Based on fly ash light-weight cementing composition with high compressive strength and fast setting. RU patent 2513813.

FIELD: chemistry.

SUBSTANCE: invention relates to method of manufacturing fast setting light-weight cementing composition with improved compressive strength for building products such as panels. Method of obtaining light-weight cementing mixture, which has improved compressive strength and resistance to water, includes mixing water, cementing reacting powder, alkali metal salt of citric acid as set accelerator and light-weight filling agent, where weight ratio of water to reacting powder constitutes approximately 0.17-0.35:1.0, reacting powder includes 75-100 wt % of sol dust, which contains at least 50 wt % of fly ash of class C and 0-25 wt % of hydraulic cement and/or gypsum, setting of cementing mixture being achieved within from 4 to 6 minutes of composition mixing without addition of set retarder. Invention also deals with composition for obtaining light-weight cement panel.

EFFECT: obtaining light-weight cementing mixture, which has improved compressive strength and stability.

10 cl, 9 dwg, 9 tbl

Cross reference to related application

[001] is a Stated priority of the patent application, US no 12/237,634, filed September 25, 2008, incorporated herein by reference in its entirety.

The scope of the invention

[002] the invention as a whole is concerned fast-setting cement compositions, which can be used in some applications where it is desirable rapid hardening and achieving early strength. In particular, the invention relates to the cementing of tracks that can be used for manufacturing the panels with excellent moisture resistance for use in wet and dry locations in buildings. Precast concrete products such as cement panel, made under conditions which ensure quick setting cement mixture so that the panel can be processed shortly after cementing mixture cast in stationary or moving the form or continuously moving tape. Ideally, this setting cement mixture can be reached in approximately 20 minutes, preferably for 10-13 minutes, preferably for 4-6 minutes after mixing cement mixed with appropriate amount of water.

Background of the invention

[003] US Patent 6869474, Perez-Turnip et al., included in this document by reference, discusses extremely fast setting cementitious compositions for the production of products based on cement, such as cement panel, made by adding alkanolamine to hydraulic cement, such as Portland cement, and the formation of suspension water under conditions that provide an initial temperature of the suspension of at least 90 degrees Fahrenheit (32 degrees Celsius). May include additional reactive materials such as cement with high content of aluminum oxide, calcium sulfate and pozzolanic material such as fly ash. Extremely quick setting allows quick receipt of cementitious products. Found that triethanolamine supplements are very strong accelerator that can produce compounds with relatively short final setting time with elevated levels of fly ash and gypsum, and without the need for calcium aluminate cements, including calcium aluminate. However, compositions with triethanolamine also had a relatively lower early compressive strength compared with that of the cement panels that contain calcium aluminate cements.

[004] pending patent application, US no 11/758,947, filed June 6, 2007 .Perez-Turnip et al., included in this document link, discusses extremely fast setting cementitious songs from early compressive strength for the production of products based on cement, such as cement panel, achieved by adding alkanolamine and phosphate to a hydraulic cement, such as Portland cement, and the formation of slurry with water under conditions that provide an initial temperature of the suspension of at least 90 degrees Fahrenheit (32 degrees Celsius). May include additional reactive materials such as cement with high content of aluminum oxide, calcium sulfate and pozzolanic material such as fly ash. In addition, all songs contained a significant number of hydraulic cement and gypsum.

[005] US Patent 4488909, Galer et al., included in this document by reference, discusses cementing composition, is able to harden quickly. Compositions allow obtaining high speed resistant carbon dioxide cement panels by forming essentially all of the potential ettringite in approximately 20 minutes after mixing the composition of water. The main components of cementing songs are the Portland cement with high content of aluminum oxide, calcium sulphate and lime. Can be added pozzolana, such as fly ash, montmorillonite clay, diatomaceous earth and pumicite, to approximately 25%. Cement composition includes approximately 14-21 weight.% cement with high content of aluminum oxide, which in combination with other components makes it possible to quick formation of ettringite and other calcium aluminate hydrates responsible for quick setting cement mixture. In this the invention Galer et al. presented using aluminates high alumina cement (US) and use of sulfate ions plaster for the formation of ettringite and achieve quick setting cementing their mixture.

[006] Ettringite is a calcium aluminium sulphate connection with the formula Ca 6 Al 2 (SO 4 ) 3 * N 2 O or alternative 3 CaO * the Al 2 O 3 * the 3CaSO 4 * the 32H 2 O. Ettringite is formed in the form of a long needle-like crystals and provides rapid early hardening cement panels so that they can be processed shortly after low tide in the form or continuous cast and forming the tape.

[007] In General, fast-setting part for Galer et al experiencing some limitations. These restrictions, as shown below, are even greater problems in obtaining cementitious products, such as cement panels.

[008] US Patent # 5536310, Brook et al., reveals cementing composition comprising 10-30 parts by weight (pbw) hydraulic cement, such as Portland cement, 50-80 pbw fly ash, and 0,5-8,0 pbw expressed as the free acid carboxylic acids, such as citric acid acid or its salts of alkaline metals, for example, tripotassium citrate or trisodium citrate, with other traditional additives, including retarding additives such as boric acid or borax, which are used to speed up the reaction and time setting songs to overcome the lack unveiled use of the high content of fly ash in cement compositions.

[009] US Patent # 5536458, Brook et al., reveals cementing composition containing hydraulic cement, such as potenzpillen - 80 parts by weight of fly ash and 0,5-8,0 pbw free carboxylic acid such as citric acid or its salts of alkaline metals, for example, potassium citrate or sodium citrate, with other traditional additives, including retarding additives such as boric acid or borax, which are used to speed up the reaction and time setting songs to overcome known lack of use of the high content of fly ash in cement compositions.

[0010] US Patent # 4494990, Harris, reveals cementing the mixture of Portland cement, for example, 25-60 pbw, fly ash, for example, 3-50 pbw, and less than 1 pbw sodium citrate.

[0011] US Patent # 6827776, Boggs et al., reveals hydraulic cement composition, containing Portland cement, fly ash, which is setting time, controlled pH, activator suspension acid, preferably citric acid, and the bases, which can be hydroxide alkaline or alkaline earth metal or salt acid component.

[0012] US Patent # 5490889, Kirkpatrick et al., reveals mixed hydraulic cement, consisting of water, fly ash (50,33-83,63 pbw), Portland cement, crushed silica, boric acid, borax, citric acid (0,04-2,85 pbw) and democraticheskogo activator, for example, of lithium hydroxide (LiOH) or potassium hydroxide.

[0013] US Patent # 5997632, Styron, reveals hydraulic cement composition comprising 88-98% wt. fly ash, 1-10% wt. Portland cement and from approximately 0,1-4,0% wt. citric acid. Lime to achieve the desired minimum content of lime 21% provided subbituminous ash dust or subbituminous ash dust in combination with enriching tool. In addition to citric acid Styron applies alkaline source, such as potassium or sodium hydroxide.

[0014] The final setting time cementing mixtures of products prior art is typically more than 9 minutes and can be extended for up to 2-3 hours for standard concrete products. The final setting time is usually defined as the time during which cementing mixture seize, during which concrete products made from them can be processed and are located one above the other, although the chemical reaction can last for extended periods.

[0015] Amount of cement with high content of aluminum oxide (also known as calcium aluminate cement) in the reacting mixture of powder in the concrete products prior art is also very high. Typically, cement with high content of aluminum oxide is more than 14% wt. the reacting mixture of powder.

Short description of the invention

[0016] the Purpose of this invention is to provide the method of making fast-setting cement slurry.

[0017] Another purpose of this invention is to provide lightweight cement compositions with improved early and final compressive strength. Cementing songs contain potassium citrate, sodium citrate or their mixtures.

[0018] the invention includes a way to provide a lightweight cement mixture with fast setting, improved compression strength and resistance to water, including: mixing with environmental or higher ambient temperatures, water reactive powder, accelerating setting the number of salts of alkaline metal citric acid and lightweight filler, where the ratio of water to solid substances reacting powder is about 0,17-0,35:1,0 or more, preferably about 0,20-0,23:1,0 reacting powder includes 75-100% wt. ash dust and 0-25% wt. hydraulic cement and gypsum.

