CA2091169A1

CA2091169A1 - Homogeneous tar and cementitious composition and process

Info

Publication number: CA2091169A1
Application number: CA 2091169
Authority: CA
Inventors: John F. Schneider; Kurt A. Schneider
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-09-07
Filing date: 1991-08-29
Publication date: 1992-03-08
Also published as: JPH06500528A; DE69111073D1; CZ35293A3; EP0547160A4; US5116420A; AU646370B2; DE69111073T2; NO930814D0; ATE124675T1; EP0547160B1; DK0547160T3; AU8744591A; FI930928A; NO930814L; EP0547160A1; GR3017503T3; PL298543A1; WO1992004292A1; HU9300597D0; BG97606A

Abstract

Improved cementitious compositions having increased flexural, tensile and shear-bond strength, increased wear resistance, decreased water permeability and enhanced workability than previous cement compositions, which are prepared with water treated with an emulsified tar component, and preferably a residual amount of sodium tripolyphosphate, are provided. Methods of forming shaped articles therefrom are also provided.

Description

VO 92/04292 2 Q ~ 9 PCI'/US91/06204 HO~IOGENEOUS_TAR AN~
COMPOSITIO~ AND PROCESS
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-~iPld of the Invention - Tha present invention is directed to improved cementitious compositions having increased flexural, tensile and shear-bond strength, increased wear resistance, decreased permeability, and enhanced workability ~han previous cement compositions. More partlcnlarly the invention is directed to cementitious compositions prapared with an aqueous premix containing an emulsifier system and tar component and to methods of rorming shapad articles therefrom. Preferably, the aqueous premix used to prepare the cementitious compositions also contains a residual amount of sodium tripolyphosphate.
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Back~round of the Invention Inorganic cements exhibit characteristic properties of setting and hardening when mixed with water to form a paste. They are capable of joining ;j rigid solid masses into coherent structures. Inorganic cements can be divided into hydraulic and nonhydraulic types according to the way in which they set and harden.
For example, hydraulic cements are capable of setting and hardening in air and under water, whereas nonhydraulic cements are only capable of hardening in ~`~30 air. See Z. D. Jastrebski, The Nature and Propertiès of Enqineerinq Materials, 2d. Ed., John Wiley & Sons, New Yo~k (1977) at 356, the disclosure of which is incorporated by reference herein.
;!The most widely-used hydraulic cement is so-called Portland cement, which is obtained by heating an intimate mixture, composed mainly of calcareous and ;~argillaceous materials, or other silica, alumina, and iron-oxide bearing materials, at a clinkering temperature of about 1400~C. The partially sintered ` ~ ' ' ` ' .

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2091~

material, called clinker, is then ground to a very fine powder. After mixing with water, a hardened amorphous mass is formed consisting primarily of calcium-silicate hydrate (C-S-H) which, like other gels, contains a network of capillary pores and gel pores. The total porosity of a typical hardened Portland cement paste is about 30-40% by volume, having a very wide pore-size distribukion ranging from 10-0.002 ~m in diameter. The gel porosity, consisting of very small pores, below 0.01 ~m, is about 26%, with the remaining porosity due to capillary network. See z. D. Jastrebski, su~ra, at 356-61.
Portland cement formulations may also contain ; additional additives. For example, small amounts of ~-~ 15 calcium sulfate in the form of gypsum or anhydrite are added during grinding of the raw materials to control the setting time and enhance strength development of Portland cement. Cement pastes are sometimes impregnated with liquid organic monomers or liquid ~` 20 sulfur and polymerized to produce polymer-impregnated ~; concrete. See 5 Kirk-Othmer Encyclopedia of Chemical Technoloqy, 3rd. ed., John Wiley & Sons, New York (1978) at 163, the disclosure of which is incorporated by reference herein. Other additives include water reducers, plasticizers, air entrainment and anti-foaming additives, silica fines, fly ash, polymer latexes and the like.
Previously, in Applicants~ U.S. Patent No.
4,930,428, the discIosure of which is herein incorporated by reference, a high strength concrete ~ composition formed from water treated with about 0.5 to ; 100 parts per million (ppm) residual sodium tripolyphosphate (STP) was described. Surprisingly, the concrete composition was found to exhibit higher strength, density, and lesser porosity than conventional concrete compositions. This composition is a significant improvement over conventional concrete.

