WO2015198178A1

WO2015198178A1 - A coated concrete casting and method for producing same

Info

Publication number: WO2015198178A1
Application number: PCT/IB2015/054314
Authority: WO
Inventors: Israel PAYCZER
Original assignee: Payczer Israel
Priority date: 2014-06-25
Filing date: 2015-06-08
Publication date: 2015-12-30
Also published as: WO2015198178A4

Abstract

A monolithic concrete casting has an outer coating integrally formed with the casting. The coating has an additive of a resin and/or a polymeric and/or acrylic and/or a chemical and/or a mineral; type. The additive is added to a mixture forming the concrete casting.

Description

A COATED CONCRETE CASTING AND METHOD FOR PRODUCING

SAME

TECHNICAL FIELD

[001] Embodiments of the invention relate to a coated concrete casting and a method for forming the coated concrete casting, and in particular to a monolithic type casting.

BACKGROUND

[002] Concrete is a composite material typically composed of ingredients such as water, coarse granular material and cement consisting of a mixture of oxides such as calcium, silicon and aluminum. Production of concrete typically consists of a process including mixing together the ingredients, possibly with additives.

[003] Concrete production may take place e.g. in a central facility or on the construction site where it is intended to be used. The mixed concrete for example when produced in a central facility, may be kept in hoppers and from there dispensed into concrete mixer trucks for being hauled to the location where its is intended to be casted into formwork.

[004] Coatings can be used to protect concrete castings from damage and extend its useful life by e.g. sealing the casting against penetration of substances such as chemicals. A typical coated concrete casting may be obtained by first producing a pre-prepared concrete casting that is left to cure and solidify in order to serve as a substrate. After curing, several layers of coatings may then be applied over the substrate. [005] Such coated concrete casting however may have some disadvantages. The coating applied to the casting may peel off in time due to e.g. mechanical stress heat, UV radiation, chemical corrosion, inherent weakness of molecules forming the coating, or simply due to errors in the application of the coating on the substrate casting.

[006] In addition, its production is time consuming since the curing of the concrete substrate may take several days or even weeks until the coating may be applied. In addition, grinding and priming processes typically performed prior to the application of the coatings may well take some additional weeks, in particular when using epoxy based coatings, until the coated concrete casting may be ready for service.

[007] Various technologies and methods have been developed and employed for improving cemented concrete casting technologies, some of which suggest overlay layers for being placed on substrates.

[008] US5695811 for example describes a method for bonding a hydrating cement-based overlay onto a cement-based substrate. An integral bond is created between the overlay and the substrate by maximizing capillary suction through properly preparing the substrate and designing the overlay. The integral bond has an interface strength at least substantially similar to the substrate strength. The substrate is prepared to optimize the capillary suction by cleaning and optimal water saturation.

[009] EP2189427 describes use of foamed polystyrene and cement for mortar buildings. The mortar contains the foamed polystyrene and e.g. a part of the cement in the form of a ground material including granules. For the production of the mortar, pressed foam concrete that has been allowed to stand and which contains polystyrene foam is ground into granules and to that cement is added together with water.

[010] US2012053266 relates to a polymeric-additive for cement such as Portland Cement that improves its compression and tensile strength. The additive is stable at sub-freezing temperatures prior to use and relatively low in cost and easily mixed with the cement prior to utilization. The additive may be controlled such that the cement may be applied by both gunning and casting techniques. SUMMARY

[Oi l] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope.

[012] In accordance with a broad aspect of the invention there is provided a monolithic concrete casting comprising an outer coating integrally formed with the casting. The outer coating may be formed within the casting and preferably not as a separate layer or coat coated and/or added to a casting during or after curing stages of the casting.

[013] In a broad form of an aspect of the invention, the coating comprises an additive. The additive may be mostly in the coating and/or dispersed in the casting to also be present in the coating.

[014] In an embodiment, the additive is a resin-additive and/or a polymeric- additive and/or an acrylic-additive and/or a chemical-additive and/or a mineral- additive. The additive may comprise in an embodiment a specific gravity less than about 1.0 and/or a suitable viscosity possibly a low viscosity close to about water viscosity or less, in order to assist in migration of the additive, preferably upward migration, in the casing during its formation and preferably before curing or substantial curing of the casting. In various embodiments, the additive may combine with at least free calcium, and/or bleeding (e.g. excessive) iron oxide and/or bleeding (i.e. excessive) liquids (e.g. water) coming out of (or dispersed in) the concrete to chemically join them into a monolith coat in the concrete casting.

