the cementitious material.
• a cradle can be formed, with a thick particle board as the base, of a size adapted to fit neatly within the mould, and having compartments constructed above its upper surface in a way to strengthen the particle board against distortion. These compartments are designed to carry heavy material.
• One of the most convenient heavy materials is iron sand because of its high weight to volume ratio.
• Moulded articles of the compositions of invention can be used to make building panels, e.g. for use in exterior surfaces of buildings.
• One advantage of the compositions of this invention for cladding panels is the low thermal conductivity leading to good insulation properties.
• the surface of the panel will generally be impervious to water and to acid conditions.
• the surface can be made glossy in the manner described above or have a matt finish if so desired.
• Pressure moulding can be also used to make decorative surfaced panels, e.g. for use in table tops such as coffee tables and such like. Many uses can be envisaged for such decorative surfaces.
• the degree of reflectiveness in the panels can be varied by varying the pressure applied during the settling procedure.
• the products of the invention can be coloured. Different colours can be achieved by adding a pigment to the cementitious mixture.
• the glass particles themselves are impervious to water and hence the water soluble pigment will be taken up solely in the cement, interstitial water or other aggregate when added. It is a further feature of the invention to be able to create multicoloured layers.
• the cementitious composition of the invention is poured into a mould, the free surface is found to be significantly resistant to transfer of liquid. A "skin" appears to form on the surface. If another layer of cementitious product of a different colour is poured over a first layer while it is still wet, it is found that the migration of one colour into the other is not substantial.
• the invention therefore provides a multi-layered concrete product formed by pouring a first layer of a cementitious product containing glass particles a substantial proportion of which are of a fine particle size and a first colour into a mould, and then pouring over the first layer, before the first layer has substantially set, a second layer of a cementitious product containing cement and glass particles, a substantial proportion of which are of a fine particle size, and a second colour, and if desired pouring a third or more layers of a different colour.
• Another feature of the formed concrete product of the invention is in general the ease with which it can be cut Cutting with a normal concrete saw involves so much less effort than cutting a normal concrete panel This is despite the significant strength which the concrete products of the invention have. Exactly why the panels can be cut so much more easily is not known
• a further feature of the invention is that the surface along the cut will itself be smooth and even glossy depending upon the fineness of the saw blade used in the cutting process.
• the concrete also has low thermal conductivity.
• Products in accordance with the invention can be used for many purposes. For example, gravestones, insulators, roof tiles, floor tiles, external cladding, slate, concrete decking, e.g. swimming pools, surfaces and surrounds, ceramic style products, marble like products, pipes, precast panels, sink tops, bar tops, bathroom tops, table tops, file cabinets, fireplace tiles, fire proof walls, building blocks etc.
• the expansion test is ASTMC 1 260. This requires less than 0. 1 % expansion after 1 4 days.
• Example 1
• a mixture of 60 parts glass particles and 40 parts black slag particles (obtained from an induction furnace) both of less than 1 50 microns together with 1 % of limestone powder were heated in a furnace to about
• Example 4 1 1 00 ° C to melt the powders. The melt was stirred to intimately mix the components together and the whole mass was allowed to cool to room temperature. The solid rock like material can then be crushed to the desired particle size.
• Example 4 1 1 00 ° C to melt the powders. The melt was stirred to intimately mix the components together and the whole mass was allowed to cool to room temperature. The solid rock like material can then be crushed to the desired particle size.
• Example 5 Particles of the glass/slag mix of Example 3 were mixed with cement and water in a ratio glass/slag:cement of 2.25: 1 and a wate ⁇ cement ratio of 0.66 and allowed to set. The strength after 7 days was 26.5 MPa and the expansion after 1 4 days was 0.002 % .
• Example 5
• a glass/slag mix is prepared as in Example 3.
• the solid rock like product is crushed to the following particle size range.
• Example 6 A glass/slag mix was prepared as in Example 3 except using 85 parts glass and
• the compressive strength was as follows:
• the concrete was formed with Portland cement in a ratio glass/slag: cement of 2.25 : 1 and wate ⁇ cement ratio of 0.66.
• the strength after 1 day was 30 MPa, after 2 days 50 MPa and after 3 days 55MPa.
• the expansion was - 0.002 after 1 4 days (i.e. a slight shrinkage) .
• the invention can be industrially applied in a number of ways.
• the aggregate consisting of the glass particles, glass/slag particles prior to or after fusion are potential commercial products as are the concrete products formed from the use of the aggregate together with cement for many purposes as setforth herein.

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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)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Processing Of Solid Wastes (AREA)

Applications Claiming Priority (5)

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• 1997
  • 1997-10-16 AU AU47289/97A patent/AU4728997A/en not_active Abandoned
  • 1997-10-16 BR BR9712526A patent/BR9712526A/pt not_active Application Discontinuation
  • 1997-10-16 CN CN97198752A patent/CN1233233A/zh active Pending
  • 1997-10-16 PL PL33277297A patent/PL332772A1/xx unknown
  • 1997-10-16 IL IL12944697A patent/IL129446A0/xx unknown
  • 1997-10-16 JP JP51822898A patent/JP2001504792A/ja active Pending
  • 1997-10-16 WO PCT/NZ1997/000138 patent/WO1998016483A1/en not_active Application Discontinuation
  • 1997-10-16 CA CA 2268625 patent/CA2268625A1/en not_active Abandoned
  • 1997-10-16 EP EP97909762A patent/EP1032544A4/de not_active Withdrawn
• 1999
  • 1999-04-13 NO NO991749A patent/NO991749L/no not_active Application Discontinuation

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