Use of polycarboxylate ethers for adjusting the setting time of cementitious materials

Abstract

The present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material, especially composition comprising supplementary cementitious materials, said polycarboxylate comb copolymer comprising at least one monomeric unit of the structure (I), and monomeric units selected from the following structures (IIa) or (IIb). The present invention also relates to the use of such copolymers as grinding aids and / or plasticizers for cementitious binder compositions, especially composition comprising supplementary cementitious materials.

Description

[0001] USE OF POLYCARBOXYLATE ETHERS FOR ADJUSTING THE SETTING TIME OF CEMENTITIOUS MATERIALS

[0002] Technical field

[0003] The present invention relates to the use of comb polymers to adjust the setting time of cementitious materials. The present invention also relates to the use of such copolymers as grinding aids and / or plasticizers for the cementitious material composition.

[0004] Background of the invention

[0005] Copolymers of ethylenically unsaturated carboxylic acid and ethylenically unsaturated alcohol alkoxylates have been known for many years as dispersion aids for aqueous dispersions, especially for aqueous dispersions of cementitious binders. Such copolymers are frequently being called polycarboxylate ethers (PCE). PCE act as superplasticizers and reduce the water needed to achieve a certain level of fluidity of a given uncured cementitious material. A reduction of water in cementitious materials is desirable as it leads to less segregation of solid components in the uncured material and to an increased compressive strength of the cured material.

[0006] PCE of various structures and their use as dispersants for mineral binders are well known, for example from EP2687497B1 (Kao Corporation), WO2010 / 085425 (W. R. Grace and Company), and WO2014 / 139857 (Sika Technology AG).

[0007] It is also common to combine PCE with other functional molecules to influence other properties of cementitious materials such as setting time.

[0008] For example, WO2011 / 069919 (Sika Technology AG) discloses an additive composition consisting of at least one grinding aid selected from the group consisting of glycols, monocarboxylic acids with 1 to 4 carbon atoms, and PCE, and at least one retarder. The use of such additive composition is to delay the setting of a mineral binder composition.

[0009] The copolymers described in the prior art are not in all cases suitable to adjust the setting time of cementitious materials. One reason is that cementitious binder compositions have a large variation in possible components. Different cementitious binders used, different aggregates used, different mix ratios of components, etc. may require different copolymers to adjust the setting time of the cementitious materials. There is thus a constant need for specific structures of PCE copolymers to adjust the setting time of cementitious materials to obtain the intended performance.

[0010] Summary of the invention

[0011] It is an object of the present invention to provide suitable PCE-type copolymers for the adjustment of a setting time of cementitious binder compositions, especially compositions comprising supplementary cementitious materials. It is another object of the present invention to provide the compositions of cementitious binder material having adjusted setting time.

[0012] The objective of the present invention has been solved by the subject matter of claim 1.

[0013] Surprisingly, it was found that copolymers of the present invention have the effect of adjustment of the setting time of cementitious materials. Moreover, these inventive copolymers were found to be useful as grinding aids and / or plasticizers for the cementitious material composition. Especially, the setting time of a cementitious binder composition comprising an inventive copolymer can be adjusted as compared to the same binder composition but comprising a polycarboxylate ether type copolymer that is not according to the invention.

[0014] In particular, it has been found that copolymers derived from methoxy polyethylene glycol with short chain length, for example 10 - 40 ethylene oxide repeating units and of ethoxylated, ethylenically unsaturated alcohols, specifically methallyl alcohol, with long chain length, for example 85 - 95 ethylene oxide repeating units are useful to decrease the setting time of a cementitious materials, especially cementitious materials comprising supplementary cementitious materials.

[0015] Further aspects of the present invention are the subject of the independent claims. Preferred embodiments are the subject of dependent claims. Detailed ways

[0016] In a first aspect the present invention relates to the use of polycarboxylate comb copolymer to adjust the setting time of cementitious material, said polycarboxylate comb copolymer comprising at least one monomeric unit of the following structure (I) where

[0017] R1= H, CH3,

[0018] R2= H, C1-C12 alkyl,

[0019] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , n = 1 - 350, preferably 10 - 120, most preferably 30 - 90, and monomeric units selected from the following structures (Ila) or (lib): where

[0020] Ru= H, CH3,

[0021] Rw= H, CH3,

[0022] Rx, Ryindependently of each other are COOM,

[0023] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having the molar ratios of the monomers (Ila) or (lib) (I) in the range of 1 - 30 : 1 - 5, preferably 5 - 15 : 1 - 3, most preferably 1 .5 - 7 : 1 - 1 .5. In polycarboxylate comb polymers of the present invention, either monomeric units of structure (Ila) or monomeric units of structure (lib) are present. It is not possible that both monomeric units (Ila) and (lib) are present within one comb polymer of the present invention.

[0024] According to embodiments, monomeric units of general structure (I) carry mixtures of ethylene oxide groups, propylene oxide groups, and / or butylene oxide groups, for example a mixture of ethylene oxide and propylene oxide groups or a mixture of ethylene oxide and butylene oxide groups.

[0025] According to embodiments, at least 50 mol% groups (A) in general structure (I) are ethylene groups, preferably 100 mol% groups (A) in general structure (I) are ethylene groups.

[0026] Monomer Ila preferably is selected from acrylic acid and / or methacrylic acid.

[0027] Monomer lib preferably has a ring structure and is selected from maleic anhydride, dimethylmaleic anhydride and / or citraconic anhydride.

[0028] Copolymers without an ester group, that is copolymers with p=0, may show an improved storage stability over time.

[0029] Copolymers of the present invention are obtained by copolymerization of the respective monomers. Copolymerization is a process known to the person skilled in the art. Especially, polymer analogous esterification and radical polymerization of different monomers are preferred. Suitable conditions for a process of polymer analogous esterification are for example described in example 1 of WO 2012 / 076596 (Sika Technology AG), whereas suitable conditions for a radical polymerization are for example described in example 1-1 of EP 1103570 (Nippon Shokubai Chem Ind).

[0030] Copolymers of the present invention can be statistical copolymers or have a blockwise or gradient arrangement of the monomers. Statistical copolymers are preferred.

