Additive for the prevention of the loss at fluidity of cement mixtures.
The invention concerns an additive for cement mixtures, their loss at fluidity prevents soli.
The expression “cement mixtures” soli all types of products cover, which are manufactured by mixing water with cement, if necessary aggregate and other additives. Examples are cement paste, Grout, mortar and Beton.
In such cement mixtures frequently water reducing means (normally one with air voids screen end characteristic) will become begun and in particular supercondensors constantly benutzt.
A disadvantage of these additives is however that with the time a loss at fluidity is to be determined, which are called in the technical language “slump Ioss”. “Slump” is translated in the following as setting measure and refers to the well-known method for the measurement of the fluidity of Zementmischungen.
With most building projects the concrete nowadays as so-called “readymixed concrete”, i.e. as finished concrete delivered. In order to prevent the mentioned loss at fluidity, the supercondensor on the building site is added shortly before pouring. This method causes however an additional mechanism and personnel, which makes and raises the price of the processing complicated. Additives were already suggested, in order to solve this problem, however all this connected with certain disadvantages sind.
It was now found that by additive of certain polymers and their mixtures with certain salts the problem of the loss at fluidity can be repaired. The invention concerns thus a polymere additive for cement mixtures, which contains at least a polymere connection or a salt of it, which is a copolymer from a) one shark-best of the maleic acid and a connection of the formula I RO (AO) mH (l) where R a C1-2o-Alkylgruppe, A a C2. - 4-AIkylengruppe and m a number from 2 to 16 mean, and b) a monomer of the formula IL CH2=CH-CH2 (OA) nOR (11) where R a C1-2o-AIkylgruppe, A a C2--4-Alkylengruppe and n a number from 1 to 90 bedeuten.
Bevo ugten polymers have an average molecular weight of 5000 to 500,000, printed in Aquivalenten PL glycol. According to this method the molecular weight with gelchromatographischer analysis is determined and a Polyäthylenglyko] as standard is used. Examples of these polymers are the copolymers of Hexaäthylenglykola] more lylmethyläther and mA] in acid mono ester of Butyltetraäthylen tetrapropylenglykol, hexadecimalethyl-closely] more ykolallylmethyläther and maleic acid mono esters of Methyltetraäthy] englykel, Dodecaäthylenglykolallylmethyläther and maleic acid mono esters of Methyloctaäthylenglyko], hexadecimal ethylen glycol allyl methyl ethers and maleic acid mono esters of Methyloctaäthylenglycol, Poly (n=22) ethylen glycol allyl methyl ether and maleic acid mono ester of Methyldodecaäthylenglykol, Poly (n=45) ethylen glycol allyl methyl ether and maleic acid mono ester of Methyldodecaäthylenglykol, Poly (n=18) ethylen glycol allyl methyl ether and maleic acid mono ester of Methyldodecaäthylenglykol as well as their Salze.
Preferential salts are the alkali, Erdalkaliund of ammonium salts as well as the salts of amines or Hydroxyalkylaminen.
In a preferential execution form of the invention one receives a particularly effective additive for the prevention of the loss at fluidity, if these polymers with certain Polycarboxylatsalzen are combined. The invention concerns thus also an additive for cement mixtures, which beside the mentioned polymers also at least a Polycarboxylatsalz from the group of the polymers contains respectable of copolymers of acrylic acid, Methacrylsäure, maleic acid, maleic acid anhydride, maleic acid mono ester. Per part by weight Polycarboxylatsalz contains the additive 0.1 to 10 parts of the Po] ymeres.
Preferably the Polycarboxylatsalz contains only acrylic acid, Methacrylsäure, maleic acid and maleic acid mono ester of monomer units from the group. In addition, other monomer units contained, e.g. alkyl acrylate can be respectable - methacrylat and styrene. Examples of suitable Polycarboxylatsalzen are copolymer salts of Methaorylsäure and Hydroxypropylmethacrylat, acrylic acid and Hydroxyäthylacrylat, Methacrylsäure and Methyldecaäthylenglykol methacrylat, styrene and Methyldeoaäthylenglykolmaleat, styrene and Butylmaleat, methyl hexadecimal ethylen glycol allyl ether and maleic acid, vinyl acetate and maleic acid, Methylvinyläther and Maleinsäure.
Preferential salts are the same as above for the polymers angegeben.
