Composition and method for obtaining exposed aggregates in surfaces of moulded concrete and other cementitious materials.

(54) Title: COMPOSITION AND METHOD FOR OBTAINING EXPOSED AGGREGATES IN MOLDED CONCRETE SURFACES AND OTHER CEMENT MATERIALS.

(54) Title: COMPOSITION AND METHOD FOR OBTAINING EXPOSED AGGREGATES IN SURFACES OF MOULDED CONCRETE AND OTHER CEMENTITIOUS MATERIALS.

(57) Summary

The surface retarding coating compositions of the invention are based on the use of at least one Non-Common Portland Cement (non-OPC) binder and at least one retarding set OPC agent, which are provided in powder form. can be mixed with water on the construction site. The coating is applied to the surface of a mold or formwork using roller or spray equipment, and the concrete can then be cast within 30-60 minutes against the coating. The OPC setting retarding agent operates to retard the setting of the concrete so that it can be removed from the mold the next day and its surface can be removed with high pressure water spray to reveal the embedded aggregate below the removed surface.

(57) Abstract

Surface retarder coatíng compositions of the invention are based on the use of at least one non-Ordinary Portland Cement (non-OPC) binder and at least one OPC set retarder agent, which are provided in powder form that can be mixed with water at the construction site. The coating is applied onto the surface of a mold or formwork using roller or spray equipment, and concrete can then be cast within 30-60 minutes against the coating. The OPC set-retarding agent operates to retard setting of the concrete so that it can be demoulded the next day and its surface can be removed using a high pressure water spray to reveal aggregate embedded beneath the removed surface.

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PATENT TITLE No. 354536

Headlines):

Home:

GCP APPLIED TECHNOLOGIES INC.

Whittemore Avenue, Cambridge, Massachusetts, 02140, USA

D nomination:

Classification:

COMPOSITION AND METHOD FOR OBTAINING EXPOSED AGGREGATES ON MOLDED CONCRETE SURFACES AND OTHER CEMENT MATERIALS. ._? to ·

C04 | B28 / & ^ 0W & M G04¡3> 8 / 1WB28 / 18

B28B7 / 36; B28B7 / 362; B28B7 / 384 * '/ /.

DANYMfíCENT; ERIC

CIP: CPC:

MX / a / 20

Validity: VB

Date

Date of

Inventors):

Jntemaefonal:

Reference patent

In accordance with the article as of the date of submission

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re 2032 ustnaT, the article

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Who subscribes to this title lolW (Official Gazette of the Federation (Q 25/01/2006, 06/05 / 2009,06 / 01/2010, ΐ ____—

Regulations of the Mexican Institute of the EJr ^ ied articles 1, 3, 4, 5, section V, subsection a), 16 f · 12/27/1999, amended on 10/10/2002, 07/29/2004, Deputy Generals, Coordinator, Divisio Departmental Directors and other subordinates of the Mexican Institute of 08/04/2004 and 09/13/2007).

jie'twLaw of Industrial Property.

ñWjn · wgelfcia of twenty years' extendable, counted to ifa p ^ Mnantener current rights jpnes lll jÓ * ¿fs&gt; cle Ja Law of Industrial Property I 26j | 2 / ^ 87 »^ 1» 08/1999, 26/01 / 2004, 06/16/2005, taA®y # c¡so a), 4^or and 12th sections I and III of ®2Ο (0ΓΪ5 / Ο7 / 2ΟΟ4, 07/28/2004 and 09/07/2007); lowlexicano of Industrial Property (a sound DOF that delegates powers to the National Directors, Divisional Sub-Directors, Trial Coordinators. (DOF 12/15/1999, amended on 02/04/2000, 07/29/2004,

This letter is signed with an advanced electronic signature (FIEL), based on articles 7 BIS 2 of the Industrial Property Law; 3rd of its Regulations, and 1 section III, 2 section V, 26 BIS and 26 TÉR of the Agreement establishing the guidelines for the use of the Electronic Payment and Services Portal (PASE) of the Mexican Institute of Industrial Property, in the procedures indicated.