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':' 2~9~16 9 However, as with conventional concrete, several disadvantageous properties remain.
Conventional concrete is not flexible or elastic.
Thus, when conventional concrete is subjected to compressive, :elsxural, tensile and/or shearing forces, it breaks or cracks after undergoing relatively minor deformation. Tn addi-tion, conventional concretes are relatively permeable and porous, and accordingly, often transport and :-etain a high degree of trapped mo~sture.
0 Thg tQndsncy of conventional concrete to retain ~- moisturs can ~resent particular problems in hot or cold climates. For example, moisture trapped in concrete during a period of freezing temDeratures will expand and form is3 c~Ts als which of~n crack the concrete. This phenomenon, -re ferred to as frost damage is particularly prevalent in areas subject to multiple freeze-thaw cycling. In such areas, the usable life of conventional concrete is often greatly reduced by this phenomenon.
~- Furthermore, in an effort to overcome the tendency of conventional concrete to break or crack in these climates, conventional concrete is air entrained by the addition of various additives which increase the trapped air in the composition.
The relatively high permeability of conventional concrete also limits the varieties of fly ash which can be added to the compositions. For example, only so called "clean" fly ashes, such as those ~' obtained from coal-fired power plants can be employed in conventional concrete mixtures. Fly ashes, which may contain organic or inorganic contaminants, such as those which are obtained from the combustion of refuse, cannot be employed, since such contaminants have a tendency to leach out of conventional concrete when it is subjected to rain or melting snow.
Finally, conventional concrete can be difficult to work with. .~fter being poured, conventional concrete often requires significant screeting and troweling to W O 92/04292 ~ ~ 9 1 ~ '3 PC~r/US91/06204 obtain a smooth, usable surface. Furthermore, the tendency of conventional concretes to "bleed" water to the surface of the mass often aggravates the ability to ; obtain a smooth surface. In fact, if the surface of the concrete is troweled too extensively, it will dry to a loose, powdery mass which must be replaced.
Therefore, there is a need for cementitious compositions which exhibit substantially greater fle~ural, ~ensile and shear-bond strength, decrease -~ 10 permeability and which provide enhanced workability relative to cement compositions currently available.
~- Thare is also a need for methods of improving "` the flexural, tensile and shear-bond strength, and other desirQd propertles of cementitious composition~ and lS articles made from these compositions.
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Accordingly, it is an object of the present invention to provide cementitious compositions which are ` substantially more flexible, tensile and shear resistant, less permeable, and provide enhanced ~0 workability than cement compositions previously known.
Furthermore, it is an object of the present invention to also provide cementitious compositions which, through ~`~ the preferred addition of sodium tripolyphosphate, also display many of the advantageous properties described in Applicant's U.S. Patent No. 4,930,428.
In addition, it is aIso an object of the present invention to provide an aqueous premix for use in improving the flexural, tensile and shear-bond strength, as well as other desired properties, of cementitious compositions.
Finally, it is also an object of the present ; invention to provide a method of manufacturing shaped articles from the above compositions.

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Summary of the Invention The forgoing objects are accomplished by a cementitious composition formed from a mixture of the following ingredients: about 0 to about 85 percent by weight of aggregate, about 7 to about 90 percent by weight of dry cement, about 3 to about lO percent by weight of aqueous premix, and about 0 to about S0 percent by weight of fly ash, the percentages by weight being ralacive to the weight of the total composition, and the ratio of the a~ueous premix to dry cementitious materi~ls (i.e. dry CemQnt ~nd fly ash) being sufficient to give a castable mix. The aqueous premix is a highly dispersed mixture of water, an emulsifier system and a tar COAm Onen ~ .~he-ein the tar component constitutes from about O.iO IO 25.0 weight percent of the aqueous premix. In addition, the aqueous premix preferably contains from about O.S to about 180 parts per million of residual sodium tripolyphosphate.
The present invention is also directed to an aqueous premix for concrete formed from a mixture of the following ingredients: about 0.05 to about 15.0 percent by weight of an emuIsifier system, from about O.lO to about 25.0 percent by weight of a tar component, and about 65 tO about 99 percent by weight of water, wherein the weight percents of the ingredients are relative to the total weight of the premix. In ~ddition, the premix preferably contains the above-mentioned proportion of residual sodium tripolyphosphate.-The premix constitutes a substantially uniformly distributed dispersion of the tar component in water. Preferably, it is of colloidal dimensions and especially preferably, it is substantially stable against settling, separating or otherwise becoming a non-disperse mixture.
In addition, the present invention is also directed to a process for manufacturing a cementitious shaped article. The process lncludes the steps of .
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mixing water with the emulsifying system and the tar component in appropriate proportions as mentioned above to form an aqueous premix; forming a fluid cementitious mixture by mixing the aqueous premix with aggregate, dry cement, and optfonal fly ash; pouring the fluid cementitious mixture into a casing; and allowing the ~ mixture -to harden into the cementitious shaped article. -;~ In addition, the process for manufacturing cementitious ~; shaped arLicles preferably will include mixing sodium tripolyphosphate in the aqueous premix, such that the water is softened, ~nd the residual proportion of sodium tripolyphospha~e mentioned above remains in the aqueous premix.
'. fu-_~e~ object of the presant invsntion is to provide a procass for increasing the flexural, tensile ~- and shear-bond strength, while decreasing the permeability of a cement composition. The process includes the step of forming the cement composition from a combination of dry cementitious ingredients and the ; 20 aqueous premix containing water, the emulsifier system ; and the tar component in the proportions mentioned above. In addition, it is preferred that the aqueous ~, premix further contain an appropriate proportion of residual sodium tripolyphosphate as mentioned above.
Finally, the present invention also provides a shaped article formed by a process including the steps of mixing water with the emulsifier system and the tar component to form the aqueous premix in the appropriate proportions mentioned above; forming a fluid cementitious mixture by mixing the appropriate, above-~ mentioned proportions of the aqueous premix with ;; ; aggregate, dry cement and fly ash; and pouring the fluid cementitious mixture into a casing so that the mixture hardens into a shaped article. As with the previous ~;~ 35 embodiments, preferably the aqueous premix further contains from an appropriate, above-mentioned proportion of residual sodium tripolyphosphate.