The edindungsgemässen polymers adsorb many more slowly on the cement particles than normal dispersing agents. Immediately after addition practically no adsorption takes place and remains the polymer molecules in the Flüssigphase, exercises thus no Dispergierwirkung on the cement particles. With the time, mostly after 30 to 60 minutes, the polymer adsorbs slowly on the cement particles and causes with the fact that they are dispersed. The fluidity of the appropriate cement mixtures is received in this way over longer time, which comes in a constant setting measure to the expression. If a Polycarboxylatsalz is added, this adsorbs forwards dern polymer on the cement particles. After approximately 30 to 60 minutes Iässt the Dispergierwirkung of this Polycarboxylatsalzes after and the polymer can adsorb then slowly and thus the cement particles disperse as well as the fluidity fördern.
Because in the last years the transportation times for finished concrete increased, the problem of the loss at fluidity becomes more acute. The addition one, additive according to invention prevents this Verlust.
The dosage of the additive depends very strongly on the loss at setting measure. This varied depending upon composition of the cement mixture, temperature, etc. so that no concrete data can be made. The specialist will be able to determine however easily, to receive which quantity of additives is necessary, in order a certain setting measure during pouring. At a concrete temperature of 20°C the dosage the polymere, without additive of Polycarboxylatsalz, from 0,01 to weight percentage will amount to, related to the cement weight. Even if the additive a Polycarboxylatsalz contains, the appropriate dosage from 0,05 to 5.0 weight percentage, related to Zementgewicht. is
The addition of the additive according to invention takes place favourably with mixing in the concrete factory. In addition, it can be admitted later. If the additive is given to finished concrete, the one water reducing means, in particular a supercondensor, receives one contains a high fluidity, which bleíbt over longer time received, which permits a more efficient work on dern building site and sGhliesslich a better quality of the received concrete product results in, because prevents the defects developing during hardening werden.
The cement mixtures, which contain the additives according to invention, in addition know any well-known water reducing means, e.g. Naphthalinsulfonat formaldehyde condensate, Melaminsulfonat formaldehyde condensate, Ligninsulfonat, Polycarboxylatsalz, Hydroxycarboxylat, Glucosaocharid, copolymers of geradkettigen or cyclischen Olefinen with 4-6 carbon atoms and insatiated dicarbonic acid anhydrides, enthalten.
In the following examples the parts parts by weight and the per cent weight percentage mean. The temperatures are in centigrades angegeben.
Different polymers with the designations FLPA-1 to FLPA-7 are used, whose structure is indicated in the following. The molecular weight (Mw) became by gelchromatographische analysis bestimmt.
FLPA-I: PL glycol allyl methyl ether maleic acid butyltetraäthylen tetrapropylenglykol mono ester, Mw = 15,000 FLPA-2: Hexadecimal ethylen glycol allyl methylätherMaleinsäure methyltetraäthylenglykol mono ester, Mw = 8,000 FLPA-3 " Dodecaäthylenglykol allyl methyl ether - maleic acid more methyloctaäthylenglykolmonoester, Mw = 15,000 FLPA-4: Hexadecimal ethylen glycol allyl methylätherMaleinsäure methyloctaäthylenglykol mono ester, Mw = 12,000 FLPA-5: PL glycol (n=22) allyl methyl ether - maleic acid methyldodecaäthylenglykol mono ester, Mw = 15,000 FLPA-6: PL glycol (n--45) allyl methyl ether - maleic acid methyldodecaäthylenglykol mono ester, Mw = 20,000 FLPA-7: PL glycol (n=18) - maleic acid methyldodecaäthylenglykol mono ester, Mw = 40,000 these polymers to cement mixtures, those are given to allyl methyl ether according to the quantitative proportions I and IL of the following table manufactured werden.
3 quantitative proportions water/cement sand/aggregate content in kg/m 3% % cement water I 63,4 49 320,203 IL 51,9 47 320,166 the assigned materials are normal haven] and cement (3 kinds in same quantities, spec. Gew.
3.16).
Fine aggregate: Mixture of Oi river sand and Kisarazu [and sand (spec. Thread 2,62, FM 2,71) rough aggregate: Tokyo Ome hard crushed sandstone (spec. Thread 2,64, ms 20 mm).