[0019] Preferably reacting powder does not contain hydraulic cement and gypsum (hydrated calcium sulphate).

[0020] Such cementing reacting powder include, at a minimum, fly ash, and may also include hydraulic cement, for example, Portland cement or calcium aluminate cement (CAC) (also commonly called alumina cement or cement with high content of aluminum oxide), calcium sulphate and not containing fly ash mineral Supplement.

[0021] Up to 25% wt. mixture cementing reacting powder cementing songs can be not containing fly ash mineral additives with large, small cementing properties or not with cementitious properties.

[0022] Cementing reacting powder in General contains approximately 10-40% wt. lime and more typically 20-30 wt% lime. However, the addition of lime are not required for quick setting, if the ingredients are reacting powder already contain enough lime. For example, Type With fly ash generally contains lime. Thus, the reacting mixture of cementitious powder compositions typically does not contain added from the outside lime.

[0023] Typical suspension has an initial temperature from room temperature to about 100 degrees F-115 F (24C to approximately 38o -46 C).

[0024] Final setting time (i.e. the time after which cementing panel can be processed) cementitious composition, measured according to the needle Gilmore, should be at most 20 minutes, preferably 10-13 minutes or less, preferably approximately 4-6 minutes after mixing with an acceptable amount of water. The shorter the time of setting and more high early strength on compression helps to increase output and reduce the cost of manufacturing the product.

[0025] Very fast-setting cement compositions of this invention can be used for a number of applications where it is desirable rapid hardening and achieving early strength. The use of salts of alkaline metal citric acid, such as potassium citrate and/or sodium citrate, to accelerate the setting cementitious composition, when the suspension is formed at elevated temperatures, makes it possible increased speed of receipt of cementitious products, such as cement panels.

[0026] Dosage citrate alkali metal suspension is preferably in the range of approximately 1.5-6 wt.%, preferably approximately 1,5-4,0 wt.%, more preferably approximately 2-3,5 wt.%, and it is most preferable to approximately 3.5 weight% based on cementitious reactive components of this invention. Potassium citrate or sodium citrates are preferred. As mentioned above, these weight percentages based on 100 parts by weight of reactive components (cement reacting powder). Thus, for example, 100 pounds cementing reacting powder can be approximately 1,5-4,0 total pounds of potassium and/or sodium citrate.

[0027] Typical cementing reacting powder of the present invention includes 75-100% wt. fly ash and 0-25% wt. hydraulic cement, such as Portland cement or plaster. Typically, at least half of fly ash is Type With ash dust.

[0028] Another typical cementing reacting powder includes 75-100% wt. fly ash, 0-20% wt. calcium aluminate cement, 0-7% wt. calcium sulphate based on the weight of reacting powder, does not include gypsum and does not include hydraulic cement, other than calcium aluminate cement.

[0029] There is a synergistic interaction between citrate alkali metal and ash dust. The addition of salts of alkaline metal has advantages achieve increase of early and long-term durability on compression for compositions containing high quantities of fly ash in comparison with comparable arrangements, using accelerators like calcium aluminate cements the, triethanolamine or caustic alkali metal hydroxides.

[0030] furthermore, the addition of citrates alkali metals improves fluidity mix in comparison with other accelerators, such as aluminium sulphate, which can lead to premature solidification concrete mixes.

[0031] there may be other additives, for example, inert filler that are not considered cementing reacting powder, but are part of the total cement compositions. Such other supplements include one or more of sand, filler lightweight aggregates, reducing water tools such as superplasticizers, accelerating the setting means that slow down the setting of funds, involving air tools, foaming equipment, compression control, means of modifying the suspension viscosity (thickening), painting tools and internal hardening tools that can be included as desirable depending on the possible ways and application of cementitious compositions of the present invention.

[0032] Lightweight cement compositions of the present invention can be used for precast concrete construction products such as cementing panel with excellent moisture resistance for use in wet and dry locations in buildings. Precast concrete products such as cement panel, making under conditions which ensure quick setting cement mixture so that the panel can be processed immediately after low tide cementing of the mixture in stationary or moving the form or continuously moving tape.

[0035] FIGURE 1 is a graph of the results of Example 1, showing the effect of increasing sodium citrate degree temperature increase for mixtures with brown, boric acid and citric acid.

[0036] FIGURE 2 is a graph of the results of Example 1, showing the effect of increasing sodium citrate on the temperature increase for mixtures with boric acid and citric acid.

[0037] FIGURE 3 is a graph of the results of Example 2, showing the effect of increasing the potassium hydroxide on the temperature increase for mixtures with citric acid and sodium citrate.

[0038] FIGURE 4 is a graph results of Example 4 shows the temperature increase for mixtures with potassium citrate without potassium hydroxide.

[0039] FIGURE 5 is a graph of the results of Example 5 shows the temperature increase for mixtures containing potassium citrate or sodium citrate, mixed with water at room temperature.

[0040] 6 is a graph of the results of the Example 8 shows the temperature increase for mixtures containing different ratios of fly ash and Portland cement type III, using the weight ratio of water-to-cement-0,30:1.

[0041] 7 is a graph of the results of the Example 9 showing the effect of temperature rise for mixtures 1-4 in this example with various parities of water to ash dust without Portland cement.

[0042] PIG is a graph of the results in Example 9, showing the temperature increase for mixtures 3, 5, 6, and 7 for mixtures with different ratios of fly ash and Portland cement type III citrate at a weight ratio of water to the combined weight of the fly ash and Portland cement 0,20:1.

[0043] FIG.9 is a graph of the results of mixtures Example 10 different doses of potassium citrate, using only fly ash without Portland cement, and shows that adding potassium citrate significantly increases the degree temperature increase is based on fly ash mixtures.

A detailed description of the invention

[0044] the invention includes a way to provide a lightweight cement mixture with improved compression strength and resistance to water including: mixing water reacting powder, salt, alkali metal citric acid and lightweight filler, where the ratio of water to solid substances reacting powder is about 0,17-0,35:1,0, typically about 0,17-0,30:1,0, preferably approximately 0,2-0,23:1,0. Reacting powder includes 75-100% wt. fly ash and 0-25% wt. hydraulic cement and/or plaster. Typical mixture of the present invention cementing reacting powder include fly ash with potassium citrate and/or sodium citrate and water at the initial temperature of the suspension from, at least room temperature up to 115 degrees F (24 C to 41 degrees C) to exit quick setting and preferably less than 10-13 minutes, preferably approximately 4-6 minutes or less.

[0045] the invention also provides cementing compositions with improved characteristics quick the final setting and improved early compressive strength.

[0046] Typical ingredients are presented in the following table A.

Ingredient

Wide parts based on dry weight at 100 parts reacting powder

Preferred parts based on dry weight at 100 parts of reacting powder

Preferred parts based on dry weight at 100 parts reacting powder

Reacting

100 parts

100 parts

100 parts

88,5-100

Portland cement

less than 5

approximately 0

less than 5

approximately 0

aluminate cement

less than 2

approximately 0

Calcium sulfate

less than 2

approximately 0

less than 25

less than 25

Not containing fly ash mineral Supplement added lime

optional*

salt alkali metal citric acid

lightweight filler

not containing fly ash mineral Supplement

less than 25

less than 11,5

zamedlitel shvatyvanija

the means of exciting the air

secondary inorganic accelerator shvatyvanija

less than 1

less than 0.25

less than 0.1

superplasticizer

controls compression, painting tools, tools, modifying viscosity (thickening) and internal hardening tools

* add lime is not required if the ingredients are reacting powder already contain enough lime.

[0048] overall, the weight ratio of water to cementing reacting powder is approximately 0,15-0,3:1,0. Inert lightweight fillers are not part of cementing reacting powder.