[0031] The molecular weight Mw of a copolymer of the present invention can be measured by GPC using PEG as a standard and may be in the range of 5000 - 200000 g / mol, preferably 10000 - 150000 g / mol.

[0032] According to embodiments, copolymers of the present invention can be in the form of a dispersion or a solution in a liquid, preferably in water. According to further embodiments, copolymers of the present invention can be in the form of a powder. Powders can be preferred for example, where the copolymers of the present invention are to be mixed with other dry ingredients to form dry concrete or dry mortars. The shelf life of such dry concrete or dry mortar can be improved if the copolymer of the present invention is used therein in powder form.

[0033] Means to produce powders of copolymers of the present invention are not particularly limited and are known to the person skilled in the art per se. Such means include spray drying, oven drying, flaking, etc.

[0034] Setting time refers to the period it takes for a cementitious material to change from a liquid, workable state to a solid state. Typically, the setting time is the time it takes from the addition of mixing water to a dry cementitious material until the mixed, wet cementitious does not show plastic behavior anymore. The setting process involves a chemical reaction known as hydration, where the cement particles react with water to form a solid matrix. This process is crucial for the development of strength and durability in the concrete. There are several methods to measure the concrete setting time, e.g., by means of the manual Vicat apparatus according to the standard GB / T 1346 (2011) “Test methods for water requirement of normal consistency, setting time and soundness of the Portland cement”.

[0035] The term “adjust the setting time” as used herein is intended to refer to the ability to manage the duration it takes for cement to transition from a fluid, workable state to a solid state. The term "adjust" in this context means the ability to influence the setting time in various ways. This adjustment can involve either increasing the setting time, decreasing the setting time or maintaining a consistent setting time. In particular, adjustment means a decrease in setting time versus a control not containing the polycarboxylate comb copolymer.

[0036] Within the scope of the present invention, the composition of cementitious material and the targeted setting time determine the use of a certain polycarboxylate ether comb copolymer structure. The setting time can be set to a specific value, or it can be increased or decreased by a factor of x, where x ranges from 0.01 to 5.

[0037] There are various situations in construction where adjusting the setting time of concrete may be desirable. For instance, in cold weather, the setting time of concrete naturally increases because the hydration process slows down at lower temperatures. Accelerating the setting time using admixtures known as accelerators can help ensure that construction activities can proceed in a timely manner. On the other hand, dams’ construction often involves massive concrete placements, with large volumes of concrete being poured continuously. If the concrete sets too quickly, it may become challenging to manage and place the material effectively. Therefore, extending the setting time allows for the placement of concrete without compromising its workability. In certain situations, a consistent and predictable setting time is crucial for precise scheduling and construction planning. In these cases, the goal is to maintain a stable setting time.

[0038] A cementitious material as used herein refers to materials that comprise at least one cementitious binder.

[0039] A cementitious binder, in the context of the present invention, is a binder, which in the presence of water reacts in a hydration reaction to form solid hydrates or hydrate phases. This can be, for example, a hydraulic binder (e.g. cement or hydraulic lime), a latent hydraulic binder (e.g. slag), a pozzolanic binder (e.g. fly ash) or a nonhydraulic binder (gypsum plaster or white lime).

[0040] A cementitious binder composition within the present context is a composition comprising at least one cementitious binder.

[0041] According to embodiments, the said cementitious binder comprises cement and at least one of gypsum, limestone, slag, fly ash or clay.

[0042] Particular preference is given to a cement having a cement clinker content of > 35 wt. %. In particular, the cement is of the type CEM I, II, III, IV orV (according to the standard EN 197-1). A proportion of the hydraulic binder in the total cementitious binder is advantageously at least 5 wt. %, in particular at least 20 wt. %, preferably at least 35 wt. %, especially at least 65 wt. %. In a further advantageous embodiment, the cementitious binder consists to an extent of at least 95 wt. % of a hydraulic binder, in particular cement clinker.

[0043] In one advantageous embodiment the cement additionally contains up to 40 wt. %, preferably up to 35 wt. %, especially up to 20 wt. %, each based on the total dry weight of the cement, of a calcium sulfate. The calcium sulfate may be present in the form of calcium sulfate-hemihydrate, calcium sulfate-dihydrate and / or anhydrite.

[0044] According to further embodiments the cementitious binder composition comprises other binders in addition to or instead of a hydraulic binder. These are, in particular, latent hydraulic binders and / or pozzolanic binders. Suitable latent hydraulic and / or pozzolanic binders are, for example, slag, fly ash, silica dust, silica fume, rice husk shale, burnt shale, trass, and pumice. In an advantageous embodiment, the cementitious binder contains 5-95 wt. %, in particular 5-65 wt. %, especially 15-35 wt. %, of latent hydraulic and / or pozzolanic binders, relative to the total dry weight of the cementitious binder.

[0045] The cementitious binder composition may also be based on calcium sulfate and / or lime as a binder. Calcium sulfate is meant to encompass any of anhydrite, alpha- and beta-calcium sulfate hemihydrate, and calcium sulfate dihydrate. Lime is meant to encompass any of hydraulic lime, air lime, and natural hydraulic lime.

[0046] Gypsum within the present context can be obtained from different sources, such as e.g. gypsum from natural sources, gypsum from flue gas desulphurization (FGD gypsum), phosphogypsum, pyro gypsum, and / or fluoro gypsum. Limestone within the present context stands for calcium carbonate (CaCOs). In preferred embodiments of the present invention the chemical composition of limestone is as defined in standard EN 197-1 (2011). In the alternative, limestone may also stand for magnesium carbonate, dolomite, and or mixtures of magnesium carbonate, dolomite, and / or calcium carbonate. It is especially preferred that limestone within the present context is a naturally occurring limestone mainly consisting of calcium carbonate (typically calcite and / or aragonite) but typically also containing some magnesium carbonate and / or dolomite. Limestone may also be a naturally occurring marl.

[0047] Limestone, within the present context, in particular is a ground material that is not heat treated. Especially, the limestone is not decarbonated. According to embodiments, the limestone has a Blaine surface of 3’000 - 15’000 cm2 / g. The Blaine surface is measured as described in standard EN 196-6 (2010).