[015] The migration may form the coating and/or assist to form a coating providing various embodiments of the casting of the invention with at last one of: improved leak-proof (Gas/Water), improved abrasion resistance, improved chemical resistance (to e.g. gasoline, mineral oil, solvents, acids), improved fork lift-truck resistant, improved tire-mark proof, improved dust proof, improved total UV resistance, improved Crack resistance, improved compressive strength, alleviation from plastic cracking, increased density, increased impermeability and durability, lower internal chemical reaction potential.

[016] In various embodiments, the additive may preferably be of a chemical and/or a Fatty/Oleic Acid type, and/or a DM additive/admixture, preferably a DM concrete additive/admixture. Such preference in some embodiments may be due to low weight ratio of such additive relative to cement weight in the casting resulting e.g. in lower production costs. Other possibly advantages may be faster curing time.

[017] In a broad aspect of the invention there is also provided a method of producing a monolithic concrete casting comprising the steps of: providing a concrete mixture comprising mixing an additive, cement and liquid, preferably water, adding the concrete mixture to a formwork, applying smoothing to the concrete mixture in the formwork, wherein at least after curing, the concrete mixture in the formwork forms a concrete casting comprising a coating at an outer side of the concrete casting and integral with the concrete casting.

[018] In various embodiments, the method also comprises a step of applying vibration to the concrete mixture in the formwork, preferably prior to the applying of smoothing. Such vibration may assist in movement of substances in the casting preferably substances forming the coating.

[019] In a broad form of one aspect of the invention the smoothing forms a venturi effect at the outer side of the concrete casting urging at least some substances in the concrete mixture to be sucked to move towards the outer side. Preferably the substances are the additive and additional substances possibly those forming a skin in normal concrete casting.

[020] In various embodiments, the moving of additive and substances may possibly be while same being combined preferably chemically combined, and possibly the movement may be via capillary channels in the casting resulting in blocking of at least some of said channels.

[021] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.

BRIEF DESCRIPTION OF THE FIGURES

[022] Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying figures, in which:

[023] Fig. 1 schematically shows an additive in accordance with an embodiment of the invention added to a concrete mixture in a mixer truck;

[024] Fig. 2 schematically shows a concrete mixture containing an embodiment of an additive of the invention being deposited onto a formwork, as part of a possible step in the forming of an embodiment of a concrete casting;

[025] Fig. 3 schematically shows a possible step in the forming of an embodiment of a concrete casting, including vibrating the casting seen in Fig. 2 using a concrete vibrator;

[026] Fig. 4 schematically shows a cross sectional view of a portion of the casting of Fig. 3; and

[027] Fig. 5 schematically shows a possible step in the forming of an embodiment of a concrete casting, including smoothing the upper surface of the portion of the casting seen in Fig. 4 with a mechanical trowel.

[028] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.

DETAILED DESCRIPTION

[029] Attention is first drawn to Fig. 1 showing an action of pouring an additive 10 in accordance with an embodiment of the invention from a source 8, such as a container, into a concrete mixture located within a mixer truck 12, in accordance with one possible form of producing a concrete casting of the present invention. It is noted that embodiments of the production method of the present invention may not be limited to steps including use of a mixer struck, and mixing of e.g. liquid (e.g. water), coarse granular material and cement may be performed on- site (e.g. construction site) or in any other commonly known method and/or means.

[030] In accordance with various embodiments of the present invention, the additive may be added to the concrete mixture at various stages including stages other than the one seen in this figure. For example, the adding of the additive may be to a mixture liquid (e.g. water) e.g. prior to it's adding to the concrete mixture; and/or to substances/additives added to the concrete mixture such as abrasion resistance substances; and/or coloring pigments (e.g. Iron Oxide pigment Fe₂O₃); (etc.).

[031] The additive may be a resin-additive and/or a polymeric-additive and/or an acrylic-additive and/or a chemical-additive and/or a mineral- additive; and preferably with a specific gravity lower than 1.0 (where reference substance is water). The additive in various embodiments may also be a 99% active agent.