THE DIVISIONAL DIRECTOR OF PATENTS

NAHANNY CANAL REYES

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NAHANNY MARISOL CANAL REYES | 00001000000403252793 | Administration Service

Tax | 1695 || MX / 2018/20142 | MX / a / 2014/006389 | PCT patent title | 1223 | GAGV | Page (s) | jfYWXoKmuLiT32kktX / 2qSp8zBQ =

Digital stamp:

aVin91j3WwNYqSQ45XGXJqRO / CsveAnauZU + tP1xJ / y9k1zf7TJ7opw4iujgV5E9VnXmZSUaqKJOIoDeGHa / x7ZebE 5oJo5lyV1X / NsrWzDnG / ESQtVpWgRkyXxWcofKr3Jp4M7kFA3L8kb8HE / BmlPd / W69BY3mMqt2cuplS3ScNlcchSLo JP3umDIJbVzac33oXnTOemRvc8bOxQNm8jwsDfF 9Gufnz5rkQJKCaQjgcKf3yk53e3s1Tultf + + + H4kauYEL WXNsLv18nsC2s1 HulY4xiEcludyzxPisWNhEjMLxReCDFXAu5RbU3EO1aTLQ42cjsozdghJO // == 2LA

Arenal No. 550. Floor 1, Pueblo Santa María Tepepan. Xochiinilco 16020. Mexico City.

(55) 53340700 www.gob.rnx / impi

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MX / 2018/20142 f »

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COMPOSITION AND METHOD FOR OBTAINING EXPOSED ADDERS ON MOLDED CONCRETE SURFACES AND OTHER CEMENT MATERIALS

Field of; the invention

The present invention relates to the manufacture of articles produced from hi dra tabi.es cement compositions, such as pane l is pre-concrete concrete, walls, and other articles, and more particularly to a new retarding composition of the concrete surface that contains setting agents for surgical cement setting to obtain exposed aggregate surfaces after removing the cement or the concrete article from form 1 of formwork.

BACKGROUND OF THE INVENTION

The application of concrete surface retarders to the internal surfaces of molds or formwork (which are essentially large-scale molds of assembled planks of wood or formwork for the manufacture of walls, foundations, etc.) is known. ), and exposure of aggregates on the surface of the cast concrete form or article. It is usual for commercial concrete surface retarding products in form to be provided in the form of solvent-based compositions.

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These products are typically sprayed or TmTT1 1 * · η- ^ nbre the interior surfaces of the concrete or formwork moJ.

The. portion of the cement paste from the concrete, which has been in contact with the surface retardant coating, can be removed by. use of pressurized water (aerosol) to expose aggregates that are embedded in concrete below its removed surface. Most commonly used release surface retarders incorporate solvents for their fast drying characteristics. However, solvents raise environmental, health, and safety issues, and are therefore subject to strict regulation in many countries. Manufacturers have tried to replace solvents with water-based products for these reasons. However, water-based formulations have longer drying times compared to solvent-based formulations.

Many precast operations take place in open, unheated areas, and these are not favorable conditions for achieving rapid test times when using conventional water-based products, because the rate of water evaporation is greatly hampered. This condition is particularly noticeable in winter weather, when temperatures are low and the relative humidity is high due to the humid environment of the «

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concrete. Manufacturers of pre''I.IUujj do ^ cn.yrrrto panels, for example, should plan to apply water-based surface retardant products very early in the day. Concrete panels often need to be heated inside. Formwork to reduce drying time so that at least one concrete panel can be produced from the formwork for each day of operation.

In World Patent Application No. WO

2002/003448 from Grace Construction Producís, describes a method to increase productivity levels without relying on harmful solvents. In this method, a hot melt coating composition containing surface retarding active substances is sprayed onto concrete or onto the surfaces of a concrete mold. However, this approach requires much more robust equipment than is the case with the typical spray application of a water or solvent based surface retardant coating composition. Therefore, it appears to be an economically viable opportunity only for the large precast businesses to follow.