[0049] without going into specific theory, theoretically predicted that the increase of the early period and compressive strength is achieved with fast shvatyvanie by providing cementing reacting powder with a high mineral content of ash dust 75-100% wt. and preferably without Portland cement or calcium aluminate cement or gypsum, and mixing cement reacting powder, citrate alkali metal and water to form a slurry at elevated temperatures above 20 C so that the formation of alkaline silica-alumina hydrate, and/or hydrate aluminosilicate, and/or compounds of calcium silicate, presented in fly ash, can occur as a result of hydration this mixture reacting powder citrate alkali metal.

[0050] Thus, a reasonable amount of water provided for the hydration of cement reacting powder for quick formation of alkaline silica-alumina hydrate and other hydrates present in fly ash. In General, the quantity of added water is more theoretically required for the hydration of cement reacting powder. Such high content of water facilitates the applicability of cementing suspension. Typically, in suspension weight ratio of water to the mixture reacting powder is about 0,20-0,35:1, more typically about 0,20-0,30:1, preferably about 0,20-0,23:1. The amount of water depends on the needs of the individual materials present in the cementing of the composition.

[0051] Alkaline alumosilicate hydrates, and/or other silicate hydrates, and/or aluminosilicate calcium compounds are formed very quickly in the process of hydration, therefore, giving quick setting and hardness mixes, made with a mixture of cementing reacting powder compositions of the present invention. In the manufacture of products based on cement, such as cement panel, initially there is a formation of alkaline silica-alumina hydrate, and/or other silicate hydrates, and/or aluminosilicate calcium compounds that make possible the processing of cement panels for a few minutes after mixing cement composition of the present invention with an acceptable amount of water.

[0052] Grasp of composition is characterized by a start and end time of setting, measured with the use of needles Gilmore, described in the procedure test ASTM C. The final setting time also corresponds to the time when concrete product, for example a concrete panel, acquires sufficient strength so that it can be processed or transported, in the case of the concrete floor or road. Relatively higher the early period (3-5 hours) compressive strength can be an advantage for concrete material, because it can withstand higher load without deformation. The specialist in this area will be clear that the curing reaction last long periods after reaching the final setting time.

[0053] Early strength of the composition is characterized by measurement of the compressive strength after 3-5 hours hardening, as defined in ASTM C. Achieving high rapid hardening allows easy handling located one above the other panels.

Cementing reacting powder

[0054] Cementing reacting powder contains fly ash and the optional not containing fly ash mineral supplements, hydraulic cement and its optional plaster. Cementing reacting powder is typically contains 75-100% of fly ash and 0-25% wt. the component selected from the group comprising hydraulic cement, gypsum and not containing fly ash mineral supplements. Cementing reacting powder preferably contains 88,5-100% wt. fly ash. Cementing reacting powder contains more preferable 88,5-100% wt. fly ash and does not contain the hydraulic cement and gypsum.

[0055] Preferably cementing reacting powder contains 10-40% wt. lime. However, this lime as a whole is not added lime. Preferably it is included in another ingredient cementing reacting powder, for example, fly ash.

[0056] Main ingredient cementing reacting cementitious powder compositions of the present invention is an containing fly ash mineral Supplement preferably Type With fly ash. Fly ash is described below in the section titled Containing fly ash and not containing fly ash mineral supplements.

[0057] In addition to fly ash cement reacting powder may include 0-25% wt. optional cementing additives, such as Portland cement, calcium aluminate cement, calcium sulphate or plaster (natural gypsum). However, cementing song with a lower water content of the present invention, i.e. cement composition with weight ratio of water to reacting powder about 0,17-0,35:1.0 these optional cementing additives have significantly reduced compressive strength in comparison with the same songs with a lower water content of the present invention without additional cementing additives.

[0059] Hydraulic cement traditional compositions reacting powder mostly replaced by ash dust with pozzolanic properties, especially Class With ash dust, together with other optional not containing fly ash mineral additives with significant, small or not with cementitious properties. Not containing fly ash mineral supplements with pozzolanic properties are especially preferred in cementing reacting powder of this invention.

[0060] ASTM C-97 defines pozzolanic materials as "silicon or silicon and alumina materials, which themselves have a small cementing value or do not have the discipline value, but will be in a finely powdered form and in the presence of moisture, chemically react with calcium hydroxide in the ordinary temperatures to form compounds with cementitious properties." Various natural and man-made materials called pozzolanic material with pozzolanic properties. Some examples pozzolanic materials include pumice, perlite, diatomaceous earth, thin silica dust, tuff, highways, rice husks, metakaolin, ground granulated blast furnace slag and fly ash.

[0061] All of these pozzolanic materials can be used either alone or in combined form as part of cementing reacting powder of this invention.

[0062] Fly ash are the preferred pozzolan in cementing the reacting mixture of powder of the present invention. Types of fly ash containing high amounts of calcium oxide and calcium aluminate (such as Class C fly ash ASTM C standard), are preferred, as explained below. Other mineral additives such as calcium carbonate, vermiculite, clay and crushed mica, may also be included as mineral supplements.

[0063] fly Ash is a fine powder by-product formed from the combustion of coal. Power plants boilers, burning crushed coal, produce most of the commercially available types of fly ash. These types of fly ash consist mainly vitreous spherical particles and residues of hematite and magnetite, charcoal and some crystalline phases formed during cooling. The structure, composition and properties of fly ash particles depend on the structure and composition of coal and combustion processes, which is formed fly ash. ASTM C standard distinguishes between two main classes species of fly ash for use in concrete Class C and Class F. These two classes species of fly ash as a whole come from different types of coal, which are the result of differences in the processes of formation of coal that occur during the geological periods. Class F fly ash is usually formed during the combustion of coal or bituminous coal, whereas Class C fly ash is usually generated from lignite or polivitaminnoe coal.

[0064] ASTM C standard distinguishes Class F and Class C fly ash mainly on their pozzolanic properties. Accordingly, in ASTM Is the main standard specification difference between Class F fly ash dust and Class C fly ash dust lies in the minimum limit of SiO 2 +Al 2 O 3 +Fe 2 O 3 in the composition. The minimum limit SiO 2 +Al 2 O 3 +Fe 2 O 3 for Class F fly ash is 70%and for Class C fly ash is 50%. Thus, the species of the Class F fly ash more pozzolanic than the species of the Class C fly ash. Although details are not defined in ASTM C standard, Class C fly ash dust typically have a high content of calcium oxide (lime).

[0065] Class C fly ash generally has a cementing properties in addition to the pozzolanic properties because of free lime (calcium oxide), while the Class F is rarely cementing, when mixed with water separately. The presence of high concentration of calcium oxide gives kinds of Class C fly ash cementing properties that leads to the formation of calcium silicate and calcium aluminate hydrates when mixed with water. As will be seen in the examples below, Class C fly ash as found, provides the best the results, especially in the preferred compounds, which are not used calcium aluminate cement and gypsum.

[0066] Typically, at least 50% wt. fly ash in cement reacting powder is Type With ash dust. Typical, at least 75% wt. cementing reacting powder is Type With ash dust. Even more preferably at least 88,5% wt. cementing reacting powder is Type With ash dust.

[0067] Typical minerals identified in the fly ash are quartz (Si02), mullite (Al 2 Si 2 O 13 ), helenit (Ca 2 Al SiO 2 7 ), hematite (Fe2O3 ), magnetite (Fe 3 O 4 ), among others. In addition, fly ash also revealed polymorphic minerals aluminum silicate, usually found in rocks, such as sillimanite, kyanite and andalusite, all three presents the molecular formula Al SiO 2 5 .

[0068] Typical acceptable Class C fly ash obtained from polivitaminnoe coal, has the following composition is given in table Century

[0070] fine grain ash dust typically is such that less than approximately 34% retained on the sieve 325 mesh (number of States), as tested to ASTM test procedure With-311 ("Sampling and Testing Procedures for Fly Ash as Mineral Admixture for Portland Cement Concrete"). This fly ash preferably extracted and used dry, due to its self-setting nature.