[0048] Fly ash within the present context is a fine powder that is a byproduct of burning pulverized coal. Fly ash is a pozzolan. It comprises aluminous and siliceous material. In particular, in a method of the present invention, the fly ash is according to standard JIS 6201 (2015). However, fly ash according to other standard, such as ASTM C618- 22 or EN 450-1 (2012) is also suitable.

[0049] Slag within the present context especially is iron making slag and / or steelmaking slag.

[0050] Steel making slag within the present context is a by-product from the steelmaking process. Steel making slag is obtained for example in the Thomas process, the Linz- Donawitz process, the Siemens-Martin process or the electric arc furnace when iron is converted to steel. Preferentially, steel making slag of the present invention is a type of slag which has not been additionally treated in the hot state or during the cooling process. More specifically, steel making slag of the present invention preferentially is not treated with any of fluorspar, Na2COs, NaHCOs, NaOH, NaCl2, CaCOs, (NH4)2COS, NH4HCO3 or by a steam treatment.

[0051] A very preferred type of steel making slag within the present context is basic oxygen furnace slag (BOF), also called basic oxygen slag (BOS).

[0052] A very preferred type of iron making slag is GGBS (also called GGBFS). A ground granulated blast furnace slag (GGBS) within the present context is obtained by quenching molten iron slag from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder.

[0053] Clays within the present context are solid materials composed to at least 30 wt. %, preferably to at least 35 wt. %, especially to at least 75 wt. %, each relative to its dry weight, of clay minerals. Such clay minerals preferably belong to the kaolin group (such as kaolinite, dickite, nacrite or halloysite), the smectite group (such as montmorillonite, nontronite or saponite), the vermiculite group, serpentine, palygorskite, sepiolite, chlorite, talc, pyrophyllite, micas (such as biotite muscovite, illite, glauconite, celadonite, and phengite) or mixtures thereof. Clay minerals belonging to the kaolin group, especially kaolinite, and micas, especially muscovite and illite, as well as mixtures thereof are especially preferred.

[0054] Clays within the present context can be any type of clays, for example crude clays and / or calcined clays.

[0055] Crude clays are e.g., clay minerals extracted from a quarry, optionally purified and optionally dried.

[0056] Calcined clays may be for example low-temperature calcined clays and / or high- temperature calcined clays. Low-temperature calcined clays are clays that have been thermally treated at temperatures between 500 - 1200°C. High-temperature calcined clays are clay minerals that have been thermally treated at temperatures above 1200°C and typically between 1300 - 1400°C.

[0057] A cementitious binder composition of the present invention may also comprise further ingredients. Preferably, such further ingredients are selected from at least one of aggregates, fillers, additives, and water. The term aggregate as used in the context of the present invention refers to mineral materials that are non-reactive in the hydration reaction of cementitious binders. Aggregates can be any aggregate typically used for cementitious materials such as concrete, mortars, screeds, renders, grouts, coatings, putties or the like. Typical aggregates are for example rock, crushed stone, gravel, slag, limestone, sand, recycled concrete, perlite or vermiculite.

[0058] Fillers within the present context are mineral additions of low particle size that have no cementitious properties. Typical fillers are finely ground calcium carbonates.

[0059] Additives can be any typically used in the concrete or mortar industry. Typical additives include plasticizers, thickeners, retarders, air-entrainers, de-aerating agents, defoamers, corrosion inhibitors, fibers, synthetic organic polymers, expansion producing additives, pigments, strength enhancers, waterproofing additives, alkali- aggregate reaction inhibitors, chromate reducers, and / or anti-microbial agents. Within the present context, additives are not polycarboxylate comb polymers.

[0060] According to embodiments, the cementitious binder comprises, in each case relative to the total dry weight of the cementitious binder,

[0061] (a) 50 - 95 wt. %, preferably 70 - 90 wt. %, most preferably 85 - 95 wt. % of cement,

[0062] (b) 0 - 5 wt. %, preferably 0 - 5 wt. %, most preferably 0 - 5 wt. % of gypsum,

[0063] (c) 0 - 45 wt. %, preferably 5 - 25 wt. %, most preferably 5 - 15 wt. % of limestone,

[0064] (d) 0 - 15 wt. %, preferably 0 - 13 wt. %, most preferably 0 - 10 wt. % of slag,

[0065] (e) 0 - 15 wt. %, preferably 0 - 13 wt. %, most preferably 0 - 10 wt. % of fly ash.

[0066] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material comprising a cementitious binder composed of 50 - 95 wt. % cement and 0 - 5 wt. % gypsum, most preferably 95 wt. % cement and 5 wt. % gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of structure (I) where

[0067] R1= H, CH3,

[0068] R2= H, C1-C12 alkyl,

[0069] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 1 - 350, preferably 10 - 120, most preferably 30 - 90, and monomeric units selected from the structures (Ila) or (lib): where

[0070] Ru= H, CH3,

[0071] Rw= H, CH3,

[0072] Rx, Ryindependently of each other are COOM,

[0073] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group.

[0074] In a particularly preferred embodiment, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material, said comb copolymer comprising monomeric units of the structures (I) and (Ila) as shown below and the cementitious material comprises a cementitious binder composed of 95 wt. % cement and 5 wt. % gypsum

[0075] R1= H, R2= CH3,

[0076] A = ethylene group, x = 0, p = 1 , and n = 10 - 40, where

[0077] Ru= H,

[0078] Rw= H,

[0079] M = H.

[0080] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0081] R1= H, CH3,

[0082] R2= H, C1-C12 alkyl,

[0083] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0084] Ru= H, CH3,

[0085] Rw= H, CH3,

[0086] Rx, Ryindependently of each other are COOM,

[0087] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 .

[0088] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0089] R1= H, CH3,

[0090] R2= H, C1-C12 alkyl,

[0091] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0092] Ru= H, CH3,

[0093] Rw= H, CH3,

[0094] Rx, Ryindependently of each other are COOM,

[0095] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 .

[0096] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0097] R1= H, CH3,

[0098] R2= H, C1-C12 alkyl,

[0099] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0100] Ru= H, CH3,

[0101] Rw= H, CH3,

[0102] Rx, Ryindependently of each other are COOM,

[0103] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 .

[0104] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0105] R1= H, CH3,

[0106] R2= H, C1-C12 alkyl,

[0107] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0108] Ru= H, CH3,

[0109] Rw= H, CH3,

[0110] Rx, Ryindependently of each other are COOM,

[0111] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 .