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~092/04292 2 ~ 9 1 t 6 9 PCT/US91/0620~

Advantageously, the processes and cementitious compositions and shaped articles formed therefrom according to the present invention echibit surprisingly increased flexural, tensile and shear-bond strength, increased wear resistance, decreased permeability and enhanced workability over cement compositions or concretes not incorporating an emulsified tar component and preferably a residual amount of sodium ~` tripolyphosphata.
, ~ 10 De al7 ~d O~scri~tio~ o rh~ .In~ntion The present invention provides a camentitious composition produced from a mlxture of dry cement, aggr~gate, optiona.l f l7y 2sh ard a _~r componenL in an ~;~ 15 aqueous SO1ULiOn ( aqueous premi,). In a preferred aspect, the aqueous premix also contains a residual amount of sodium tripolyphosphate (STP). More particularly, the present cementitious composition is formed from a combination of ingredients including about 0-85 weight percent aggregate, about 7-90 weight percent dry cement, about 3-10 weight percent of aqueous premix, and about 0-50 percent fly ash. Preferably, the combination of ingredients includes about 30-85 weight percent aggregate, about 7-70 weight percent dry cament, about 4-8 weight percent aqueous premix, and about 1-30 weight percent fly ash. More preferably, the combination of ingredients includes about 70-82 weight percent aggregate, about 9-25 weight percent dry cement, about 5-9 weight percent aqueous premix, and about 1-4 weight percent fly ash. An especially preferred combination of ingredients contains about 75-80 weight percent aggregate, about lQ-15 weight percent dry cement, about 6-8 weight percent aqueous premix, and about 2-3 weight percent fly ash.
The "aqueous premix" is produced by first adding an emulsifier system and then the tar component to the water to be mixed with the dry, cementitious , : ;, , -.. :. . . . .