Also three Vergleichemiechungen are manufactured, one without additive (quantitative proportion I) and two with Supervefflüssiger (quantity hold back never II). The Superverflüesiger eingeeetzen to the comparison is:
BNSF: Naphthalinsulfonat formaldehyde Kondensationsprodukt MSF: Melaminsulfonat formaldehyde Kondensationsprodukt:
The Luffporengehalt is adjusted immediately after the mixing process in a mixer to 4,5 + 0.5% (volumes), by a means for the regulation of the Luftporengehaltee and/or a Schaumverhütungsmittel admitted wird.
The characteristics of the received concrete are examined after JIS A 6204. The results are in the tables 1 and 2 too finden.
Table 1 - Prüfungsresu [tate (Teli 1) additive setting measure in cm [air %] 2 according to type Dosierungl 0 min. 30 min. 60 min. 90 min.
Vergleiche1 without - 19,0 [2.0] 17,0 [2.0] 15,5 [1.8] 12,5 [of 1.7] examples 2 BNSF 0,50 18,0 [4.4] 10,5 [4.1] 6,5 [3.8] 4,0 [3.3] 3 MSF 0,60 18,5 [of 4.2] 9,5 [4.0] 6,5 [3.9] 4,0 [3.1] examples 1 FLPA-1 0,30 10,0 [4.0] 20,0 [4.2] 20,0 [4.3] 19,5 [4.9] in accordance with invention 2 FLPA-1 0,40 13,0 [4.6] 20,5 [4.2] 21,0 [4.6] 20,0 [4.8] 3 FLPA-2 0,20 14,0 [4.5] 24,0 [4.5] 23,0 [4.2] 22,5 [4.0] 4 FLPA-2 0.30 15,5 [4.7] 24,0 [4.0] 24,0 [3.9] 23,0 [4.0] FLPA-3 0,30 10,0 [4.4] 20,0 [4.0] 19,5 [4.3] 19,0 [5.0] 6 FLPA-3 0,40 12,0 [4.3] 22,5 [4.0] 21,0 [4.8] 21,0 [4.3] 7 FLPA-4 0,30 8,0 [4.5] 17,0 [4.3] 20,0 [4.3] 19,0 [4.5] 8 FLPA-4 0,40 9,0 [4.8] 19,0 [4.0] 22,0 [4.3] 21,5 [4.9] 9 FLPA-5 0,30 11,0 [4.8] 19,5 [4.3] 19,0 [4.0] 18,0 [4.0] FLPA-5 0,40 13,0 [4.4] 22,0 [4.0] 20,0 [4.2] 20,5 [4.3] 11 FLPA-6 0,30 12,0 [4.9] 19,0 [4.7] 20,0 [4.6] 18,0 [4.7] 12 FLPA-6 0,40 11,0 [4.5] 21,0 [4.3] 20,0 [4.0] 20,0 [4.6] 13 FLPA-7 0,40 5,0 [4.0] 8,0 [4.0] 10,0 [4.0] 12,0 [4.3] 14 FLPA-7 0,50 8,0 [4.0] 8,0 [4.0] 13,0 [4.2] 12,0 [4.2] 1st weight percentage related to cement 2nd air void content certainly with the help of a tilting mixer with 2 U/min.
Table 2 - Test results (Teli 2) additive setting measure of air setting time (h-min.) Type Vergleichs1 without examples 2 BNSF 3 MSF pressure strength after 28 days (kgf/crn2) dosage (cm) (%) beginning conclusion - 19,0 2,0 5-40 7-50 329 0,50 18,0 4,4 5-30 7-30 407 0,60 18,5 4,2 5-30 7-40 4 " 10 examples in accordance with invention 1 FLPA-1 0,30 10,0 4,0 10-00 12-30 489 2 FLPA-1 0,40 13,0 4,6 13-30 15-30 490 3 FLPA-2 0,20 14,0 4,5 15-30 18-50 482 4 FLPA-2 0,30 15,5 4,7 17-30 20-30 463 FLPA-3 0,03 10,0 4,4 9-00 11--30,475 6 FLPA-3 0,40 12,0 4,3 12-00 14-00 495 7 FLPA-4 0,30 8,0,4,5 1 0-00 13-00 494 8 FLPA-4 0,40 9,0,4,8 12-30 15-00 475 9 FLPA-5 0,30 11,0 4,8 8-30 1 0-00 485 FLPA-5 0,40 13,0 4,4 10-00 13--00,475 11 FLPA-6 0,30 12,0 4,9 7-30 9-30 494 12 FLPA-6 0,40 11,0 4,5 9-00 11 (30,515 13 FLPA-7 0,40 5,0,4,0 5-30 7-00 505 14 FLPA-7 0,50 8,0,4,0 6-00 8-00 488 from the table 1 one can infer that the values for the setting measure in the comparison examples 2 and 3 decrease with the time, while for the examples of the invention these values immediately after mixing rather low (8-15 cm), after 30 min. much more highly (19-24 cm) are and even after 90 min. do not decrease, i.e. remains the setting measure voli. The connections according to invention are thus suitably, around the fluidity from concrete mixtures to erhalten.