[0112] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0113] R1= H, CH3,

[0114] R2= H, C1-C12 alkyl,

[0115] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0116] Ru= H, CH3,

[0117] Rw= H, CH3,

[0118] Rx, Ryindependently of each other are COOM,

[0119] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 .

[0120] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0121] R1= H, CH3,

[0122] R2= H, C1-C12 alkyl,

[0123] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0124] Ru= H, CH3,

[0125] Rw= H, CH3,

[0126] Rx, Ryindependently of each other are COOM,

[0127] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 .

[0128] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0129] R1= H, CH3,

[0130] R2= H, C1-C12 alkyl,

[0131] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0132] Ru= H, CH3,

[0133] Rw= H, CH3,

[0134] Rx, Ryindependently of each other are COOM,

[0135] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 .

[0136] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0137] R1= H, CH3,

[0138] R2= H, C1-C12 alkyl,

[0139] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0140] Ru= H, CH3,

[0141] Rw= H, CH3,

[0142] Rx, Ryindependently of each other are COOM,

[0143] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 .

[0144] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 95 wt.% of Portland cement and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0145] R1= H, CH3,

[0146] R2= H, C1-C12 alkyl,

[0147] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0148] Ru= H, CH3,

[0149] Rw= H, CH3,

[0150] Rx, Ryindependently of each other are COOM,

[0151] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1.

[0152] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0153] R1= H, CH3,

[0154] R2= H, C1-C12 alkyl,

[0155] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0156] Ru= H, CH3,

[0157] Rw= H, CH3,

[0158] Rx, Ryindependently of each other are COOM,

[0159] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 .

[0160] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0161] R1= H, CH3,

[0162] R2= H, C1-C12 alkyl,

[0163] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0164] Ru= H, CH3,

[0165] Rw= H, CH3,

[0166] Rx, Ryindependently of each other are COOM,

[0167] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 .

[0168] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0169] R1= H, CH3,

[0170] R2= H, C1-C12 alkyl,

[0171] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0172] Ru= H, CH3,

[0173] Rw= H, CH3,

[0174] Rx, Ryindependently of each other are COOM,

[0175] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 .

[0176] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0177] R1= H, CH3,

[0178] R2= H, C1-C12 alkyl, A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0179] Ru= H, CH3,

[0180] Rw= H, CH3,

[0181] Rx, Ryindependently of each other are COOM,

[0182] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 .

[0183] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I) R1= H, CH3,

[0184] R2= H, C1-C12 alkyl,

[0185] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0186] Ru= H, CH3,

[0187] Rw= H, CH3,

[0188] Rx, Ryindependently of each other are COOM,

[0189] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 .

[0190] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I) where

[0191] R1= H, CH3,

[0192] R2= H, C1-C12 alkyl,

[0193] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0194] Ru= H, CH3,

[0195] Rw= H, CH3,

[0196] Rx, Ryindependently of each other are COOM,

[0197] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 .

[0198] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0199] R1= H, CH3,

[0200] R2= H, C1-C12 alkyl,

[0201] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0202] Ru= H, CH3,

[0203] Rw= H, CH3,

[0204] Rx, Ryindependently of each other are COOM,

[0205] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 .

[0206] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0207] R1= H, CH3,

[0208] R2= H, C1-C12 alkyl,

[0209] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0210] Ru= H, CH3,

[0211] Rw= H, CH3,

[0212] Rx, Ryindependently of each other are COOM,

[0213] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 .

[0214] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 50 - 79 wt.% of Ordinary Portland cement, and 21 - 50 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0215] R1= H, CH3,

[0216] R2= H, C1-C12 alkyl,

[0217] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0218] Ru= H, CH3,

[0219] Rw= H, CH3,

[0220] Rx, Ryindependently of each other are COOM,

[0221] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1.

[0222] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0223] R1= H, CH3,

[0224] R2= H, C1-C12 alkyl,

[0225] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0226] Ru= H, CH3,

[0227] Rw= H, CH3,

[0228] Rx, Ryindependently of each other are COOM,

[0229] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 .

[0230] According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0231] R1= H, CH3,

[0232] R2= H, C1-C12 alkyl,

[0233] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0234] Ru= H, CH3,

[0235] Rw= H, CH3,

[0236] Rx, Ryindependently of each other are COOM,

[0237] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0238] R1= H, CH3,

[0239] R2= H, C1-C12 alkyl,

[0240] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0241] Ru= H, CH3,

[0242] Rw= H, CH3,

[0243] Rx, Ryindependently of each other are COOM,

[0244] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0245] R1= H, CH3,

[0246] R2= H, C1-C12 alkyl,

[0247] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0248] Ru= H, CH3,

[0249] Rw= H, CH3,

[0250] Rx, Ryindependently of each other are COOM,

[0251] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0252] R1= H, CH3,

[0253] R2= H, C1-C12 alkyl,

[0254] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0255] Ru= H, CH3,

[0256] Rw= H, CH3,

[0257] Rx, Ryindependently of each other are COOM,

[0258] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0259] R1= H, CH3,

[0260] R2= H, C1-C12 alkyl,

[0261] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0262] Ru= H, CH3,

[0263] Rw= H, CH3,

[0264] Rx, Ryindependently of each other are COOM,

[0265] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0266] R1= H, CH3,

[0267] R2= H, C1-C12 alkyl,

[0268] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0269] Ru= H, CH3,

[0270] Rw= H, CH3,

[0271] Rx, Ryindependently of each other are COOM,

[0272] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0273] R1= H, CH3,

[0274] R2= H, C1-C12 alkyl,

[0275] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0276] Ru= H, CH3,

[0277] Rw= H, CH3,

[0278] Rx, Ryindependently of each other are COOM,

[0279] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 80 - 94 wt.% of Ordinary Portland cement, and 6 - 20 wt.% of at least one of slag, silica fume, natural pozzolane, fly ash, oil shale, and limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0280] R1= H, CH3,

[0281] R2= H, C1-C12 alkyl,

[0282] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0283] Ru= H, CH3,

[0284] Rw= H, CH3,

[0285] Rx, Ryindependently of each other are COOM,

[0286] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1. According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0287] R1= H, CH3,