Therefore, a new composition and process are required to achieve high productivity in cement and concrete molding operations where surface retarders are applied to formwork without the use

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of products containing solvents q'iTl I i _ volatile organic chemicals (VOC) in the environment.

SUMMARY OF THE INVENTION

In overcoming the deficiencies of the prior art as described above, the present invention provides a novel composition and method for the manufacture of cast concrete and concrete materials, including precast concrete panels, walls, and other article-shaped structures. and, using a surface retarding agent that prevents the use of VOCs, while improving the productivity of operations where cement and concrete panels and other shaped articles are formed in molds or formwork.

An illustrative retardant composition surface of the invention for cladding or formwork molds such that cement and concrete materials can be cast in forms such as panels or other articles and can be demoulded after. hardening, comprises: a composition for coating a mold or formwork and for removing the cement and the concrete materials molded therein, comprising: a plurality of dry-flowing particles comprising (a) at least one of operational binder of Non-Common Portland Cement (non-OPC) to form a coating when mixed with so

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minus an inert filler and water for fC Liiin r— uniform, said non-OPC binder being present in the amount of 1 to 95 percent, and more preferably 10 to 60 percent; (b) at least one operational inert filler with at least one agile non-OPC primer to form a coating when mixed with water and hardened on the mold or formwork, at least one non-OPC binder that is present in the amount from 0 to 90 percent, and more preferably from 5.0 to 80.0 percent; (c) optionally; at least one accelerating agent operating to accelerate the setting of at least one non-OPC binder, at least one optional non-OPC accelerating agent being present in the amount of 0 to 5.0 percent; and (d) at least one OPC setting retarding agent operative to retard the setting of mold cast or cast concrete or cement, said at least one OPC retarding agent being present in the amount of 0.5 to 4 0.0 percent ; all percentages are based on the total dry weight of the surface retardant coating composition.

The illustrative methods of the invention therefore comprise: mixing previously coating, retardant coating of

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of the surface of a mold or formwork against which the cement or hydratable concrete is cast, the retardant surface coating of the mold surface

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or formwork with composition c

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of? coating, such as by spraying or brushing, and allowing cement or concrete to hydrate and harden in the mold or formwork. Other methods include removing the forged cement or concrete from the mold or formwork, and then removing the surface of the composition from? retarding coating of cement or molded concrete uii 1 lifting pressure.

Can the surface retardant coating compositions of the invention be mixed with water at the construction site, applied onto the surface of a mold using a roller or spray equipment, and can cement or concrete be cast? in the mold within 30-60 minutes. Non-OPC acceleration agents can be used to accelerate the setting of gypsum or other non-OPC binder material in the coating; while an OPC retarding agent works to retard the setting of concrete in the mold so that it can be removed from the mold the next day and its surface can be removed, for example using a high pressure water sprinkler, to reveal embedded aggregate underneath of the removed surface. Other advantages and features of the invention are provided in greater detail below.

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DETAILED DESCRIPTION OF ILLUSTRATIVE MODALITIES ^ '

As outlined above, the present invention provides compositions and methods for providing a surface retardant coating in molds or formwork in which cement or concrete compositions are cast. At least one of the non-Common Portland Cement (non-OPC) binder, such as gypsum, is optionally used, albeit preferably with an inert filler material, as a vehicle for transporting one or more setting retarding agents to retard setting. cement, concrete such as Common Portland Cement (OPC), or other OPC-based hydratable cement composition that is cast in the mold or coated formwork with a surface-retardant coating.

All percentages of the components described or claimed herein with respect to the non-OPC binder containing surface retardant coating compositions are described in terms of percentage ranges based on the total weight of the composition unless indicated otherwise.

The term mold refers to forms shape devices that function to shape OPC cement or concrete hydrate it into panels, decks, paving units, or other construction units; while formwork is essentially a large, boxed mold

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MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY

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with wooden planks and panels, for example, designed for the formation of larger building bridges, such as foundations, walls, tunnels, etc.

The term cement as used herein, means and refers to pastes, mortars, and concrete compositions that are based on Common Portland Cement (OPC) as a hydratable binder. Cement is considered to be hydratable, because it is mixed with water · to initiate the setting of the material in a hardened article such as a wall, panel, or block.