Hydraulic cement

[0071] fly Ash associates, mainly, all cementitious material reacting powder of this invention. In some cases, reacting powder may also include optional cementing additives, such as hydraulic cements, or can be added plaster. However, these optional cementing additives are not preferred because they reduce the ultimate compressive strength songs lightweight filler of this invention.

[0072] Hydraulic cements are materials that seize and harden after combining with water as a result of chemical reactions mixed with water, and which after hardening keep durability and stability even under water. Portland cement is a typical hydraulic cement. It should be understood that, as used herein, "hydraulic cement" does not include plaster, which does not add strength under water, although typically a number of gypsum include in Portland. Specification ASTM C 150 standards for Portland cement defines Portland cement as a hydraulic cement, obtained by grinding of clinker, consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an additive for crushing.

[0073] For manufacturing Portland cement homogeneous mixture of limestone and clay burned in a furnace for the formation of Portland cement clinker. The following four main phases present in Portland clinker-tricalcium silicate (3CaO * the SiO 2 , also known as C 3 S), dicalcium silicate (2CaO * the SiO 2 , called C 2 S), tricalcium aluminate (3CaO * the Al * the Al 2 O 3 or 3 (a) and tetracaine of almaterra (4CaO * the Al 2 O 3 * the Fe 2 O 3 or 4 C AF). Educated clinker, containing the said compounds, are crushed with calcium sulfates to the desired fineness to obtain Portland cement.

[0074] Other compounds present in small quantities in the Portland cement include double salts of alkali metals sulfates, calcium oxide and magnesium oxide. When the cement panels should be made of Portland cement, Portland cement will typically have the form of very small particles so that the particle surface area of more than 4000 cm 2 /g and typically 5000-6000 cm 2 /gram, how measured method of measurement surface area of blaine (ASTM With 204). Of the various recognized classes Portland cement ASTM Type III Portland cement is the most preferable in cementing reacting cementitious powder compositions of the present invention. This is because of its relatively more rapid reactivity and development of high rapid hardening.

[0075] In this invention avoids the need for hydraulic cement-like Type III Portland cement, and relatively rapid development of the early strength can be obtained using only fly ash instead of mixtures containing Type III Portland cement. Other recognized types of cement that are not needed in the composition of the present invention, consist of Portland cement Type I or other hydraulic cements, including Type II Portland cement, white cement, slag cement, such as cement from blast furnace slag, and pozzolanic blended cements, expanding cement, calcium sulfoaluminate cements and well cements.

Calcium aluminate cement

[0076] Calcium aluminate cement (CAC) is another type of hydraulic cement, which can form a component of a mixture of reacting powder some embodiments of the present invention, when not require a higher compression strength, suspensions with a low water content, including significant quantities of fly ash.

[0077] Calcium aluminate cement (CAC) are also commonly called alumina cement or cement with high content of aluminum oxide. Calcium aluminate cements have a high content of aluminum oxide, typical is approximately 36-42 wt.%. Also commercially available calcium aluminate cements with higher purity, in which the content of aluminium oxide can reach 80 wt.%. These calcium aluminate cements with higher purity tend to have high cost in comparison with other cements. Calcium aluminate cements used in the compositions of some embodiments of the present invention, finely crushed to facilitate the entry of aluminates in the aqueous phase so that can happen fast formation of ettringite and other calcium aluminate hydrates. The surface area of calcium aluminate cement, which can be used in some variants of implementation of the composition of the present invention will be more than 3000 cm 2 /g and typically about 4000-6000 cm 2 /gram, how measured method of measurement surface area of blaine (ASTM With 204).

[0078] there are some ways of manufacture for production of calcium aluminate cement. Typically, the main raw materials used in the manufacture of calcium aluminate cement, are bauxite and limestone. The following describes one method of production, which is used in the U.S. for the production of calcium aluminate cement. A number of bauxite extraction of ore is first crushed and dried and then milled together with limestone. Dry powder that include bauxite and limestone, then fed into the rotary kiln. Shredded low-ash coal is used as fuel in the furnace. In the furnace is a reaction between bauxite and limestone, and the molten product is collected in the lower end of the kiln and poured in the gutter mounted on the bottom. Molten clinker extinguish with water to form granules of clinker, which is then transported to a pile of raw materials. Such chips are then milled to the required fineness for the production of the final cement.

[0079] Some of calcium aluminate compounds are formed during the process of manufacture of calcium aluminate cement. The predominant compound is molded of mono calcium aluminate (Cao * the Al 2 O 3 , also known as SA). Others formed calcium aluminate-calcium silicate compounds include CaO * the 7l 2 Of 3 , also known as 12 And 7 , CaO * the 2Al 2 O 3 , also known as SA 2 , dicalcium silicate (2CaO * the SiO 2 , named C2S), dicalcium alumina silicate (ZAO * the Al 2 O 3 * the SiO 2 , named C 2 AS). Also formed some other compounds containing a relatively high proportion of iron oxides. They include calcium ferrites, such as CaO * the Fe 2 O 3 , or CF and 2CaO * the Fe 2 O 3 , or C 2 F, and calcium alumotantite, such as teracalorie of almaterra (4CaO * the Al 2 O 3 *Fe 2 O 3 or 4 C AF), 6CaO * the Al 2 O 3 * the 2Fe 2 O 3 or 6 C AF 2 ) and 6CaO * the 2Al 2 O 3 * the Fe 2 O 3 or C 6 A 2 F). Other minor ingredients present in calcium aluminate cement, include magnesium oxide (MgO), titanium oxide (TiO 2 ), sulphates and alkalis.

Calcium sulfate

[0080] Different forms of calcium sulfate, as shown below, can be used in the present invention to provide sulfate ions to form ettringite and other calcium sulfoaluminate hydrated compounds:

[0081] Dehydrate - CaSO4 * the 2H 2 O (commonly known as gypsum or natural gypsum).

[0082] Hemihydrate - CaSO4 * the 2H 2 O (commonly known as plaster or plaster, or just gypsum).

[0083] Anhydrite - CaSO 4 (also known as anhydrous calcium sulfate).

[0084] Natural gypsum is the plaster with a relatively low purity and is preferred for economic reasons, although they can be used more high-purity grade. Natural plaster made from mined gypsum and reduced to a relatively small particles so that the specific surface area is more than 2000 cm2 /g and typically about 4000-6000 cm 2 /gram, how measured method of measurement surface area of blaine (ASTM With 204). Small particles can easily dissolve and get gypsum, necessary for formation of ettringite. Synthetic gypsum, obtained as a by-product of various industries, can be used as the preferred calcium sulfate in that invention. The other two forms of calcium sulfate, namely the hemihydrate and anhydrite, can also be used in the invention, instead of plaster, i.e. digitalnoj form of calcium sulphate.

Alkali salts of citric acid

[0085] In this invention the use of alkaline metal salts of citric acid, such as sodium or potassium citrate, gives mixture with a relatively high flow, which does not freeze too quickly, i.e. not freeze faster 5-10 minutes after mixing at temperatures above room temperature, whereas achieved good early compressive strength.

[0086] Dosage salts of alkaline metal citric acid, for example, potassium citrate or sodium citrate, is about 1.5 to 6.0 wt.%, preferably approximately 1,5-4,0%wt., more preferably approximately 2.0 to 3.5 weight% and it is most preferable to approximately 3.5 weight% on the basis of 100 parts cementing reactive components of this invention. Thus, for example, 100 pounds cementing reacting powder can be approximately 1,5-4,0 total pounds of potassium and/or sodium citrate. Preferred citrate alkali metals are potassium citrate and sodium citrate, especially tripotassium citrate monohydrate and trisodium citrate monohydrate.

Retarders

[0088] the Main function of the moderator in the composition consists in keeping the suspension mixture from freezing too quickly, thus, provides a synergistic physical interaction and the chemical reaction between the various reacting components. Other secondary effects additives moderator in the song include reduction in the number of superplasticizer and/or water needed to achieve the suspension mixture processed consistency. All of the above effects are achieved due to a false setting suspension. Examples retarding include boric acid, borax, citric acid, potassium tartrate, sodium tartrate and such.