[0288] R2= H, C1-C12 alkyl,

[0289] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0290] Ru= H, CH3,

[0291] Rw= H, CH3,

[0292] Rx, Ryindependently of each other are COOM,

[0293] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0294] R1= H, CH3,

[0295] R2= H, C1-C12 alkyl,

[0296] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0297] Ru= H, CH3,

[0298] Rw= H, CH3,

[0299] Rx, Ryindependently of each other are COOM,

[0300] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0301] R1= H, CH3,

[0302] R2= H, C1-C12 alkyl,

[0303] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0304] Ru= H, CH3,

[0305] Rw= H, CH3,

[0306] Rx, Ryindependently of each other are COOM,

[0307] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0308] R1= H, CH3,

[0309] R2= H, C1-C12 alkyl,

[0310] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0311] Ru= H, CH3,

[0312] Rw= H, CH3,

[0313] Rx, Ryindependently of each other are COOM,

[0314] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0315] R1= H, CH3,

[0316] R2= H, C1-C12 alkyl,

[0317] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0318] Ru= H, CH3,

[0319] Rw= H, CH3,

[0320] Rx, Ryindependently of each other are COOM,

[0321] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0322] R1= H, CH3,

[0323] R2= H, C1-C12 alkyl,

[0324] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0325] Ru= H, CH3,

[0326] Rw= H, CH3,

[0327] Rx, Ryindependently of each other are COOM,

[0328] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0329] R1= H, CH3,

[0330] R2= H, C1-C12 alkyl,

[0331] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0332] Ru= H, CH3,

[0333] Rw= H, CH3,

[0334] Rx, Ryindependently of each other are COOM,

[0335] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0336] R1= H, CH3,

[0337] R2= H, C1-C12 alkyl,

[0338] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0339] Ru= H, CH3,

[0340] Rw= H, CH3,

[0341] Rx, Ryindependently of each other are COOM,

[0342] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder comprising or consisting of 40 - 70 wt.% of Ordinary Portland cement, 10 - 30 wt.% of calcined clay, 5 - 40 wt.% of limestone, and 1 - 10 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0343] R1= H, CH3,

[0344] R2= H, C1-C12 alkyl,

[0345] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0346] Ru= H, CH3,

[0347] Rw= H, CH3,

[0348] Rx, Ryindependently of each other are COOM,

[0349] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1. According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0350] R1= H, CH3,

[0351] R2= H, C1-C12 alkyl,

[0352] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0353] Ru= H, CH3,

[0354] Rw= H, CH3,

[0355] Rx, Ryindependently of each other are COOM,

[0356] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0357] R1= H, CH3,

[0358] R2= H, C1-C12 alkyl,

[0359] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0360] Ru= H, CH3,

[0361] Rw= H, CH3,

[0362] Rx, Ryindependently of each other are COOM,

[0363] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0364] R1= H, CH3,

[0365] R2= H, C1-C12 alkyl,

[0366] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0367] Ru= H, CH3,

[0368] Rw= H, CH3,

[0369] Rx, Ryindependently of each other are COOM,

[0370] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0371] R1= H, CH3,

[0372] R2= H, C1-C12 alkyl,

[0373] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0374] Ru= H, CH3,

[0375] Rw= H, CH3,

[0376] Rx, Ryindependently of each other are COOM,

[0377] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0378] R1= H, CH3,

[0379] R2= H, C1-C12 alkyl,

[0380] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0381] Ru= H, CH3,

[0382] Rw= H, CH3,

[0383] Rx, Ryindependently of each other are COOM,

[0384] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0385] R1= H, CH3,

[0386] R2= H, C1-C12 alkyl,

[0387] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0388] Ru= H, CH3,

[0389] Rw= H, CH3,

[0390] Rx, Ryindependently of each other are COOM,

[0391] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0392] R1= H, CH3,

[0393] R2= H, C1-C12 alkyl,

[0394] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0395] Ru= H, CH3,

[0396] Rw= H, CH3,

[0397] Rx, Ryindependently of each other are COOM,

[0398] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0399] R1= H, CH3,

[0400] R2= H, C1-C12 alkyl,

[0401] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0402] Ru= H, CH3,

[0403] Rw= H, CH3,

[0404] Rx, Ryindependently of each other are COOM,

[0405] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0406] R1= H, CH3,

[0407] R2= H, C1-C12 alkyl,

[0408] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0409] Ru= H, CH3,

[0410] Rw= H, CH3,

[0411] Rx, Ryindependently of each other are COOM,

[0412] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1. According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0413] R1= H, CH3,

[0414] R2= H, C1-C12 alkyl,

[0415] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0416] Ru= H, CH3,

[0417] Rw= H, CH3,

[0418] Rx, Ryindependently of each other are COOM,

[0419] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0420] R1= H, CH3,

[0421] R2= H, C1-C12 alkyl,

[0422] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0423] Ru= H, CH3,

[0424] Rw= H, CH3,

[0425] Rx, Ryindependently of each other are COOM,

[0426] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0427] R1= H, CH3,

[0428] R2= H, C1-C12 alkyl,

[0429] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 10 - 30, and monomeric units selected from the structures (Ila) or (lib): where

[0430] Ru= H, CH3,

[0431] Rw= H, CH3,

[0432] Rx, Ryindependently of each other are COOM,

[0433] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0434] R1= H, CH3,

[0435] R2= H, C1-C12 alkyl,

[0436] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0437] Ru= H, CH3,

[0438] Rw= H, CH3,

[0439] Rx, Ryindependently of each other are COOM,

[0440] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0441] R1= H, CH3,

[0442] R2= H, C1-C12 alkyl,

[0443] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0444] Ru= H, CH3,

[0445] Rw= H, CH3,

[0446] Rx, Ryindependently of each other are COOM,

[0447] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0448] R1= H, CH3,

[0449] R2= H, C1-C12 alkyl,

[0450] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib): where

[0451] Ru= H, CH3,

[0452] Rw= H, CH3,

[0453] Rx, Ryindependently of each other are COOM,

[0454] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0455] R1= H, CH3,

[0456] R2= H, C1-C12 alkyl,

[0457] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0458] Ru= H, CH3,

[0459] Rw= H, CH3,

[0460] Rx, Ryindependently of each other are COOM,

[0461] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 1 .0 - 2.9 : 1 . The According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0462] R1= H, CH3,

[0463] R2= H, C1-C12 alkyl,

[0464] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0465] Ru= H, CH3,

[0466] Rw= H, CH3,

[0467] Rx, Ryindependently of each other are COOM,

[0468] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1 . According to embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)

[0469] R1= H, CH3,

[0470] R2= H, C1-C12 alkyl,

[0471] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 120 - 150, and monomeric units selected from the structures (Ila) or (lib): where

[0472] Ru= H, CH3,

[0473] Rw= H, CH3,

[0474] Rx, Ryindependently of each other are COOM,

[0475] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1. It has been found that the use of such polycarboxylate comb polymer with such cementitious binder results in particularly high decrease in the setting time. A short setting time is beneficial in various applications, such as when laying concrete at low temperatures.