W092t04292 ~ PCT/US91/06204 ingredients of the composition, i.e. the aggregate, dry cement, and optional fly ash. Preferably, the tar component constitutes from about 0.1-25.0 weight percent of the aqueous premix, more preferably from about 5.0-12.5 weight percent, and most preferably about 7.0-9.0 weight percent of the aqueous premix component of the present invention. Expressed as a percent by weight of.
the total composition, the tar component is from about 0.01-1.7 weight percent, mors prsferably from about 0.3-0.8 weight percen~, and most preferably about 0.6-0.7 . weight percent of the total weight of the composition.
Tha emulsilier system includes one or more primary emulsifying, surfactant or dispersing agents as ; well as optlonal s9cond2ry ag3n~3 in amounts sufriciant 15 to produc~ a substan.~ally unirorm, extremely fine . macromolecular dispersion of the tar component in the water. Preferably, the emulsifier system is about O.OS
::;. to about 15.0 weight percent, more preferably about 0.1 ~: to about 12 weight percent, most preferably about l to about 10 weight percent relative to the weight of the premix.
Further, the aqueous premix utilized in the present invention also will preferably contain an excess of STP o-~ex the amount that is effective -to soften the water to be mixed with the tar component, emulsifier system and dry, cementitious ingredients of the ; composition. The addi+ion of excess STP produces an aqueous premix having a residual amount of STP, ; preferably at about 0.5-180 parts per million (ppm).
More preferably, the aqueous premix will contain about 15-22- ppm residual STP and most preferably, about 18-21 ppm residual STP.
Sodium tripolyphosphate (Na5P3OlO), a widely-used water-softening agent, is the sodium metal salt of an anion of the general formula [P o3~+l](~+2)~, where n = 3.
:~ Sodium tripolyphosphate (STP) is a linear polyphosphate ;~ . which can be prepared by the molecular dehydration of ' ~.
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; mono- and disodium phosphates. See The Merck Index, 10th Ed., M. Windholz et al., eds., ~exck & Co. (1983) at Entry 854~, the disclosure of which is incorporated by reference herein. For the purposes of this invention, it is desirable to combine this polymeric form of STP into the aqueous premix before incorporating the tar component, emulsifier system and dry ;~ ingredients.
As used herein, the tar component can be any combination of a variety of bituminous materials as ;~ ~ defined in American Society for Testing and Materials (ASTM) Standard D8-89, the disclosure of wnich is herein incorporated by reference, which are composed of mi~turss of IJarious polynucleæ z_omatic c^mpounds.
Suitable bituminous materials ,/nich may D2 used for the formulation of the aqueous premix include, without limitation, petroleum asphalt derived from refining processes (e.g., straight reduced asphalt, thermal cracked asphalt, air blown asphalt, propane precipitated asphalt), native asphalt with varying mineral contents (e.g., Gilsonite, graphamite, glance pitch, Bermudez and Trinidad deposits), heavy oil rubber incorporated bitumens (i.e., rubber dispersed in any of the present bituminous materials), resin incorporated bitumens (i.e., resin dispersed into any of the present bituminous materials), coal tars, oil tars, pitches, tall oil pitches and other pyrogenous tar distillates and associated derivatives from water-gas, wood, peat,-bone, shale, rosin and fatty acid tars. In addition, it will be appreciated that any source of polynuclear aromatic compounds, whether natural or synthe~ic~ is considered within the scope of the present invention.
Examples include polybiphenyls, fused anthracene compounds, phenanthracene compounds, benzo-substituted naphthalene, acenaphthalene and similar polyaromatic liquid, viscous liquid or solid compounds.
Particularly preferred bi~uminous materLals -.:. ' : . .

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wn 92/04292 PCT/US91/06204 according to the present invention are coal tars and their derivatives, which are viscous black to brown liquids resultins from the destructive distillation of bituminous coal at temperatures ranging between 450-1200C. For a more thorough discussion of themanufacture and composition of coal tars, see I9 Kirk-Othmer 3nc~clopsdi2 ?f Chemical_Technoloq~, 653-682 (2nd ed. 1~69), the dlsclosure of which is incorporated herein by ~a~erance.
~- 10 TAe 3mulsiIisr sys~em of the aqueous premix ~ according to ~he present invsntion contains a sufficient -~ amount of a primary emulsifying, surfactant or dispersing agent to disperse the bituminous materials into the .7a~:- 0_ he a'TUeCU5 ~.-3m', component so as to form an "oii-in-wa-cQr type smuision". In ganeral, primary emulsifying agents utili~ed with the bituminous materials can be one or more anionic, cationic or nonionic surface active agents which are incorporated as a total mixture at the proportions mentioned above for the emulsifying system. Furthermore, secondary agents including various clays such as bentonite montmorillonite, illite, atapulgite, fullers earth, diatomite, kaolin and zeolite can optionally be combined ; into the premix to serve as shearing, bulking, dispersing and emulsifying agents. The weight percentages of clay relative to the premix weight will range from about 0 to 80, preferably about 10 to 40, most preferably about 25 percent, this weight percentage being in addition to the weight percentage of 0.01 to 25 percent apportioned for the primary emulsifier, surfactant or dispersing agent. Acids, alkalis, salts, higher fatty acids, protective colloids or the like in appropriate functional amounts relative to the amount of primary emulsifier present can also be used to emulsify ; 35 bituminous materials in water in conjunction with the primary emulsifiers. In general, an acid is used primarily with cationic and/or nonionic surface active :,~
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~ O 92/04292 2 ~ ~ ~ 1 6 ~ PC~r/US91/06204 agents; an alkali is used primarily with anionic and/or nonionic surface active agents; and salts can be utilized with all classes of surface active agents.
Furthermore, the higher fatty acids may also contribute to the emulsification of the bituminous materials.
Examples of cationic emulsifiers include mainly higher alkyl alkylene polyamines, higher alk71amines, `~ higher alXyl polyaminoethylene imidazolines, the polyethoxylated or polyaminoimidaæoline dsri~Jativss OL
these compounds and the acid salts and quaternar~
ammonium salts of the above-mentioned ~olyamine compounds.
Cationic emulsifiers can also be ussd in conjunction sYith a nonionic emulsl -i3-. _n add ~i on, acids such as hydrochloric acid, sulfonic acid, acetic acid and the like, and water-soluble salts such as the halides of the alkaii metals and alkaline earth metals and the like may also be used in conjunction with these cationic emulsifiers. Furthermore, protective colloids such as methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, gelatin, a salt of a lignin amine, a polyoxyethylene polypropylene glycol ether or the like can also be utilized.
Examples of typical anionic emulsifiers include alkali salts of casein, fatty acid soaps, alkali salts of a sulfuric acid ester of a higher alcohol, sodium alkylbenzene sulphonate, sodium alkylnapththalene sulphonate, polyoxyethylene sulphonate, polyoxypropylene sulphonate the mixed polymers thereof the di and tri sulphonate derivatives thereof and similar carboxy or sulfonoxy functionalized fatty compounds. Alkalis such as NaOH, KOH, NH40H and water-soluble salts of an alkali metal may be used in conjunction with the above anionic emulsifiers.
Examples of nonionic emulsifiers include polyoxyethylene higher alcohol ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, - .