[0089] furthermore, since retarders, warn too fast freezing suspension mixture, their additive plays an important role and is a tool in the formation of good edges during the process of making cement panels. The weight ratio of zamedlitel shvatyvanija to cementing the reacting mixture of powder in General is less than 1.0 wt%, preferably approximately 0.04 to 0.3 wt.%.

[0090] In this invention is revealed that the use of traditional moderator, such citric acid, tartaric acid, malic acid, acetic acid, boric acid, etc. can be avoided by using only alkaline metal salts of citric acid, for example, sodium or potassium citrate, and the use of these citrate alkali metals, in the absence of such traditional moderators setting, it provides good fluidity and prevents too fast hardening concrete suspension.

Secondary inorganic setting accelerators

[0091] As discussed above, the citrates alkali metals are mainly responsible for providing characteristics extremely fast setting and compressive strength, cement mixtures. However, in combination with citrates alkali metals other inorganic accelerators setting can be added as a secondary inorganic accelerators setting in cementing the composition of the present invention.

[0092] it is Expected that the addition of such secondary inorganic accelerators setting gives only a small reduction of the time setting compared to the reduction achieved by the addition of citrate alkali metal. Examples of such secondary inorganic setting accelerators include sodium carbonate, potassium carbonate, calcium nitrate, calcium nitrate, calcium formate, calcium acetate, calcium chloride, lithium carbonate, lithium nitrate, lithium nitrate, aluminium sulphate, alkanolamine, polyphosphates sodium hydroxide, potassium hydroxide, and is similar. The use of potassium hydroxide, sodium hydroxide and calcium chloride should be avoided when a problem corrosion fasteners cement panels. Secondary inorganic accelerators shvatyvanija usually are not necessary. The use of recycled accelerators setting is not required and is not part of the preferred composition of the present invention. In the case of the weight ratio of secondary inorganic accelerator setting to 100 parts by weight of the mixture cementing reacting powder will typically be less than approximately 1.0 wt%, preferably less than approximately 0.25 wt.%. Such secondary inorganic accelerators setting can be used separately or in combination.

[0093] Preferably lithium carbonate and potassium carbonate not apply. Other chemical additives and ingredients

[0094] Chemical additives, such as means of reducing the water content (superplasticizers), can be included in the compositions of the present invention. They can be added to the dry form or in the form of a solution. Superplasticizers help to reduce in a mixture of water demand. Examples of superplasticizer include polynaphthalene, polyacrylates, polycarboxylate, lignosulfonates, mellincollin and such. Depending on the type of superplasticizer the weight ratio of superplasticizer (based on dry powder) to the mixture reacting powder will typically be about 2 weight% or less, preferably approximately 0.1 to 1.0 wt%.

[0095] When it is desirable to get lighter products, such as lightweight cement panel, tools, the breathtaking air (foaming tools), can be added to the song to facilitate product.

[0096] Means, spectacular air add in cementing suspension for the formation of air bubbles (foam) in situ. The means of exciting the air, typically are surface-active substances, used to specifically capture microscopic air bubbles in the concrete. Alternatively, funds, spectacular air, used for externally obtained foam, which is introduced into the mixture compositions of the present invention during the operation the mixing to reduce the density of the product. Typical externally obtained foam mixing tool, a thrilling air (also known as liquid foaming agent), air and water for the formation of foam acceptable in the blowing machine, and then the foam is added to cement slurry.

[0097] Examples of spectacular air/foaming funds include alkyl sulphonates, alkylbenzenesulfonate and alcelaphinae sulfate oligomers among others. Details of General formula such foaming funds can be found in the U.S. patent 5643510, incorporated herein by reference.

[0098] Can be used a tool that captures the air (foaming agent), such as meeting the standards set out in ASTM With 260 "Standard Specification for Air-Entraining Admixtures for Concrete" (Aug. 1, 2006). Tools such breathtaking air, a well-known specialist in this area and described the Kosmatka et al. "Design and Control of Concrete Mixtures," Fourteenth Edition, Portland Cement Association, specifically Chapter 8 entitled, "Air Entrained Concrete," (quoted in the publication of the patent application, US no 2007/0079733 A1). Commercially available breathtaking air materials include winalooy resin, sulfonated hydrocarbons, fatty and resin acids, aliphatic substituted ARYLSULPHONIC, such as sulphonated ligninov salt and a number of other boundary active materials, which usually take the form of anionic or non-ionic surface-active agents, sodium abiyat, saturated or unsaturated fatty acids and their salts, detergents, alkyl-aryl-sulfonates, proletariata, lignosulfonates, tar soap, sodium hidroxistearat, valium, ABS (alkylbenzenesulfonate), LAS (linear alkylbenzenesulfonate), olkonsultant, polyoxyethylene(phenyl) ethers, polyoxyethylene(phenyl)ether sulfate esters or their salts, polyoxyethylene(phenyl)ether phosphate esters or their salts, protein materials, alkenylbenzene, alpha reincorporate, sodium salt alpha reincorporate or sodium laurylsulfate, or sulfonate and their mixtures.

[0099] Typical an exciting air (foaming) tool is approximately 0.01 to 1 wt.% weight of the entire cement compositions.

[00100] Other chemical mixtures, such as controls compression, painting tools, tools, modifying viscosity (thickening)and curing internal funds can also be added in the composition of the present invention, if required.

[00101] Individual fibres of various types can also be included in cementing the compositions of the present invention. The grid made of materials such as polymer coated glass fiber and polymer materials such as polypropylene, polyethylene and nylon, can be used for the reinforcement of the product on the basis of cement, depending on its function and application. Cement panel, received on a given invention, typically reinforced with mesh, made of polymer coated glass fibers.

Fillers and additives

[00102] while open cementing the reacting mixture powder determines quickly grasping component cementitious songs the present invention, a specialist in this area is clear that other materials can be included into the composition depending on its intended use and application.

[00103] for Example, for applications cement panel, it is advisable to obtain a lightweight panel without undue compromise of the desired mechanical properties of the product. This goal is achieved by adding lightweight fillers and additives. Examples of useful lightweight fillers and aggregates include furnace slag, volcanic tuff, pumice, expanded form of clay, shale and perlite, hollow ceramic spheres, hollow plastic sphere of expanded plastic granules and such. For production of cement panels fillers of expanded clay and shale particularly useful. Expanded plastic granules and hollow plastic sphere, when used in a composition that are needed in very small quantities based on weight because of their extremely low bulk density.

[00104] depending on the choice lightweight filler or placeholder, the weight ratio lightweight filler or aggregate to the reacting mixture of powder to be approximately 1/100-200/100, preferably approximately 2/100-125/100. For example, for the manufacture of lightweight cement panels weight ratio lightweight filler or aggregate to the reacting mixture of powder preferably will be approximately 2/100-125/100. In applications where the property lightweight product is not a critical feature, river sand and coarse-grained filler commonly used in concrete construction, can be applied as part of the compositions of the present invention.

Initial temperature of the suspension

[00105] In this invention formation of suspensions under conditions which ensure high initial temperature of the suspension, as revealed, is important to achieve quick setting and hardening cement compositions. Initial temperature of the suspension should be from at least approximately room temperature to approximately 35 C. the Temperature of the suspension in the range of 38 C to 41 degrees C give a short setting time. Initial temperature of the suspension preferably approximately 38o -41 C.

[00106] In General, in this range increase the initial temperature of the suspension increases the rate of temperature rise, when the reactions take place, and reduces the time setting. Thus, the initial temperature of the suspension 95 degrees Fahrenheit (35 degrees C) is more preferable than the initial the temperature of the suspension 90 degrees Fahrenheit (32,2°C), a temperature of 100 degrees F (37,7°C) is more preferable than 95 degrees Fahrenheit (35 degrees), the temperature of 115 degrees Fahrenheit (41,1°C) is more preferable than 100 degrees F (37,7 C), a temperature of 110 degrees Fahrenheit (40,6°C) is more preferable than 105 degrees Fahrenheit (41,1 degrees C) and so on I believe that the effects of increasing the initial temperature of the suspension reduced because achieved an upper limit wide temperature range.