[0476] In another particularly preferred embodiment, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material, said comb copolymer comprising monomeric units of the structures (I) and (lib) as shown below and the cementitious material comprises a cementitious binder composed of 95 wt. % cement and 5 wt. % gypsum

[0477] R1= CH3,

[0478] R2= H,

[0479] A = ethylene group, x = 1 , p = 0, and n = 85-95, where

[0480] Ru= H,

[0481] Rw= H,

[0482] M = H.

[0483] It has been found that the use of such polycarboxylate comb polymer with such cementitious binder results in particularly high decrease in the setting time. A short setting time is beneficial in various applications, such as when laying concrete at low temperatures. According to further embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material comprising a cementitious binder composed of 50 - 95 wt. % cement, 0 - 5 wt. % gypsum, 0 - 45 wt. % limestone, 0 - 15 wt. % slag, most preferably 75 wt. % cement, 5 wt. % gypsum, 5 wt. % limestone and 15wt. % slag, wherein said polycarboxylate comb copolymer comprises monomeric units of structure (I)

[0484] R1= H, CH3,

[0485] R2= H, C1-C12 alkyl,

[0486] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 1 - 350, preferably 10 - 120, most preferably 30 - 90, and monomeric units selected from the structures (Ila) or (lib): where

[0487] Ru= H, CH3,

[0488] Rw= H, CH3,

[0489] Rx, Ryindependently of each other are COOM,

[0490] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group. In a particularly preferred embodiment, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material, said comb copolymer comprising monomeric units of the structures (I) and (Ila) as shown below and the cementitious material comprises a cementitious binder composed of 75 wt. % cement, 5 wt. % gypsum, 5 wt. % limestone and 15wt. % slag

[0491] R1= H,

[0492] R2= CH3,

[0493] A = ethylene group, x = 0, p = 1 , and n = 10 - 40, where

[0494] Ru= H,

[0495] Rw= H,

[0496] M = H.

[0497] It has been found that the use of such polycarboxylate comb polymer with such cementitious binder results in particularly high decrease in the setting time. A short setting time is beneficial in various applications, such as when laying concrete at low temperatures.

[0498] In another particularly preferred embodiment, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material, said comb copolymer comprising monomeric units of the structures (I) and (Ila) as shown below and the cementitious material comprises a cementitious binder composed of 75 wt. % cement, 5 wt. % gypsum, 5 wt. % limestone and 15wt. % slag

[0499] R1= CH3,

[0500] R2= H,

[0501] A = ethylene group, x = 1 , p = 0, and n = 85-95, where

[0502] Ru= H, Rw= H, M = H.

[0503] It has been found that the use of such polycarboxylate comb polymer with such cementitious binder results in particularly high decrease in the setting time. A short setting time is beneficial in various applications, such as when laying concrete at low temperatures.

[0504] According to further embodiments, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material comprising a cementitious binder composed of 50 - 95 wt. % cement, 0 - 5 wt. % gypsum, 0 - 45 wt. % limestone, most preferably 50 wt. % cement + 5 wt. % gypsum + 45 wt. % limestone, wherein said polycarboxylate comb copolymer comprises monomeric units of structure (I)

[0505] R1= H, CH3,

[0506] R2= H, C1-C12 alkyl,

[0507] A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 1 - 350, preferably 10 - 120, most preferably 30 - 90, and monomeric units selected from the structures (Ila) or (lib): where

[0508] Ru= H, CH3,

[0509] Rw= H, CH3,

[0510] Rx, Ryindependently of each other are COOM,

[0511] M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group.

[0512] In a particularly preferred embodiment, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material, said comb copolymer comprising monomeric units of the structures (I) and (Ila) as shown below and the cementitious material comprises a cementitious binder composed of 50 wt. % cement + 5 wt. % gypsum + 45 wt. % limestone

[0513] R1= H,

[0514] R2= CH3,

[0515] A = ethylene group, x = 0, p = 1 , and n = 10 - 40, where

[0516] Ru= H,

[0517] Rw= H,

[0518] M = H.

[0519] It has been found that the use of such polycarboxylate comb polymer with such cementitious binder results in particularly high decrease in the setting time. A short setting time is beneficial in various applications, such as when laying concrete at low temperatures.

[0520] In another particularly preferred embodiment, the present invention relates to the use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material, said comb copolymer comprising monomeric units of the structures (I) and (Ila) as shown below and the cementitious material comprises a cementitious binder composed of 50 wt. % cement + 5 wt. % gypsum + 45 wt. % limestone R1= CH3,

[0521] R2= H,

[0522] A = ethylene group, x = 1 , p = 0, and n = 85-95, where

[0523] Ru= H,

[0524] Rw= H,

[0525] M = H.

[0526] It has been found that the use of such polycarboxylate comb polymer with such cementitious binder results in particularly high decrease in the setting time. A short setting time is beneficial in various applications, such as when laying concrete at low temperatures.

[0527] Copolymers of the present invention are used in a cementitious binder composition in an amount of 0.01 - 5 wt. %, preferably 0.01 - 0.3 wt. %, relative to the total dry weight of the cementitious binder.

[0528] According to embodiments, polycarboxylate comb copolymer is present in the amount of 0.01 - 5 wt. %, preferably 0.01 - 0.3 wt. %, relative to the total dry weight of the cementitious binder.

[0529] All features and embodiments as described above, also applied to this aspect.