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WO92/04292 2 ~ 9 ~ , 3 PCT/US91/06204 polyoxyethylene alkyl ethers, glycerin fatty acid esters, propylene glycol fatty esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty esters, polyoxyethylene oxypropylene block polymers and the like. In addition, the same acids, alXalis, salts or protective colloids as can De used in cationic or anionic emulsions may bQ used with a nonionic emulsion. -Examples of protective colloids which can be utillzed with nonionlc emulsiriers lnclude carboxym2thyl cellulose, methyl ce~lulo 9, hydroxyethyl cellulose, ~ polyvinyl alcohol, lignin sulphonate, polvocyethylene ;~ polypropylene glycol e-th2r and -tha li'ca.
Preîerred emulsifiers of the preferred coal tar bituminous materials accord-ng r.o thQ n-eserLt nvention include the an onic su _acLants or emulaiFiers such as the mono, di and trisulphonated fat~y acids or alcohols as well as the mono, di and tri-sulphonated polyethoxy, polypropoxy and mixed polymer compounds. Particularly preferred amony these are the anionic emulsifiers, either alone, or in combination with less than a majority proportion of the nonionic polyethoxy, polypropyl and polyetholypropoly alcohols and esters mentioned above.
In addition to the tar component, emulsifier system and water, the aqueous premix according to the ; present invention may also contain other additives. For example, the tar component may also include smaller quantities of an acrylonitrile, butadiene or styrene ; copolymer or other rubberizing agents, as well as various wetting, pigmentation and setting agents.
A particular embodiment of the combination of tar component and primary and secondary emulsifying agents utilized in the premix of present invention is commercially available in the form of driveway, pavement or roofing sealant compositions. For example, coal tar pitch emulsions are commercially available from a wide variety of sources, including without limitation, ~och . . .

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` W092/04~92 2 ~ 9 1 1 6 9 PCT/US91/06204 Industries, Inc. of Wichita, Kansas, American Stone-Mix, Inc. of Baltimore, Maryland, The ~rewer ~ompany of Cincinnati, Ohio and Seal Master Corporation of xsnt~
Ohio. In addition, it will be appreciated that other commercially available bituminous emulsions, T~hich are also employed as driveway, pavement or roofing sealers, can be utilized as the tar component in the c~mentitious compositions of the present invention.
When employing commercially available coal ~ar emulsions to form the aqueous pxemix utilized in the compositions according to the present inventlon, it is preferred that an emulsion containing from aboul 20-80 weight percent solids, prefera~ly 40-70 weight percent solids, and most preferably about 50 ~sight oers3nt lS solids be employed. The solid components of thesa commercial emulsions typically include tar pitch solids and various clay particles, which are primarily aluminous silicates, in approximately equal proportions.
Thus, from about 20-80 weight percent, and preferably 50 weight percent of the commercial coal tar emulsion is water.
In utilizing a commercial coal tar emulsion to prepare the aqueous premix component of the present invention, it will be appreciated that approximately 50 weight percent of the commercial emulsion is water and 50 weight percent contains the solid components, with only 50 weight percent of these solids being the preferred emulsified coal tar component, and the other solid component being composed primarily of various clays. Accordingly, it will be further appreciated that appropriate adjustments are to be made in the formulations of the cementitious compositions of the present invention to ensure that the preferred amounts of water and tar component are incorporated therein.
For example, in contrast to a concentrated emulsified coal tar, the volume of water already present in the commercial coal tar emulsion is appropriately considered .