[00107] As will be clear specialist in this area, the achievement of the initial temperature of the suspension, you can perform more than one way. Probably the most convenient way is the heating of one or more of the components of the suspension. In the examples given invention of supplied water is heated to the temperature, such that when added to dry reacting powders and arealesouj solids formed suspension has the desired temperature. Alternatively, if you want, solids can be provided with temperatures above ambient. The steam is used to provide heating suspension is another possible way that can be adopted.

[00108] Although potentially slower suspension can be obtained at ambient temperature and at once (for example, for approximately 10, 5, 2, or 1 minute) is heated to a temperature increase to about 90 degrees F or higher (or any of the other above-mentioned bands), and the effects of this invention is still achieved.

The production of prefabricated concrete products such as cement panels

[00109] Precast concrete products such as cement panels, produced most efficiently in a continuous process in which the mixture is reacting powder mix with fillers, additives and other ingredients, then add water and other chemical additives directly before placing the mixture in the form or continuous casting and forming the tape.

[00110] due to the characteristics of fast setting cementitious compounds should be assessed that the mixing of dry components cement mixture with water is usually will run immediately before surgery otlivanija. As a consequence of formation of alkali-silica-hydrate, and/or other hydrates of aluminium silicates, and/or aluminosilicate calcium compounds, concrete product becomes hard, ready to rip, processed and placed on top of each other for additional curing.

EXAMPLES

[00111] The following examples illustrate the influence of additives of potassium citrate and sodium citrate on the behavior of a suspension with increasing temperature, characteristics of setting and compressive strength of the cube (CCS) cementitious compositions of the present invention, including the mixture of Portland cement, class C fly ash and calcium the sulfate dihydrate (natural gypsum) as components of reacting powder.

[00112] Admixtures used to activate fly ash, such as potassium citrate, sodium citrate and optional supplements such as citric acid, borax, boric acid, were added to the water before mixing mixed with ash dust, cement and any optional lightweight filler.

[00113] Compositions described in this document were combined using the weight ratio of filler made of expanded clay for cement (reacting powder) 0,56:1,0.

[00114] Temperature liquids adjusted before mixing with cement to obtain a certain temperature of the mixture. After mixing in Hobart mixer approximately 280 grams mixture was placed in 6 oz can STYROFOAM Cup and placed in isolation in a STYROFOAM. Temperature response was measured continuously using the computerized data collection provided by Fluke Corporation, Everett, WA 98203, as part of its product HYDRA SERIES Portable Datae Acquisition.

[00115] Final setting time identified with needles Gilmore according to the procedure prescribed in ASTM C. Cubes kept inside a sealed plastic bag containing a wet towel at a temperature of 68°to 3-hour test, and the dice for a 14-day test otvetili within 24 hours at 68°C, and then removed from the incubator and advanced otvetili at room temperature. In some cases the mixture example poured with water of room temperature and cubes kept at room temperature until the time of the test. Maximum load required for crushing cubes, measured using a compression device SATEC UTC 120HVL programmed to match the degree of load determined in the procedure according to ASTM C.

[00118] Temperature liquids handled before mixing with cement to obtain a certain temperature of the mixture. After mixing in Hobart mixer mix (approximately 280 grams) were placed in a 6 oz can STYROFOAM Cup and placed in isolation in a STYROFOAM. Temperature response was measured continuously using a computer program for data collection. The maximum degree of temperature increase and maximum temperature and time to the maximum temperature was used as evidence reactivity experimental mixtures.

[00119] Initial and final setting time identified with needles Gilmore according to ASTM C. The aim was to reach the final setting in less than 10 minutes, preferably 5-7 minutes after mixing. To test the compressive strength of cubes (2 inches x 2 inches x 2 inches) (5.1 cm x 5.1 cm x 5.1 cm) was kept inside a sealed plastic bag containing a wet towel at a temperature of 68 degrees C (154 F) until the time of the test. Compressive strength 3 blocks from each of the mixture defined in 5 hours after adding mixed fluids. Maximum load required for crushing cubes, measured using a compression device SATEC UTC 120HVL programmed to respond to the degree of load, a procedure ASTM C.

[00120] Raw materials and ingredients used in these examples were the following:

[00121] Type III Portland cement

[00122] Plaster (for example, natural gypsum)

[00123] Class C fly ash

[00124] the Filler made of expanded clay

[00125] Boric acid

[00126] Borax

[00127] Citric acid

[00128] Sodium citrate (trisodium citrate monohydrate) [00129] Potassium citrate (tripotassium citrate monohydrate) [00130] Potassium hydroxide

[00131] In the examples below the dry ingredients reacting powder and some used filler mixed with water under conditions who provided the initial suspension temperature above the ambient. Typically used hot water with a temperature that gave suspension with initial temperature in the range of 90°-115 F (32-41 C).

[00132] Weight ratio of water to reacting powder is typically in the range of 0,2-0,30:1.0 preferred lower weight ratio of 0.2-0,23:1 when reacting powder consists mainly of 100% wt. fly ash, and the number of Portland cement and gypsum minimized according to the preferred implementation of this invention.

[00133] Examples report the setting of the composition, characterized by start and end time of setting, as measured using the aforementioned needles Gilmore defined in the test procedure ASTM C, and high initial compressive strength ASTM C.

[00134] Example 1 (mix 1-8)

[00135] table 1 shows the composition of mixtures containing Portland cement Type III and Class C fly ash in the weight ratio of 20/100 and different dosage of sodium citrate with boric acid, brown or citric acid. In these compositions the level of potassium hydroxide were kept constant at 1,8% by weight of fly ash and Portland cement. In Table 1 the data show that the increase of sodium citrate reduces the final setting time and increases the early compressive strength. Comparison of mixtures of 1, 3, and 4 with a dosage of sodium citrate 5,4, 10,8 and 16.2 grams, respectively, shows that the final setting time reduced to 11, 8.1 and 5.5 minutes, respectively. When comparing the strengths of compression (C.S.) 3 hours (early compressive strength) and in 14 days mixture of 2, 5 and 7 containing identical number of boric acid, but with levels of sodium citrate 10,8, 16.2 and 21.8 grams, respectively, showed increased compressive strength, measured after 3 hours and 14 days, with increased sodium citrate.

[00136] the Data in TABLE 1 also show that the effect of sodium citrate reduced in the presence of the Boers in comparison with the effect of mixtures containing boric acid. Compared mix 6 and 7 contain the same level (21.8 g) sodium citrate, but in the case of mixtures 6 is used (7.2 g) citric acid, as in the case of a mixture 7 used (7.2 g) boric acid, mixture, contains citric acid, has a slightly better 3-hour compressive strength, but this 14-day compressive strength.

Sodium citrate

Boric acid

Citric acid

Setting time

3-hour C.S.

A 14-day C.S.

g means grams. C.S. means compressive strength. In TABLE 1 all composition of the mixture contain 900 g Class C fly ash, 180 grams of Type III Portland cement, 250 g of water and 608 g lightweight filler made of expanded clay.

[00138] the Effect of increasing sodium citrate to increase the temperature of the mixture to mix with brown, boric acid and citric acid is shown plotted the graphs in figure 1 and figure 2. As you can see in figure 1 mixture with higher doses of sodium citrate have more sharp temperature rise within the first 5-10 minutes. In figure 2 it is noted that mixtures containing citric acid, achieved a significantly higher temperature increase (approximately 230-230 F) during the first 45-90 minutes after mixing. The rate of temperature rise, as it is known in the field, connected with the speed of response and the setting time of the mixture. When rendering results for mixtures 6 and 8, containing 16,2 and 21.6 grams of sodium citrate and 7.2 grams of citric acid, figures 1 and 2, it is shown that these compounds have two separate point decline in approximately 2-3 minutes to 1 and approximately 15-30 minutes in figure 2.