[0530] In another aspect the present invention relates to a method for the dry grinding of a cementitious material, said method comprising the steps of a) providing the cementitious material described above, b) dry grinding the cementitious material, c) providing a polycarboxylate comb polymer described above, and d) adding said comb polymer to said cementitious material before and / or during the dry grinding of the cementitious material.

[0531] Therefore, said polycarboxylate comb polymers can be useful as a grinding aid and / or as means to adjust the setting time of cement.

[0532] According to embodiments, the method comprises adding at least one other cement grinding aid selected from the group consisting of alkylene glycols, amino alcohols, alkanol amines and mixtures thereof.

[0533] Preferably, the grinding aid is selected from 1 ,3-propanediol, a carboxylic acid, a sulphonated amino alcohol, boric acid, a salt of boric acid, a salt of phosphoric acid, sorbitol, a saccharide, a gluconate, iron sulphate, tin sulphate, an antimony salt, an alkali metal salt, an alkaline earth metal salt, lignin sulphonate, glycerol, melamine, melamine sulphonate, monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, ethylene glycol, propylene glycol, polyethylene glycol and mixtures thereof.

[0534] All features and embodiments as described above, also applied to this aspect.

[0535] In another aspect the present invention relates to an admixture composition to adjust the setting time of cementitious material as described above or useful in a method for the dry grinding of a cementitious material described above, said admixture comprising or consisting of: a) 50% - 100% wt. %, especially 90 - 100 wt. %, of polycarboxylate ether comb copolymer; and b) 0 - 50% wt. %, especially 0-10 wt. %, of alkylene glycols; and c) 0 - 50% wt. %, especially 0-10 wt. %, amino alcohols.

[0536] In preferred embodiment, said admixture comprises 30 - 40 wt. % of TEA (triethanolamine), 5 - 10 wt. % of DEG (diethylene glycol) and 55 - 65 wt. % of polycarboxylate ether comb copolymer of the present invention.

[0537] All features and embodiments as described above, also applied to this aspect.

[0538] The following examples will further illustrate the present invention. They are not intended to limit the scope of the invention in any way. Examples

[0539] Preparation of polymer P1

[0540] 330 g of water, 330 g of methallyl polyethylene glycol (OH-terminated, Mw = 4000 g / mol), 42 g of acrylic acid, 102 g of a 16% aqueous solution of NaOH, 1 .5 g of a 10% aqueous solution of Fe(ll)SO4 ■ 7 H2O, and 2 g sodium hypophosphite were added into a reaction vessel with a stirrer.

[0541] Then 10 g of a 30% aqueous hydrogen peroxide solution and 4 g of a 5% aqueous rongalite solution were added dropwise at a temperature of 20 °C - 35 °C over a period of 70 min with stirring.

[0542] 120 minutes after the start of the dropwise addition, a clear viscous polymer solution was obtained.

[0543] Preparation of polymer P2

[0544] 145 g of a 50 w% aqueous solution of partly neutralized polyacrylic acid (Mw = 15 4000 g / mol), and 7.5 g 50 w% sulfuric acid were placed in a glass reactor fitted with a thermometer, stirrer, a gas inlet tube and a distillation assembly. The solution was heated to 70°C and a mixture of 52 g of methoxy-terminated polyethylene glycol with Mw = 1000 g / mol and 300 g of methoxy-terminated polyethylene glycol with Mw = 3000 g / mol was added. The mixture was heated up under a steady stream of nitrogen and kept at 165°C. After stirring at this temperature for 6 h, the mixture was allowed to cool to room temperature. The pH of the resulting mixture was approx. 3.

[0545] As a result, copolymer P2 comprising two polyethers of different chain length, i.e. , different number of repetitive units n, was synthesized. The side chains were a mixture of n=12 (ni) and n=36 (n2).

[0546] Preparation of polymer P3

[0547] 320 g of water, 76.6 g of maleic acid and 330 g of an allyl polyethylene glycol (OH- terminated, Mw = 1200 g / mol) were placed in a reaction vessel with a stirrer.

[0548] Then 19 g of ammonium persulfate dissolved in 100 g of water was added at a temperature of 75°C to 80°C and a pH of 2 - 4 for 4 hours with stirring.

[0549] A clear viscous polymer solution was obtained 240 min after the start of dripping, which was then partially neutralized with 50% sodium hydroxide solution. Preparation of polymer P4

[0550] 394 g of water, 394 g of isoprenyl polyethylene glycol (OH-terminated, Mw = 2400 g / mol), 42 g of acrylic acid, 121.8 g of a 16% aqueous solution of NaOH, 1.8 g of a 10% aqueous solution of Fe(ll)SO4 ■ 7 H2O, and 2.4 g sodium hypophosphite were added into a reaction vessel with a stirrer.

[0551] Then 11 .9 g of a 30% aqueous hydrogen peroxide solution and 4.8 g of a 5% aqueous rongalite solution were added dropwise at a temperature of 20°C - 35°C over a period of 70 min with stirring.

[0552] 120 minutes after the start of the dropwise addition, a clear viscous polymer solution was obtained.

[0553] The following table 1 offers an overview of the obtained copolymers P1 - P4.

[0554] Table 1: copolymers P1 - P4

[0555] * corresponds to the molar ratio of monomeric units of structures (Ila) or (lib) to monomeric units of the structure (I) n.d.: not defined

[0556] Cement setting time test methodology

[0557] Cement setting time was measured according to the standard GB / T 1346 (2011 ) “Test methods for water requirement of normal consistency, setting time and soundness of the Portland cement”.

[0558] Cement samples were prepared by mixing of the cementitious binder as shown in the below table 2 with the respective polymer and water. The used cement was a Portland cement clinker in accordance with GB T 21372 (2008). Other types of cement can be also used in the respective compositions. The amount of the respective polymer (table 2) was 0.08%, in each case relative to the weight of cementitious binder.