OPC-based cements or cementitious materials employed in the present invention may include supplemental cementitious materials such as limestone, hydrated lime, fly ash, granulated blast furnace slag, pozzolans, 15-nucleosilic, or other commonly included materials to replace a portion of the OPC. The terms paste, mortar and concrete are terms of the technique: pastes are mixtures composed of the OPC-based binder and water; mortars are pastes that include, in addition to fine aggregate (for example, sand); and concrete are mortar, including, in addition, coarse aggregate (for example, gravel: turrada, stone).

Therefore, OPC-based cements, concrete, and other OPC-based hydratable cement compositions 25 in this invention can be formed by mixing the amounts

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required of certain materials, for example, a ta hydrate, water, and fine and / or coarse aggregate, that are applicable to form the particular cement construction structure or article being formed.

The illustrative surface retarding coating compositions of the invention, therefore, are based on the use of a non-OPC cementitious material, optionally but preferably with an inert filler, For carrying one or more OPC setting retarding agents and the non-OPC cementitious material it is preferably used with a setting accelerator which facilitates the hardening of the non-OPC coating composition after it is mixed with water and applied. a Surface of the mold or formwork. The surface retarding coating composition, after mixing with water, can be applied using spray equipment, coarse or fine brush, or manually trowel or flush

An illustrative surface retardant coating composition of the invention for the lining of a mold or formwork and demoulding of hydrated cement compositions (such as mortar or concrete) cast therein, comprises a plurality of dry-flowing particles which include but are not limited to the following: (a) at least one of Portland Non-Common Cement (non-OPC) operating binder to form a coating when mixed with

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at least one inert filler and water to form a mixture in the amount of from 1 to 95 percent, and more preferably from 10 to percent at least, attached load with at least one non-OPC binder to form a coating when mixed with water and cast or form, at least one non-OPC binder than 90 percent, and more preferably 5-80 percent;

(c) optionally, although accelerating the setting of at least non-OPC accelerator agent at least one of them present in a 5.0 by setting retarder

OPC to retard setting of formwork concrete, the retarding agent of at least one OPC that is present at 40.0 percent. All percentages set forth in this document are based on the

Those of the non-OPC binder retardant coating composition that are contemplated for use in the present invention include calcium sulfate (eg, gypsum), alumina cement, suifoalumine cement, aluminosilicate, lime blends with a non-crystalline siliceous material in powder form, and mixtures

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thereof. A preferred non-OPC binder material fi'dcv-&gt; is gypsum. The plaster can be of alpha or beta grade. For example, alpha grade gypsum is typically used as a casting gypsum and beta is used as gypsum construction (see eg ES 132 79-1). When gypsum is used as a non-OPC binder, gypsum may be present in the coating composition in the amount of 1-95%, more preferably 10-60%, and more preferably 10-4 0%, based on dry weight total coating composition.

Illustrative aluminosr1 and cato materials that can also be used as the non-OPC binder material, which: can be used in combination with gypsum (or not), include ash, bottom ash, volcanic glass, natural pozzolana, metakaolin, Granulated blast furnace slag, red mud, calcined and raw clays and shale, diatomaceous earth, zeolite, and mixtures thereof.

Other illustrative materials contemplated for use as the non-OPC binder for the purposes of the present invention include a mixture of lime powder with non-crystalline siliceous by-products of: metal production of: silicon or ferrosilicon allows, silica flour, ash husk: rice., silica flour, or combinations of: the same.

Examples of: inert fillers that are used in combination with the non-OPC binder include carbonate from the MEXICAN institute

OF THE FRORIEDAI

INDUSTRIAL calcium, silica, barium sulfate, talc, mica, or a mixture thereof. The use of calcium carbonate is preferred. The amount of inert filler 0.0 to 90.0 percent, and more preferably 5.0 to 80.0 percent, based on the total dry weight of; the coating composition.