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2 n ~ -3 when calculating the total volume of water needed to form the aqueous premix component of the present - invention.
The "dry cement" of the present invention is the common, dry, powdery csmentitious starting material or "dry mix" that is typically mixod ~q~th T.1ater to form : a cement paste. The p-esent composil-ion includes about 7-90 ~eight percent of dry csmsnt, pref2rabl~ about 9-15 weight percent. In one êmbor1-men-_, tlle r2tlo o~ dry cement to aqueous prem.i~ iJ abol~t ~ to about l:l, preferably about ~-l to ~bOllt I . 5: 1, under conditions adjusted so that -the amounts OL dry cament and remaining ingredients are sufflcient to ~rovide the sLurry flo~
properties app-opria _ to o-:.~ a -asta_le mix.
The dry cament to be mixed .~ich the aqueous premix is preferably of the type kno~n as Portland cement, but may include any conventional dry cement, including those defined in American Society for ~esting and Materials (ASTM) Standard C-150, the disclosure of 20 which is herein incorporated by reference. While any.of the commercially available Portland cements can be conveniently used, a preferred chemical composition of a dry Portland cement useful in the present high-strength cement composition is the Type I mixture OI Portland ement shown ~n Table 1 below:

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.~ YO 92/04292 ~ P ~ /US91/06204 Table 1 - Dry Portland Cement Composition Approximate Component Weight %

Tricalcium silicate (3CaO SiO2): 45 - 50 , Dicalcium silicate (2CaO SiO2): 22 - 27 Tricalcium aluminate (3CaO A12O3) 10 - 15 ; Tetracalcium aluminoferrite (4CaO Al2O3Fe2O3): 5 _ 10 Calcium sulfate (CaS04): 2 - 4 Calcium oxide (free CaO):0.5 - 1.0 Magnesium oxide (free MgO): 2 - 4 Ignition Loss 0.5 - 2.0 _ _ The "aggregate" is any combination of clear particulate natural minerals, such as crushed stone, sand, or the like, but does not include any substantial amount of soil or dirt. In addition, the ~aggregate"
may include man-made components such as rubber powders, glass beads, micro balloons, resin foams, plastic particles, fiberglasses or various metal shapes.
The "fly ashn is the particulate, non-combustible by-product of various combustion processes, including without limitationj the burning of coal, refuse and other combustible materials. The addition of fly ash to the dry cement and the aggregate is optional in the present invention.
A particularly preferred formulation of the present composition is formed from a combination of ingredients including about 3000-3100 pounds of aggregate, about 450-550 pounds of dry "Portland"