[00139] In the case of mixtures 5 and 7, containing the same amount of sodium citrate and boric acid instead of citric acid, the second point of the declination system in figure 2 are not as defined as in mixtures 6 and 8. The first peak of the response, as recognized in the field, connected with final compressive strength of the mixture, while the second peak, as it is known, is connected with the early strength of the compression mixture. Such a comparison shows that the presence of citric acid facilitates the second reaction, which correlates with relatively higher early strengths compressive measured for mixtures containing citric acid, compared with mixtures containing boric acid.

[00140] Example 2

[00141] has Prepared another set of mixes, marked 1-5. TABLE 2 shows these compositions containing 900 grams of Type III Portland cement, 180 grams of class C fly ash, 250 grams of water and 608 g lightweight filler of expanded clay.

[00142] TABLE 2 shows the composition, containing Portland cement type III and class C fly ash in the weight ratio of 20/100, containing different levels of potassium hydroxide and constant dosage of sodium citrate (16.2 g)maintained constant at 0.67% wt. and 1.5% (by weight fly ash and Portland reacting powder), and citric acid (7.2 g).

[00143] the Results in TABLE 2 show that with the increase in potassium hydroxide setting time reduced and early strength and compression strength, measured in 14 days, increase. Mix 5 from 19.7 g (1.8%wt.) potassium hydroxide has compressive strength after 14 days 8604 psi and time setting, reduced to 4.0 per minute. 3-hour durability on compression mixture for 3 with 1% potassium hydroxide 5072 psi was about two times more compressive strength 2482 psi for a mixture of 1, which contained 0,32% wt. potassium hydroxide.

Composition (1) , the temperature increase which is shown in figure 2

Sodium citrate

Limon th acid

Class C fly ash

Type III Portland cement

Setting time

Compressive strength Psi

to 116.2

(1) added 250 grams of water and 608 g lightweight filler made of expanded clay. The weight ratio of water to reacting powder supported when 0,23/1,0.

[00145] the Effect of increasing the amount of potassium hydroxide to increase the temperature of the mixture for mixtures TABLE 2 shows the graphs in FIG. 3 and 4. As shown in FIG. 3, the rate of temperature rise for mixtures 1 and 2, containing 3.5 g (0,32%) and 5.6 g (0,52%) potassium hydroxide, respectively, was gentle compared to the relatively more sharp rate of temperature rise within the first 5 minutes for mixtures 3, 4 and 5, containing 11,2 g (1.0%), 15.5 g (1,4%) and 19.7 g (1,8%) potassium hydroxide. The speed increase temperature correlates with the speed of response and the setting time.

[00146] Graph in FIG. 4 shows that the increase of potassium hydroxide significantly increased temperature increase of approximately 205°-210 degrees F for 1 hour after mixing.

[00147] Example 3 (mix 1-9)

[00148] TABLE 3 details shows the composition with different weight ratios of Portland cement type III and class C fly ash and various ratio of water to reactive solids. Weight of potassium citrate, sodium citrate and citric acid kept constant at 1,8%, 1,5% and 0.67%, respectively, relative to the weight of the fly ash and Portland cement. In each mixture added 600 grams lightweight filler made of expanded clay. As shown in TABLE 3, the increase in the content of fly ash and reduction of water content reduced the time of setting up approximately 6 minutes and increased 3-hour compressive strength up to nearly 6,000 psi. Also observed that the effect of the decline in the ratio of water to cement has a more pronounced effect on the compressive strength of mixtures containing fly ash and not containing Portland cement.

[00151] did another set of mixes of cement compositions with a lightweight filler marked Mixture 1-5. The composition is shown in TABLE 4, contain different doses of potassium or sodium citrate citrate for mixtures containing two different weight ratio ash dust and Portland cement.

[00152] As shown in TABLE 4, mixtures, such as 4 and 5, which only contain potassium citrate and do not contain potassium hydroxide or citric acid, have reached final setting time is in the range of about 5 minutes and had a 3-hour compressive strength 6000-7800 psi, over 60% strength over 10000 psi reached 14 days. When comparing mixtures 4 and 3 noted that the mixture 4 with 100% wt. fly ash and without Portland cement had a higher compression strength 7823 psi compared to 5987 psi for a mixture of 3, which contained 86.4% of fly ash and 11.6% of Portland cement. Both mixtures 3 and 4 had potassium citrate 4,0% wt. the total weight of a fly ash and Portland reacting powder.

[00153] In the case of mixtures of 3 and 5 of the temperature of the water mixture is reduced to 35 degrees Celsius compared to 75 C for preventing an instant shvatyvanija. Cubes, tested in 14 days, stood at 65 C for a period of 24 hours, and then kept at room temperature until the time of the test. The weight ratio of water to reacting powder supported at 0.2/1.0 for all of the mixes.

[00154] the Use of Portland cement under these test conditions gave solutions with lower compression strength, when the dosage potassium citrate increased. For example, a mixture of 3 with 4.0% wt. potassium citrate had compressive strength 5987 psi compared to 6927 psi measured for a mixture of 5, which contained only 2.5 wt.% potassium citrate. There is an additional compression strength, increased after 3 hours of strength and 14-day strength to more than 10,000, psi.

[00155] the Data in TABLE 4 show that the final setting time of 4.8-5.1 per minute can be achieved with strengths in compression in the range of more than 5,900 to more than 7800 psi, can be obtained according to the invention, without the use of potassium hydroxide.

All songs contain 600 g lightweight filler made of expanded clay and 216 g water

Sodium citrate

Potassium citrate

Class C fly ash

Type III Portland cement

Setting time (min)

Density pcf

Compressive strength Psi

Weight, g

A 14-day

[00157] Graph on FIGURE 4 shows that the mixture of potassium or sodium citrate citrate reached relatively high temperatures during the first few minutes, like the mixtures that contain potassium hydroxide and citric acid in the previous examples.

[00158] Example 5 (mixture 1-7)

[00159] Made a different number of mixtures 1-7 lightweight cement compositions. Mix in this example contain sodium or potassium citrate without potassium hydroxide. Used in the mix the water in the number 216 g had a room temperature 24C compared to 75C water used in most of the previous examples. The results, shown in TABLE 5, show that the mixture can achieve relatively high strength on compression without the need of hot water. The mixture contain 1-5 weight ratios of fly ash and Portland cement 88,4:11,6, whereas mix 6 and 7 have the weight ratios of fly ash to Portland 63,4:36,6 and 75.6:24,1, respectively.

[00160] As shown in TABLE 5, the mixture 1-2 with potassium citrate or mixture with 3-5 sodium citrate reached the final setting time for 5-8 minutes and on-time strength at compression in the range of 5,268 to over 5757 psi. It should be noted, for mixtures 3-5 that contain 11,6% wt. Portland cement, there is no effect from the increase in potassium citrate above 2.4 wt.%. The weight ratio of water to all reacting powder was 0.2/1,0.

[00161] Final setting time for mixtures 6 and 7, containing fly ash and plaster, increased to 16 to 20 minutes and 3 hours compressive strength significantly decreased with the increased quantities of gypsum to 3352 psi and 4271 psi, respectively. It assumes the worst interaction between gypsum, fly ash and dust and potassium citrate. Less data 14-day strength compression is also reduced with increased amounts of gypsum.

Composition*used in Example 5

Sodium citrate

Potassium citrate

Class C fly ash

Type III Portland cement

Time Tong Yvani I

Compressive strength psi

Weight, grams

A 14-day

of 5,268

115, 8mm

* added 600 g lightweight filler expanded clay

[00165] This example summarizes the effect of adding Portland cement and/or silica thin dust on the compressive strength of compositions on the basis of fly ash/potassium citrate. The weight ratio of water to all reacting powder supported when 0,23/1,0. TABLE 6 shows the final setting time, density, compressive strength for these mixtures. TABLE 6 shows that the density of such mixtures are in the range of 112-117 pcf. The data in TABLE 6 show that a mixture 4, containing 100% of fly ash and zero percent Portland cement or silica thin dust, had a 3-hour compressive strength, which was 20% higher in comparison with mixes 1-3, which contained approximately 83% of fly ash and approximately 17% of the mixture of Portland cement and fine silica dust. Data 14-day compressive strength shown are approximately 30-40% higher durability on compression mixture for 4 with a 100% fly ash.