Optionally, but preferably, the surface retarding coating composition of the invention includes at least one setting accelerating agent to accelerate the setting or hardening of the η or -OPC binder material 1 (eg, gypsum). Preferred non-OPC sets can be selected from anhydrites, gypsum, potassium, sodium sulfate, iron sulfate, sodium chloride chloride, magnesium chloride, ammonium chloride, fluorinated salt, nitrite, nitrate, formate, acetate, chloride, thiocyanate, or mixtures thereof. When gypsum is used as a non-OPC binder, the use of gypsum is preferred. Sodium benzoate, calcium nitrite, calcium nitrate, and mixtures thereof are known to have resistance against corrosion, and may be preferred where molds or formwork are made of metal. Non-OPC setting agents or composition acceleration agents can be used as a coating in the amount of 0.0 to

5.0 percent, based on the total composition of the coating composition.

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MEXICAN INSTITUTE OF PROPERTY iwnusTRiAi. ^ * 7 Invention contemplates the use of at least one 3-set OPC setting agent.

Therefore, suitable OPC setting retarding agents include crafty sucrose, fructose, lactose, glucose, maltose, xi slab, dextrose, arabinose, molasses, sucrose, a borate, a phosphate, a phosphonate, a zinc salt, a hydroxycarboxylate , an organic acid or salt thereof, an organic acid ester or salt thereof, or mixtures thereof. Preferred among organic salts used as OPC setting retarding agents of the present invention are citrate, tartrate, gluconate, malate, glutamate, and mixtures thereof. Preferred among the organic salt esters used as OPC setting retarding agents are diethyl tartrate and triethyl citrate. Other organic salt esters believed to be suitable for this use can also be found in the

World Patent Application No. 2010/020857 Al, owned by the common assignee thereof. Said at least one OPC setting retarding agent is preferably used in illustrative surface retarding coating compositions of the invention in the amount of 0.5 to 40.0 percent based on the total dry weight of the composition.

In other illustrative surface retardant coating compositions of the invention, certain retarding agents should be avoided which could affect

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MEXICAN INSTITUTE OF LA PILOMELía: INDt'TrpL'l negatively binding material non-OPC parvo forge.

Non-OPC is gypsum, the following retarding agents must ico, succinic acid, malic acid, gluconic acid, tartaric acid. Therefore, preferred coating compositions comprise gypsum as the non-OPC binder material, but are devoid of the aforementioned retarders.

Exemplary surface retarding coating compositions of the invention include one or more additional additives, such as thickeners, resins, colorants, dispersants, antifoaming agents, and corrosion inhibitors (when using 1-to-1 molds). formwork).

Suitable thickening agents that could help achieve a desired rheology for better application include polysaccharide biopolymers such as diutane gum, welan gum, and xanthan gum, as well as cellulose derivatives, guar gum, and starch. Other water soluble or dispersible resins could be used as polyvinylpyrrolidones, polyvinyl alcohols, or emulsion resins (dried). Cellulosic derivatives are also preferred. Thickeners can be used in surface retardant coating compositions in the amount of 0.0 to 10.0 percent, more preferably 0.5

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3.0 percent, based on composition dry weight is coated.

Examples of resins, which could be used to improve the abrasion resistance of surface retardant compositions, when applying formwork, include air resins, vinyl resins, styrene-butadiene resins,

The preferred amount of resin is 0.0 to 2 0.0 and more preferably 0.0 total dry weight of the surface retardant coating composition.

Illustrative colorants include pigments known and conventionally used in paints and gypsum formulations for light blocking and / or to provide visual distinction in the final product.

include, but are not chromium, titanium dioxide, similar oxides. The dyes are composed

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Iron, oxide can be used in surface retardant coating at 15.0 percent, and more preferably percent, based on the total dry weight of that of the surface retardant coating composition.

As mentioned above, corrosion inhibiting agents can be incorporated into the retardant composition of the surface to be coated on

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steel. Agents are suitable for this purpose, with setting of the material capacity of the formwork agent.