[0559] For the reference specimens, 0.015% of TEA (triethanolamine, Sigma-Aldrich) relative to the weight of cementitious binder was added instead of the polymer. The setting time (table 2) is expressed as a decrease [in %] in comparison to the reference specimen. Table 2:

[0560] * A positive value indicates a decrease in setting time, a negative value indicates an increase in setting time. It can be seen from the results in table 2, that it is possible to adjust the setting of a given cementitious material by careful choice of the polycarboxylate ether comb copolymer. Using various types of the copolymers of the present invention yields distinct effects on the setting time of the cementitious material. Additionally, using the same copolymer structure with different compositions of cementitious binders results in varying effects on the setting time. For example, the use of polymer P4 with three different cementitious binder compositions (samples S6, S7, and S8 in table 2) resulted in an extension of the setting time for sample S6 and a reduction in the setting time for samples S7 and S8 to varying extents.

Claims

Claims1 . Use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material, said polycarboxylate comb copolymer comprising at least one monomeric unit of the structure (I)whereR1= H, CH3,R2= H, C1-C12 alkyl,A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , n = 1 - 350, preferably 10 - 120, most preferably 30 - 90, and monomeric units selected from the structures (Ila) or (lib):whereRu= H, CH3,Rw= H, CH3,Rx, Ryindependently of each other are COOM,M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having the molar ratios of the monomers (Ila) or (lib) : (I) in the range of 1 -30 : 1 - 5, preferably 5 - 15 : 1 - 3, most preferably 1 .5 - 7 : 1 - 1 .5.

2. The use according to claim 1 , wherein at least 50 mol%, more preferably 80 mol%, especially 100 mol%, of groups (A) in general structure (I) are ethylene groups.

3. The use according to any of the preceding claims wherein said cementitious material comprises a cementitious binder selected from cement and at least one of gypsum, limestone, slag, fly ash or clay.

4. The use according to claim 3 wherein said cementitious binder comprises, in each case relative to the total dry weight of the cementitious binder,(a) 50 - 95 wt. %, preferably 70 - 90 wt. %, most preferably 85 - 95 wt. % of cement,(b) 0 - 5 wt. %, preferably 0 - 5 wt. %, most preferably 0 - 5 wt. % of gypsum,(c) 0 - 45 wt. %, preferably 5 - 25 wt. %, most preferably 5 - 15 wt. % of limestone,(d) 0 - 15 wt. %, preferably 0 - 13 wt. %, most preferably 0 - 10 wt. % of slag,(e) 0 - 15 wt. %, preferably 0 - 13 wt. %, most preferably 0 - 10 wt. % of fly ash.

5. The use according to any of the preceding claims, wherein the polycarboxylate comb copolymer is present in the amount of 0.01 - 5 wt. %, preferably 0.01 - 2 wt. %, most preferably 0.01 - 0.3 wt. %, relative to the total dry weight of the cementitious binder.

6. The use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of95 wt. % of Portland cement and 5 wt. % of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)R1= H, CH3,R2= H, C1-C12 alkyl,A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n =50 - 100 , and monomeric units selected from the structures (Ila) or (lib):whereRu= H, CH3,Rw= H, CH3,Rx, Ryindependently of each other are COOM,M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 5.1 - 7.5 : 1.

7. The use according to claim 6, characterized in that a) R1= H, R2= CH3, x = 0, p = 1 , n = 10 - 40, A = ethylene group, Ru= H, Rw= H and M = H or b) R1= CH3, R2= H, x = 1 , p = 0, n = 85 - 95, A = ethylene group, Ru= H, Rw= H and M = H8. The use of a polycarboxylate comb copolymer to adjust the setting time of a cementitious material comprising a cementitious binder consisting of 75 wt.% of Ordinary Portland cement, 15 wt.% of slag, 5 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)R1= H, CH3,R2= H, C1-C12 alkyl,A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib):whereRu= H, CH3,Rw= H, CH3,Rx, Ryindependently of each other are COOM,M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1.

9. The use according to claim 8, characterized in that a) R1= H, R2= CH3, x = 0, p = 1 , n = 10 - 40, A = ethylene group, Ru= H, Rw= H and M = Hor b) R1= CH3, R2= H, x = 1 , p = 0, n = 85 - 95, A = ethylene group, Ru= H, Rw= H and M = H10. The use of a polycarboxylate comb copolymer to decrease the setting time of a cementitious material comprising a cementitious binder consisting of 50 wt.% of Ordinary Portland cement, 45 wt.% of limestone, and 5 wt.% of gypsum, wherein said polycarboxylate comb copolymer comprises monomeric units of the structure (I)R1= H, CH3,R2= H, C1-C12 alkyl,A independently of each other is an alkylene group with 2 - 8 C atoms, x = 0, 1 or 2, p = 0, 1 , and n = 50 - 100, and monomeric units selected from the structures (Ila) or (lib):whereRu= H, CH3,Rw= H, CH3,Rx, Ryindependently of each other are COOM,M is selected from H, alkali metal, alkali earth metal, ammonium or organic ammonium group, and having a molar ratio of the monomers (Ila) or (lib) : (I) in the range of 3.0 - 5.0 : 1.

11. The use according to claim 10, characterized in that a) R1= H, R2= CH3, x = 0, p = 1 , n = 10 - 40, A = ethylene group, Ru= H, Rw= H and M = H or b) R1= CH3, R2= H, x = 1 , p = 0, n = 85 - 95, A = ethylene group, Ru= H, Rw= H and M = H12. A method for the dry grinding of a cementitious material as claimed in claim 3 or4 said method having the steps of a) providing the cementitious material as claimed in claim 3 or 4, b) dry grinding the cementitious material, c) providing a polycarboxylate comb polymer as claimed in claim 6 - 11 , and d) adding said polycarboxylate comb polymer to said cementitious material before and / or during the dry grinding of the cementitious material.

13. The method according to claim 12 further comprising adding at least one other cement grinding aid selected from the group consisting of alkylene glycols, amino alcohols, alkanol amines and mixtures thereof.

14. An admixture composition to adjust the setting time of cementitious material according to claim 3 or 4 or useful in a method according to claims 12 and 13, said admixture composition comprising: a) 50% - 100% wt. %, in particular 70 - 100 wt. %, especially 90 - 100 wt. %, of polycarboxylate ether comb copolymer; and b) 0 - 50% wt. %, in particular 0 - 30 wt. %, especially 0-10 wt. %, of alkylene glycols; and c) 0 - 50% wt. %, in particular 0 - 30 wt. %, especially 0-10 wt. %, amino alcohols.

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