[032] In several examples, the additive may be: a resin such as a Hydroxyl- terminated polybutadiene (HTPB), and/or a chemical and/or a Fatty/Oleic Acid, and/or a Water-Borne Acrylic Epoxy, and/or a DM concrete additive/admixture, and/or any other DM additive/admixture, (etc.).

[033] Examples of additives may be: the Poly-bd trademark of Cray Valley Hydrocarbon Specialty Chemicals (HSC), the TEOS or HYDRO PLAST or HydroPhob B-WE (DM) or HydroPlast AW trademarks of BETRA Beton- und Baustoffverfahrenstechnik GmbH, the PITT-GLAZE trademark of PPG Industries Inc., PURCOLOR 6000 of SCHOMBURG ICS GmbH, (etc.). Various embodiments of such additives may be defined as: mass-hydrophobic-agent and plasticizer, as having isomeric octyltriethoxysilanes with n-octyltriethoxysilane as main component, as mass-hydrophobic admixture on the basis of highly-reactive silanes and synergetic additives.

[034] The additive of preferred embodiments of the invention may be (or include) one or more of the following: of a type not requiring assistance (i.e. not requiring a catalyst such as nitrogen or high temperature) in its curing (such as e.g. a Fatty/Oleic Acid type additive); have a low viscosity close to about water viscosity or less and preferably lower than about 0.99 [mPa- s] at 25°c, more preferably lower that about 0.91 [mPa- s] at 25 °c; of a type combinable with substances normally forming a skin in normal castings such as free-calcium and oxide iron and liquid preferably water and more preferably bleeding water (i.e. excessive water in the concrete).

[035] In preferred embodiments of the invention, the weight of the additive may be determined as being between about 0.2-30% of a weight of the cement in (or to be added to) a concrete mixture. Preferably the additive weight may be between about 0.2-20%, more preferably between about 0.2-10%, and even more preferably between about 0.2-2%; of a weight of the cement in (or to be added to) a concrete mixture.

[036] Lower additive weight may contribute to reduce costs of a production of various embodiments of a concrete casting and possibly faster curing times. Possibly, upper ends of the weight percent ranges may be associated to an embodiment of an additive of e.g. a mineral type, and the lower ends of the weight percent ranges may be associated to an embodiment of an additive of e.g. a chemical and/or a Fatty/Oleic Acid type. [037] By way of a non-binding example, a weight of a HTPB type additive may be about 5% of a weight of a cement in (or to be added to) a concrete mixture, a weight of a Water-Borne Acrylic Epoxy type additive may be between about 0.2- 10% of a weight of a cement in (or to be added to) a concrete mixture, a weight of a DM concrete type additive/admixture may be between about 0.2-3% of a weight of a cement in (or to be added to) a concrete mixture.

[038] By way of an example, in a 1 cubic meter concrete casting requiring 350 kg of cement for its production, the additive weight may be between about 0.7 kg to about 105 kg for the 0.2-30% weight range, with additive weights closer to the lower end of 0.7 kg being for e.g. chemical and/or Fatty/Oleic Acid type additives and weights closer to the upper end of 105 kg being for e.g. mineral type additives.

[039] In an embodiment, the additive may be added to the concrete mixture at the factory or at the construction site, possibly mixed together with the concrete mixture for at least about 3 minutes, preferably at least about 5 minutes, more preferably at least about 15 minutes.

[040] Attention is drawn to Fig. 2 showing a concrete mixture 14 including an additive of an embodiment of the invention being poured to a formwork 16 directly or by pump (or the like) to form a concrete casting 18.

[041] The term formwork should be understood in a broad aspect to relate to any e.g. means suitable to receive (or interact with or support) a concrete mixture for forming a concrete casting, such as (but not limited to): a mold and/or structure and/or slab and/or structural system and/or coffor and/or re-usable system and/or timber or plastic system and/or metal/steel grid and/or foundation, (etc.)

[042] With attention drawn to Fig. 3 a possible production step in the formation of the concrete casing 18 according to an embodiment is seen, which includes vibrating (possible compacting) the casting 18 using a concrete vibrator 20 to form a given region 22 in the concrete casting where vibration has been performed.