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'tn-ao-cpo ^' to η metal are such that they do not retard non-OPC binder or OPC retard interfere with to retard the against mold or

The retarding coating compositions of the invention incorporate one or more additives to improve the processing properties, such as in the molding or demoulding of shaped cement articles, or to improve the physical properties of the composition that can be incorporated to reduce the Surface tension and retardant composition of on surfaces of co-active agents can

As another example, one or more water repellent materials can be incorporated to reduce the drying time of the surface retardant coating composition when applied as a thin layer on the mold, or formwork (to the extent that do not dry the composition roughly when it is contained in a bucket or bulk container). Repellent materials

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Illustrative water include fatty acid '-' f'ñT 'type materials such as an oleate (eg, butyl oleate), a stearate (eg, butyl stearate), or a mixture thereof.

The surface retardant coating compositions of the invention can be shipped in dry powder form to the precast construction site or plant, and mixed with water in sufficient quantities to initiate hydration of the non-OPC binder material (for example, cast)·; and the coating composition thereafter can be applied, for example, by spray application, on molds or formwork. The coating is expected to set within 30 minutes, and yet the OPC retarding agent will still be operative to retard the setting of cement or concrete that is cast into the mold or formwork. Therefore, the illustrative methods of the present invention for the manufacture of a cement or concrete article, such as a precast concrete article (for example, the panel, block, paver) comprise mixing with water the dry powder composition containing the. non-OPC binder, inert filler, and OPC setting retarder, and other optional ingredients; coating the mold or formwork surface with the surface retarding coating composition, such as by spray application; and allowing cement or concrete to hydrate. Others

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Steps involve removing the mold or formwork from the concrete or concrete, thereafter removing the retardant coating composition from the surface of the cement or cast concrete using pressurized water, such as water sprayed through a nozzle.

Although the invention is described herein using a limited number of embodiments, these specific embodiments are not intended to limit the scope of the invention as otherwise described and claimed herein.

modi fi camones variations of the described modalities.

More specifically, they are given as a specific fashion instruction of the claimed invention. It should be understood that the invention is not limited to the specific details set forth and η 1 st examples.

EXAMPLE 1

The following illustrative formulation will provide a retardant coating surface composition with excellent drying time, adhesion resistance, and other excellent performance characteristics when used to obtain aggregate concrete surfaces.

<td>exposed</td><td>plaster</td><td> (26 %);</td><td>cast</td><td>(0.15%); thickener</td>

<td>colulós i</td><td>co (i. 3%);</td><td>dextrose (</td><td> 2 %) ;</td><td>and calcium carbonate</td>

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components were mixed to provide a non-harmful powdered product. Next, ostia mixture was mixed with water in a ratio of 100 g. of powder to 150 g. of water, and is applied using the roller on the surface of the mold, at a speed of 100-150 g / m². Curing time lasts. about 30 minutes (assuming the temperature between +5 to + 40 ° C), and the coated mold is ready to receive the molten concrete, which was allowed to cure overnight. The next day, the concrete is removed from the mold, and the aggregates embedded in it. Concrete is developed with a high pressure jet of water to remove the surface of the concrete that was in contact with the surface retardant coating (having active OPC setting retarder contained therein). The engraving obtained is approximately 3-6 mm deep (and the depth will depend on the design of the concrete mix).

EXAMPLE 2

The following example is similar to the coating composition in Example 1 above, but was designed to achieve uni? slightly decreased engraving depth (2-4 mm). The following components were mixed together to provide the surface retardant coating composition (in the form of a powder product): Plaster (26%); plaster (0.1%); cellulosic thickener (1.3%); lactose

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(2 %); and calcium carbonate (mean particle size of

EXAMPLE 3

The following example is similar to the coating composition in Example 1 above, but was designed to achieve a slightly decreased engraving depth (6-10 mm). The following components were mixed together to provide the surface retardant coating composition (in the form of a powder product): alumina cement (Kerneos Terna! White) (26%); cellulosic thickener (0.5%); sucrose (5%); and calcium carbonate (average particle size of 15 microns (68.5%).

The present invention is not limited by the examples and illustrations above, which are provided for illustrative purposes only.

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