, 2~91~ ~9 cement, about 80-110 pounds fly ash, and about 240-260 pounds of water treated with the tar component comprising from about 5.0-8.0 weight percent of the aqueous premix. Furthermore, the water used to form the aqueous premix should preferably be treated witn sodium tripolyphosphate (STP) so as to relain about 5 to 50, especially 18-21 parts per million of residual S P.
The present composition may also be mixsd as a castable cementitious composition. These cempositions ; 10 generally contain more dry Portland c3msnc -~han ch3 usual poured compositions, and are used commercially, for example, for manuracturing culvarts. ilhen a casting composition is formed from aqueous premix according to the present invention, it is bel i3ved ~ha~ '_'n~ ~mOlln-, O f dry Portland cemant needed may be l-ss tll2il til3 typic_l amount employed. When a typical amount (e.g., about 9 ; to 30 weight percent) of dry Portland cement is employed in combination with aqueous premix, the res~lting mixture becomes too thick to cast. Thus, an effective high flexural-strength castable cementitious composition according to the present invention may be formed by employing about 8-20 weight percent dry Portland cement, about 5-20 weight percent aqueous premix, about 0-85 weight percent aggregate, and optionally about 0-50 weight percent fly ash.
The manner in which the aqueous premix modifies the macromolecular structure of the cementitious composition so as to increase the flexural and tensile strength relative to ordinary concrete is not known.
While they are not intended as limitations or parameters of the present invention, several theories may explain this phenomenon, however. Inasmuch as the non-polar organic tar component and the electrostatically interactive inorganic complex salt cementitious component are immiscible, it is believed that the action of the emulsifier system and the preferred STP produces a highly dispersed amorphous tar component within the ~, . ,., ~ - . -.
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~~V092/04292 2 ~ 91 I 6 9 PCT/US91/06~04 greater proportion of semicrystalline cementitious component. The tar dispersion has colloidal or macrocolloidal dimensions so that the resulting structure is composed of highly disperse macromolecular domains of the tar component throughout the reticulated semicrystalline matrix of the calcium aluminosilicate cementitious component. The domains elasticize the faults of the matrix so that mechanical and thermal stresses on the matrix become dissipated by the "give"
of the organic domains. It is also possible that the pi electron orbitals of the polyaromatic compounds in the tar domain interact as induced dipoles with the electrostatic charges of the inorganic matrix. The emulsifier system and aspecially the STP may facilitate this dipolar interaction. The result is a remodeling of the matrix faults so that mechanical and thermal stress is dissipated as mentioned above.
The present invention also provides a process for manufacturing a shaped article. The initial step in the process involves treating water first with ~he emulsifier system and then with the tar component. The proportion of emulsifier system is about 0.05 to about 15.0 weight percent, more preferably about 0.1 to about 12 weight percent, most preferably about 1 to about 10 weight percent relative to the weight of the premix. The proportion of the tar component is from about 0.1-25.0 ~` weight percent, preferably 5.0-12.5 weight percent, and most preferably about 7.0-9.0 weight percent of the aqueous premix. In addition, the water should be preferably treated with an excess ,mount of sodium tripolyphosphate (STP). The "excess amount" is enough to provide a residual amount of STP in the water in addition to the amount that softens the water by solubilizing the metal salts present therein. This residual amount of STP can be from about 0.5-180 parts per million parts of the aqueous premix, preferably about 5-50 ppm, more preferably about 15-22 ppm, and .

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W092/04292 2 ~ ~ ~16 -' PCr/US91/06204 most preferably about 18-21 ppm. However, amounts exceeding approximately 180 to 250 ppm of residual STP
should be avoided. It is believed that these higher amounts of STP begin to cause other reactions in the cementitious composition which can lsad to its e~enLual breakdown or decomposition.
Following the addition OL the tar component, emulsifier system, and preferably STP, the aquaous premix is mixed with dry, cementitious ingredi3nL3 ~;~hich include dry cement, aggregate, and op~iona~ :E1~ 79il ~0 form a fluid cementitious mixtura or p2sts ~i ing ;n~y be performed by any means and for any length of '~_mG
which results in the formation of an e~Jenl~ mixerl, homogenous mix ure, bu-t most t ?ica~ ; is r ~-_ ~m_d by means of a rotating drum arrangamant such as an industrial cement mixer. The typical mixing time for a 4000 pound batch of cement is about 90 seconds when the concrete is mixed in a batching plant, and about 9 minutes when the mixing occurs in a truck having a rotating drum.
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Whén STP is added to the aqueous premix containing the tar component and emulsifier system, the aqueous premix must be mixed with the dry cement, aggregate, and optional fly ash within a period of time effective to prevent a substantial reduction of the flexural, tensile and shear-bond strength-enhancing, and other beneficial effects of the STP in tha aqueous premix. Preferably, the aqueous premix is mixed with the dry cement, aggregate, and optional fly ash within about 4 days from the addition of the STP to the water.

Although the reasons for the decrease in flexural, tensile and shear bond s~rength-enhancement, and other beneficial effects, after this effective time period has lapsed are not known, a possible explanation is that after this period, the STP begins to undergo a hydrolysis reaction and breaks down to its mono- and .

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a ~ s '092/04292 PCT/US91/06204 disodium precursors. Alternatively, the STP may undergo a polymerization reaction or structural transformation to a cyclic polyphosphate, such as sodium trimetaphosphate or sodium tetrametaphosphate.
Regardless of the mechanism responsible, after the effective period of time for addition of the a~ueous premix to the dry cement, aggregate, and optional fly ash has lapsed, it is believed that the cement compositions prepared begin to lose their enhanced properties according to the present invention.
While the cementitious compositions of the present invention can be formed without STP, it is believed that utilization of STP promotes a more thorough dis~rslon of the tar components within the matrix of the compositions. Furthermore, it is believed that the homogenous dispersion provided by the incorporation of STP into the aqueous premix contributes to the enhanced properties shown by the cured compositions. Accordingly, to obtain optimal increases in flexural, tensile and shear--bond strength, as well as the other beneficial properties of the compositians of the present invention, sufficient STP should be utilized in forming the aqueous premix, such that the preferred residual amounts disclosed herein remain after incorporation of the STP.
When the aqueous premix and dry cement, aggregate, and optional fly ash have been sufficiently mixed so as to form a homogenous mixture, the ~luid cementitious mixture or paste can then be poured into any suitable casing, shell, or mold, shaped according to the desired form of the article to be manufactured. The cementitious mixture is then allowed to harden until substantially solidified, preferably at room temperature -for at least 1 day.
The cementitious compositions of the present invention will exhibit comparable to significantly greater compression strength, and substantially greater -: . : . - . . .