EXAMPLE 2 in this example different Polycarboxylatsalze as well as polymers is used by example 1. These salts have the designations PCAS-1 to PCAS-8 and their structure are as follows (the middle Molekulargewioht is printed as PL glycol equivalent and determined with gelchromatographischer analysis):
PCAS-I: Copolymer salt of Methacrylsäure - Hydroxypropylmethacrylat, Mw = 8,000 PCAS-2: Copolymer salt of Acry] acid - Hydroxypropylacrylate, Mw -- 6,000 PCAS-3: Copolymer salt of Methacrylsäure - methyl decaäthylenglykol methacrylat, Mw -- 20,000 PAS-4: Copolymer salt of StyroI Methyldecaäthylenglykol maleat, Mw = 15,000 PCAS-5: Copolymer salt of styrene - Butyl maleat, Mw = 10,000 PCAS-6: Copolymer salt of methyl hexadecimal ethylen glycol allyl ether - maleic acid, Mw = 10,000 PCAS-7: Copolymer salt of vinyl acetate - maleic acid, Mw = 7,000 PCAS-8: Copolymer salt of Methylvinyläther - maleic acid, Mw = 7,000 production of the mixtures:
To 100 parts of a 40%-igen aqueous solution of the Polycarboxylatsalzes under agitating with 20° are given to 50 parts of a 40%-igen aqueous solution of the polymer. The mixture is agitated during hours further, in order to receive a homogeneous solution. The pH is stopped with an aqueous soda solution to 7,0 and the solution is let stand during 24 hours. It results a solution according to invention A] to s 40%-ige aqueous Lösung.
In this procedure the mixtures indicated in table 3 become hergestellt.
Examination of the received concrete mixtures:
The mixtures FLCD-1 to FLCD-15 are mixed in the mixing proportion IL in accordance with example 1 with cement, sand, gravel and water and the Betonrnischungen, particularly regarding preservation of the setting measure is examined. For comparison example 1 the mixing proportion I is used in accordance with example 1, while the comparison examples 2-5 in the mixing proportion IL are manufactured. The assigned materials are those from example 1.
The concrete is examined in accordance with JIS A 6204. The results go out of the tables 4 and 5 hervor.
The air void content is stopped immediately after mixing to 4,5 + 0.5% (volumes), as air void those, a Luftporenbildner and/or a foam prevention means are admitted, so far notwendig.
From the table 4 it is evident that the values for the setting measure in the comparison examples decrease about 2-4% with the time, while the setting measure is in the comparison example 5 immediately after mixing low and according to table 3 mixture Polycarboxylatsalz mixing proportion Viscosität of a 40%-igen respectable polymer (on weight) solution in cpsl FLCD-1 PCAS-1: FLPA-1 1:1 380 -2 PCAS--2: FLPA-2 1:1 360 -3 PCAS-3: FLPA-3 1:0.3 470 -4 PCAS-3: FLPA-2 1:0.5 510 -5 PCAS-3: FLPA-3 1:1.5 470 -6 PCAS-4: FLPA-3 1:0.8 320 -7 PCAS-4: FLPA-4 1:1 420 -8 PCAS-4: FLPA-3 1:0.5 390 -9 PCAS-4: FLPA-5 1:0.5 530,-10 PCAS-4: FLPA-6 1:1 420,-11 PCAS-4: FLPA-7 1:2 630,-12 PCAS-5: FLPA-1 1:1 400,-13 PCAS-6: FLPA-3 1:1 300,-14 PCAS-7: FLPA-1 1:0.4 350,-15 PCAS-8: FLPA-4 1:0.5 360 1 the viscosity becomes 24 hours after mixing with a B-type Viskosimeter with 60 U/min.
with 20° gemessen.
min. strongly increases, whereby the setting measure remains during a long period. In the examples in accordance with invention the setting measure remains during a long period, with practically no loss, even after 90 min.