The compositions described in Example 6 with 600 grams of lightweight filler of expanded clay and 250 grams of water

It citrate

Class C fly ash

Portland cement

Fine silica dust

Final gripe

3-hour CCS

A 14-day CCS

the weight. grams

of 116.7

[00167] Example 7

[00168] Five mixtures, shown in TABLE 7, obtained for testing the pH. Mix 1-3 did not contain fine silica dust or gypsum and had a higher 3-hour and 14-day compressive strength than mixture 4, which included Portland cement and plaster, as well as a mixture of 5, which contained a fine silica dust. pH mixtures 1-3 amounted to approximately 12.7-12,8. Mix 4, which contain fly ash and gypsum in the weight ratio 63,4-36,6, had a pH approximately 11 and mix 5 with weight ratio ash dust to fine silica dust 94,4-5,6 also had a relatively low pH of 11.5. The weight ratio of water to all reacting powder supported when 0,20/1,0.

[00169] Thus, in compositions, in which the pH is paying more attention than compression strength, such as concrete, fiber-glass reinforced, blend fly ash with plaster or of fine silica dust can be used to provide products with a lower pH.

Compositions containing 600 grams (g) lightweight filler of expanded clay and 216 g water

It citrate

Na citrate

Class C fly ash

Portland cement

Thin Crempse of MNA dust

Setting time

Compressive strength psi

3-hours Aya

A 14-day

to 11.52

[00171] Primer

[00172] formulations used in the example in TABLE 8. For these mixtures, the proportion of the ash dust to Portland varied dosage potassium citrate 3,5% (by weight fly ash plus Portland cement), and the ratio of water to cementing materials (water: fly ash+Portland cement) was 0.26 for mixtures 1-4 and 0.30 for mixtures 5-8. The results of the strengths compressive clearly show that a higher number of fly ash increased 3-hour compressive strength.

[00173] in Addition, the curves of temperature increase, measured for mixtures 4-7, shown in FIG.6. FIG.6 shows that the temperature was within the first 15 minutes of a higher, since the content of fly ash increased, and the number of Portland cement has decreased in the same proportion of water to reacting powder. Data measured constantly and put it on the schedule at 1-minute intervals for clarity in the presentation of data points.

The compositions described in Example 8 with the addition of each mixture 600 g lightweight filler expanded clay

W/(FA+PC)

Potassium citrate

Class C fly ash

Portland cement

Setting time

Compressive strength Psi

A 14-day

[00175] Example 9

[00176] formulations used in this the example in TABLE 9. This includes two sets of results. For the first four mixes added only fly ash without any of Portland cement, and the ratio of water to ash dust ranged from 0.26 0.17 dosing of potassium citrate, supported by constant at 4% (by weight fly ash). The results of the strengths compressive show that the decrease of water significantly increased 3-hour compressive strength.

[00177] the Second set of results includes a mixture 5-7, which contain a mixture of fly ash and Portland cement. For mixtures 5-7 compressive strength is reduced when the amount of fly ash were lowered, and the number of Portland cement increased. In addition, the final setting time for mixtures with Portland cement fell below the 5 minutes that shows the instantaneous setting.

[00178] FIG.7 shows the temperature increase for mixtures 1-4 in this example. FIG.7 shows that for mixtures containing fly ash without Portland cement, reducing the water content increases the maximum temperature.

[00179] PIG shows the temperature increase for mixtures 3, 5, 6 and 7. FIG shows that the increase of Portland cement adds a second point of inducement to temperature response, which further increases the rate of temperature rise is approximately 30 minutes after stopping the reaction.

[00180] temperature Increase, which accompanies mixture with a lower water content, correlates with higher strength on compression. In contrast, higher temperatures obtained with the increase of Portland cement, does not give high compressive strength. Therefore, another mechanism was responsible for the development of strength of mixtures containing fly ash and Portland cement, compared with mixtures containing only fly ash.

The composition of the Sample 9, containing 600 g lightweight filler made of expanded clay and 43.2 g potassium citrate

W/(FA+RS)

Class C fly ash

Portland cement

Setting time

Compressive strength psi

A 14-day

115, 8mm

[00182] Example 10

[00183] formulations used in the example in TABLE 10. For these mixtures added only fly ash without any of Portland cement. Dosage potassium citrate varied from 2% to 6% (by weight fly ash), and the ratio of water to ash dust kept constant at 0,20. The results in TABLE 10 show, in General, that the compressive strength of mixtures of fly ash increased when the dose was increased potassium citrate. The increase of 3-hour strength is set at a constant level at 5 wt.%, with a mixture of 5 wt.% potassium, reaching comparable 3-hour strength with a mixture with 6 wt.% potassium citrate. A 14-day compressive strength appears to peak at approximately 3,0-4,0 wt.%.

TABLE 10

Composition Example 10, containing 600 g lightweight filler of expanded clay and not containing Portland cement

Class C fly ash

Compressive strength Psi

Setting time

Potassium citrate

the weight. %

A 14-day

121, 1million

[00185] FIG. 9 shows the temperature increase for mixtures with different doses of potassium citrate using only fly ash without Portland cement. These data show that adding potassium citrate improves the speed of rise of temperature of the mixture on the basis of fly ash. However, achieved the maximum temperature is relatively lower than that of mixtures containing Portland cement, discussed in the previous examples.

[00186] Although describes the preferred options for implementation the implementation of this invention, the specialist in this sphere, to which addressed this description, it will be clear that the modification and additions can be made without derogating from the ideas and scope of the invention.

1. The method of obtaining lightweight cement mixture with improved compression strength and resistance to water, including: mixing water, cementing reacting powder, salt, alkali metal citric acid as an accelerator of setting and lightweight filler, where the weight ratio of water to reacting powder is about 0,17-0,35:1,0 reacting powder includes 75-100% wt. fly ash containing at least 50 % by weight of the ash dust-class and 0-25% wt. hydraulic cement and/or plaster, thus setting cementitious mixture is achieved within 4 to 6 minutes of mixing songs without adding zamedlitel shvatyvanija.

2. The method according to claim 1, where reacting powder includes 88,5-100% of fly ash from the weight of reacting powder, does not include hydraulic cement, and does not include gypsum.

3. The method according to claim 1, where the initial temperature of the mixture is approximately 24 degrees C-41 Degrees C.

4. The method according to claim 1, where reacting powder includes 10-40% wt. lime.

5. The method according to claim 1, where salt alkali metal citric acid is in the amount of approximately 1.5-6 wt.% based on the weight of cementing reacting powder.

6. The method according to claim 1, where cementing reacting powder additionally includes fine silica dust.

7. The method according to claim 1, where cementing reacting powder and water are present in the weight ratio of about 0,20-0,23:1 part by weight water to reacting powder.

8. The composition for obtaining a lightweight cement panel, comprising a mixture: cement reacting powder; salt, alkali metal citric acid as an accelerator of setting for reacting powder; lightweight filler and water, where the ratio of water to solids cementing reacting powder mixture is about 0,17-0,35:1 reacting powder includes 75-100% wt. fly ash containing at least 50% wt. fly ash class and 0-25% wt. hydraulic cement and/or plaster, while the composition characterized by the fact that the setting of the mixture is achieved within 4 to 6 minutes of mixing songs without adding zamedlitel shvatyvanija.

9. The composition of claim 8, where the mixture includes approximately 1.5 to 6.0% wt. based on the weight of cementitious powder at least one of salts of alkaline metal citric acid selected from the group comprising sodium citrate, potassium citrate and their mixtures.

10. The composition of claim 8, where the mixture consists of approximately 1,5-4,0% wt. based on the weight of cementitious powder at least one of salts of alkaline metal citric acid selected from the group comprising sodium citrate, potassium citrate and their mixtures.