[043] Attention is now drawn to Fig. 3. In the concrete mixture casted to formwork 16 to form concrete casting 18; substances such as calcium (Calcium hydroxide Ca(OH)₂), liquid (e.g. water), the polymeric-additive, (etc.) may rise (float) upwards via e.g. capillary channels in the casting. The wavy arrows in this figure represent such rising. Such rising substances may preferably be promoted in the region 22 due to the vibration of the vibrator 20.

[044] In an embodiment, the additive preferably has a specific gravity smaller than about 1.0 to assist its surfacing/rising/floating to the upper layer of the concrete casting. The upwardly moving additive, while being transported via e.g. the capillary channels in the casting, chemically bonds/combines with the liquid (e.g. bleeding excessive water) and e.g. free calcium in the casting. Also seen in this figure is a basing 24 upon which casting 18 may be formed. Basing 24 may be an infrastructure on which formwork 16 was located/placed such as an earth or soil, a thin layer of concrete (or the like).

[045] Attention is drawn to Fig. 5 showing a possible production step in the formation of the concrete casing 18 according to an embodiment of the invention, which includes smoothing the upper surface of the casting 18 with a mechanical trowel 26. In one form of the invention, mechanical trowel 26 in addition (or while) smoothing casting 18 further forms a venturi effect assisting in sucking and floating the additive and substances such as liquid (e.g. excessive bleeding water), calcium (and possibly color pigment); upwards in the casting towards the upper layer of the casting, while possibly plugging during the upwards movement (at least part or substantially most) of the capillary channels in the casting. The straight arrows in this figure represent venturi assisted rising.

[046] In an embodiment, the result of such rise of additive and substances (preferably chemically bonded to the additive) forms a, preferably chemically and physically combined, outer coating 28 of casting 18 that may preferably be a hydrophobic coating. Coating 28 forms an integral part of the casting, and in other words monolithic casting 18 includes at its top side a coating 28 acting to protect the casting 18 which may not be susceptive to peeling off. Coating 28 may preferably last as long as the casting thus having an increased durability and fast application. [047] Coated casting 18 thus may in various embodiments have at least one of: improved leak-proof (Gas/Water), improved abrasion resistance, improved chemical resistance (to e.g. gasoline, mineral oil, solvents, acids), improved fork lift-truck resistant, improved tire-mark proof, improved dust proof, improved total UV resistance, improved Crack resistance, improved compressive strength, alleviation from plastic cracking, increased density, increased impermeability and durability, lower internal chemical reaction potential, (etc.).

[048] Various embodiments of casting 18 of the invention may also be defined as in compliance with at least one of the following standards or definitions: EN 934- 2-2012 and EN 934-2.T.9, EN 206-1, ASTM C-67 Section 7, 9 and 10, ASTM C- 666, ASTM C-23-69..

[049] In an embodiment, curing of casting 18 after the above discussed possible production steps may take no more than about 3 days and preferably no more than about 1 day.

[050] Possible uses of embodiments of the concrete casting of the present invention may be (but not limited to): industrial facilities, factory floors, airplane hangers, retail facilities, car parks, run-ways, ware-houses, (etc.).

[051] It should be noted that directional terms appearing throughout the specification and claims, e.g. "forward", "rear", "up", "down" etc., (and derivatives thereof) are for illustrative purposes only, and are not intended to limit the scope of the appended claims. In addition it is noted that the directional terms "down", "below" and "lower" (and derivatives thereof) define identical directions.

[052] In the description and claims of the present application, each of the verbs, "comprise" "include" and "have", and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.

[053] Further more, while the present application or technology has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and non- restrictive; the technology is thus not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed technology, from a study of the drawings, the technology, and the appended claims.

[054] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures can not be used to advantage.

[055] The present technology is also understood to encompass the exact terms, features, numerical values or ranges etc., if in here such terms, features, numerical values or ranges etc. are referred to in connection with terms such as "about, ca., substantially, generally, at least" etc. In other words, "about 3" shall also comprise "3" or "substantially perpendicular" shall also comprise "perpendicular". Any reference signs in the claims should not be considered as limiting the scope.

[056] Although the present embodiments have been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the invention as hereinafter claimed.