From table 5 it follows that concrete mixtures with the according to invention, the fluidity receiving additives comparable characteristics to normal concrete mixtures aufweisen.
Table 4 - Test results (Teli 1) 1 additive setting measure type Dosierung2 0 min 30 min Vergleichs1 without - 19,0 [2.0] 17,0 [of 2.0] examples 2 BNSF 0,50 18,0 [4.4] 10,5 [4.1] 3 MSF 0,60 18,5 [4.2] 9,5 [4.0] 4 PCAS-1 0,25 18,5 [4.0] 15,0 [4.0] FLPA-1 0,30 10,0 [4.0] 20,0 [4.2] in cm [air (%)]A after min 90 min 15,5 [1.8] 12,5 [1.7] 6,5 [3.8] 4,0 [3.3] 6,5 [3.9] 4,0 [3.1] 12,5 [4.0] 9,0 [4.5] 20,0 [4.3] 19,5 [of 4.9] examples in accordance with invention 1 FLCD-1 0,35 18,0 [4.4] 19,0 [4.0] 2 FLCD-2 0,20 19,0 [4.6] 19,5 [4.5] 3 FLCD-3 0,25 18,0 [4.7] 21,0 [4.7] 4 FLCD-4 0,20 18,5 [4.7] 20,0 [4.3] FLCD-5 0,30 19,0 [5.0] 20,5 [4.2] 6 FLCD-6 0,30 19,0 [4.9] 20,5 [4.3] 7 FLCD-7 0,30 18,0 [4.5] 20.0 [4.0] 8 FLCD-8 0,30 17,0 [4.0] 19,5 [4.0] 9 FLCD-9 0,30 18,0 [4.5] 19,5 [4.2] FLCD-10 0,30 18,0 [4.4] 20,0 [4.2] 11 FLCD-11 0,55 18,0 [4.6] 19,0 [4.7] 12 FLCD-12 0,30 17,0 [4.0] 20,0 [4.0] 13 FLCD-13 0,30 17,0 [4.5] 21,0 [4.2] 14 FLCD-14 0,30 19,0 [4.3] 19,0 [4.0] FLCD-15 0,30 19,0 [4.4] 20,0 [4.3] 19,0 [4.2] 18,5 [4.7] 18,5 [4.0] 18,0 [4.9] 20,0 [4.5] 18,5 [4.7] 20,0 [4.2] 19.0 [4.8] 18,5 [4.4] 18,5 [5.0] 20,0 [4.7] 18,0 [4.8] 19,0 [4.0] 18,0 [4.4] 19,0 [4.0] 18,5 [4.3] 19,0 [4.0] 18,5 [4.2] 20,0 [4.0] 18,5 [4.3] 21,0 [4.9] 20,0 [4.8] 19,0 [4.2] 17,0 [4.6] 20,0 [4.1] 20,0 [4.0] 18,0 [4.2] 17,0 [4.5] 18,5 [4.8] 16,5 [5.0] 1 it 2 in weight percentage related to cement 3 air void content becomes mixed in a mixer in a tilting mixer with 2 rpm. determines table 5 - test results (part of 2) additive setting measure type dosage (cm) Vergleichs1 without - 19,0 beispielse 2 BNSF 0,50 18,0 3 MSF 0,60 18,5 4 PCAS-1 0,25 18,0 FLPA-1 0,30 10,0 air setting time (h-min) pressure strength after 28 days (%) beginning conclusion (kgf/cm2) 2,0 5-40 7-50 329,4,4 5-30 7-30 407,4,2 5-30 7-40 410,4,0 6-10 8-30 467,4,0 10-00 12-30 489 Beispieie in accordance with invention 1 FLCD-1 0,35 18,0 2 FLCD-2 0,20 19,0 3 FLCD-3 0,25 18,0 4 FLCD-4 0,20 18,5 FLCD-5 0,30 19,0 6 FLCD-6 0,30 19,0 7 FLCD-7 0,30 18,0 8 FLCD-8 0,30 17,0 9 FLCD-9 0,30 18,0 FLCD-10 0,30 18,0 11 FLCD-11 0,55 18,0 12 FLCD-12 0.30 17.0 13 FLCD-13 0,30 17,5 14 FLCD-14 0,30 19,0 FLCD-15 0,30 18,0 4,4 6-30 8-30 460,4,6 6-5O 9-50 470,4,2 6-30 8-40 463,4,7 6-55 9-30 486,5,0 6-10 8-30 450,4,9 7-00 9-10 460,4,6 7-00 9-00 472,4,0 6-30 8-40 453,4,5 6-30 8-15 465,4,4 7-00 9. - 00,475,4,6 6-50 9-50 494,4,0 6-00 8-10 455,4,5 6-00 8-00 460,4,3 6-30 8-20 445,4,6 6-40 9-00 470 A polymeric composition which reduces the loss of flowability of a cementitious composition comprises at least one polymer as a salt thereof having the form of a copolymer of (a) a maleic anhydride half-ester with a compound of the formula I RO(AO)mH (I) where R is a C1-20alkyl group, A is a C2-4alkylene group and m is an integer from 2-16; and (b) a monomer having the formula II CH2=CHCH2-(OA)nOR (II) where n is an integer from 1-90. In a preferred embodiment, there is present a polycarboxylate salt which is at least one polymer or copolymer comprising at least one of the monomers acrylic acid, methacrylic acid, maleic anhydride, maleic acid and maleic acid monoester, polymer and polycarboxylate salt being blended in the proportion of 0.1-10 parts of weight of polymer per part of polycarboxylate salt. Cementitious compositions such as concrete in which such polymeric compositions are included maintain their slump properties. 1. Additive for cement mixtures, containing at least a polymere connection or a salt of it, which is a copolymer from a) a half ester of the maleic acid and a connection of the formula I RO (AO) mH (I) where R a Cl-2o-Alkylgruppe, A a C2. - 4-Alkylengruppe and m a number from 2 to 16 mean, and b) a monomer of the formula IL CH2=CH-CH2 (OA) nOR (11) where R mean a C1-2o-Alkylgruppe, A a C2-4-Alkylengruppe and a n a number from 1 to 90. 2. Additive in accordance with requirement 1, by it characterized that the polymere connection exhibits an average molecular weight Mw from 5000 to 500,000, expressed in Aquivalenten PL glycol and by gelchromatographische analysis determines. 3. Additive gernäss requirement 1 or 2, by the fact characterized that the polymere connection is a copolymer of hexadecimal ethylen glycol allyl methyl ether and Maleinsäurernonoester of Butyltetraäthylentetrapropylenglykol, hexadecimal ethylen glycol allyl methyl ethers and maleic acid mono esters of Methyltetraäthylenglykol, Dodecaäthylenglykolallylrnethyläther and maleic acid mono esters of Methyloctaäthyienglykol, hexadecimal ethylen glycol allyl methyl ethers and maleic acid mono esters of Methyloctaäthylenglykol, PL glycol allyl methyl ether with 22 ethylen glycol units. .und maleic acid mono esters of Methyldodecaäthylenglykol, PL glycol allyl methyl ethers with 45 Athylenglykoleinheiten and maleic acid mono esters of Methyldodecaäthylenglykol or a salt of it. 4. Additive gernäss one of the requirements 1 to 3, by the fact characterized that beside the polymere connection at least a Polycarboxylatsalz from the group of the polymers respectable maleic acid, maleic acid anhydride and maleic acid mono esters contain Copolyrnere of acrylic acid, Methacrylsäure, ist.
Additive in accordance with requirement 4, by the fact characterized that per part by weight Polycarboxylatsalz 0.1 to 10 parts the polymere are contained. 6. Additive in accordance with requirement 4 or 5, by the fact characterized that the Polycarboxylatsalz is a copolymer salt of Methacrylsäure and Hydroxypropylmethacrylat, acrylic acid and Hydroxyäthylacrylat, Methacrylsäure and Methyldodecaäthylengiykolmethacrylat, styrene and Methyldecaäthylenglykolrnaleat, styrene and Butylmaleat, methyl hexadecimal ethylen glycol allyl ether and maleic acid, vinyl acetate and maleic acid, Methylvinyläther and maleic acid. 7. Zusatzrnittel gernäss one of the preceding requirements, by the fact characterized that the polymer salt is respectable Polycarboxylatsalz an alkali, a Erdalkalioder ammonium salt and/or a salt of Arninen or hydroxyalkyl amines. 8. Use of a Zusatzrnittels gernäss one of the requirements 1 to 7 for the prevention of the loss at FIiessfähigkeit of cement mixtures, which consist of water, cement and further additives. 9. Cement mixtures, which consist of water, cement and further additives, and an additive in accordance with one of the requirements 1-7 enthalten. cement mixtures gernäss requirement 9, the aggregate enthalten.