Claims

CLAIMS:

1. A monolithic concrete casting comprising an outer coating integrally formed with the casting.

2. The concrete casting of claim 1, wherein at least the coating comprising an additive.

3. The concrete casting of claim 2, wherein the additive is a resin-additive and/or a polymeric-additive and/or an acrylic-additive and/or a chemical-additive and/or a mineral- additive .

4. The concrete casting of claims 2 or 3, wherein the additive comprising a specific gravity less than about 1.0.

5. The concrete casting of any one of claims 2 to 4, wherein the additive is of a chemical and/or a Fatty/Oleic Acid type.

6. The concrete casting of any one of claims 2 to 5, wherein the additive is a DM additive/admixture, preferably a DM concrete additive/admixture.

7. The concrete casting of any one of claims 2 to 6, wherein the additive comprising a low viscosity close to about water viscosity or less.

8. The concrete casting of any one of claims 2 to 7, wherein the additive comprising a viscosity that is lower than about 0.99 [mPa- s] at 25 °c, preferably lower that about 0.91 [mPa- s] at 25°c.

9. The concrete casting of any one of claims 2 to 8, wherein the additive is adapted to be combinable with at least one of the substances: free-calcium, oxide iron, and liquid; in the concrete casting.

10. The concrete casting of claim 9, wherein the liquid is water, preferably bleeding excessive water in the concrete casting, and/or the oxide iron is preferably bleeding excessive oxide iron in the concrete casting, and/or the additive is adapted to be chemically combinable with the at least one of the substances.

11. The concrete casting of any one of claims 2 to 10, wherein a weight of the additive is between about 0.2-30% of a weight of a cement in the concrete casting.

12. The concrete casting of any one of the preceding claims, wherein the coating is a hydrophobic coating.

13. A method of producing a monolithic concrete casting comprising the steps of: providing a concrete mixture comprising mixing an additive, cement and liquid, preferably water,

adding the concrete mixture to a formwork,

applying smoothing to the concrete mixture in the formwork, wherein at least after curing, the concrete mixture in the formwork forms a concrete casting comprising a coating at an outer side of the concrete casting, wherein the coating is integrally formed with the concrete casting.

14. The method of claim 13 and comprising a step of applying vibration to the concrete mixture in the formwork, preferably prior to the applying of smoothing.

15. The method of claim 13 or 14, wherein the applying is to the outer side of the concrete casting where the coating is formed.

16. The method of any one of claims 13 to 15, wherein the outer side is an upper side of the concrete casting.

17. The method of any one of claims 13 to 16, wherein the smoothing forms a venturi effect at the outer side of the concrete casting urging at least some substances in the concrete mixture to be sucked to move towards the outer side.

18. The method of claim 17, wherein the at least some substances comprise at least some of the the additive.

19. The method of any one of claims 13 to 18, wherein the additive comprising a specific gravity less than about 1.0.

20. The method of any one of claims 13 to 19, wherein the additive is a resin- additive and/or a polymeric-additive and/or an acrylic-additive and/or a chemical- additive and/or a mineral- additive.

21. The method of any one of claims 13 to 20, wherein the additive is of a chemical and/or a Fatty/Oleic Acid type.

22. The method of any one of claims 13 to 21, wherein the additive is a DM additive/admixture, preferably a DM concrete additive/admixture.

23. The method of any one of claims 13 to 22, wherein the additive comprising a low viscosity close to about water viscosity or less.

24. The method of any one of claims 13 to 23, wherein the additive comprising a viscosity lower than about 0.99 [mPa- s] at 25°c, preferably lower than about 0.91 [mPa- s] at 25°c.

25. The method of any one of claims 17 to 24 when dependant on claim 17, wherein the at least some substances comprise at least one of: the additive, free- calcium, oxide iron, and liquid, preferably bleeding oxide iron and liquid.

26. The method of claim 25, wherein moving comprises moving at least some of the additive towards the outer side of the concrete casting, wherein said moving of additive comprises bonding, preferably chemically bonding, of the additive with at least one of free-calcium, oxide iron, and liquid.

27. The method of any one of claims 17 to 26 when dependant on claim 17, wherein at least part of the moving is via capillary channels in the concrete casting.

28. The method of any one of claims 13 to 27, wherein the coating is a hydrophobic coating.