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WO92/04292 PCT/US9~/06204 flexural, tensile and shear-bond strength, as measured in pounds per square inch (psi) of force applied, than standard concrete compositions prepared from the same amounts of ingredients but with water that is free of a tar component, its associated emulsifier systam and residual sodium tripolyphosphate. Specifically, the compression strength of the cementitious compositions or the present invention will range from comparabla values of those of standard concrete, up to substancially greater compressive strengths depending upon the amount of tar component and emulsifier system incorporated into the compositions of the present invention. Furthermore, the superior elastic properties of the pressnt compositions will be reflacted in an about 1-250 p~ C_i1_ greater fle~ural strength, and an about 2~200 percent greater tensile strength than those of standard concrete. More preferably, the compositions of the present invention will exhibit an about 20-200 percent, and most preferably 25-150 percent greater flexural strength than standard concrete. In addition, more preferred tensile strengths of 30-175 percent, and most preferably of 40-150 percent will be exhibited by the cementitious compositions of the present invention.
Also, the strength OI the adhesive bond between the cementitious compositions of the present invention and the subsurface over which they are laid will be reflected in a shear-bond strength which is from about 5-350 percent greater, preferably 10-250 percent, and most preferably about 20-200 percent greater than that observed between standard concrete adhered to an appropriate subsurface. In fact, the adhesive bond between the present compositions and an appropriate subsurface is such that ~he matrix of the cured cementitious composition will generally crack and break before the bond between the composi_ion and subsurface is overcome.
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2 ~ 9 V~92t04292 PCT/US91/06204 The superior flexural and tensile strength of the cementitious compositions of the present invention will further result in a highly wear resistant material.
For example, when compared to a standard concrete prepared from the same ingredients, but with water free of a tar component, its associated emulsifier system and residual sodium tripolyphosphate, the compositions of the present invention will exhibit significantly less ~reight 105s due to abrasion, and an impact strength 1~ which is abouL 10-500 percent greater, preferably 100-~00 perceTlt gr~ater, and most preferably 200-350 percent greater ~han ~hat of a standard concrete.
~he compositions of the present invention will - also bc , b~t2n-tially less permeable than comparable standard concretes. Thus, the cementitious compositions of the present invention are significantly more durable than standard concretes, based at least in part, on their enhanced ability to resist the transportation and retention of water and harmful soluble salts, such as chlorides and phosphates, through the matrix of the cured compositions. While not being held to a theory of i operation, one possible explanation for the decreased permeability of the compositions of the present invention is that dispersed pore structure of the cured compositions may be partly filled or sealed by the hydrbphobic, dispersed domains of tar component within the matrix of the cured compositions. Also, it is believed that--these same dispersed domains formed by the tar component tend to inhibit and limit the formation of microcracks in the cementitious matrix, there~y reducing the intake and transportation of water and soluble salts into the cured matrix of the composition.
Standard concretes often require the addition of various air entrainment additives to ensure that the cured product develops a proper pore structure. On tha other hand, latex modified concretes usually entrain substantially too much air, and accordingly must be .
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treated with anti-foaming agents. In contrast, the cementitious compositions of the present invention are self air-entraining, and form a more uniform dispersion of air throughout the cement paste. Specifically, the present compositions will entrain from about 4-15 percent airj preferably 5-12 percent, and most preferably 6-9 percent air without the incorporation of any additives.
In addition to superior physical properties, the cementitious compositions of the present invention are significantly easier to work with than many standard cement compositions. This enhanced workability provides cost advantages both with respect to significantly reduced labor costs, as well as a substantial rsductioQ
in wasted materials which must be replaced due -to improper working. Specifically, the compositions of the present invention do not "bleed" excess water to the surface when being mechanically screeted or hand troweled, and present a "cream" or "paste" which can be worked to a smooth finish substantially faster than standard concretes. In addition, the surface of the present compositions are less likely to be overworked than conventional concretes. In contrast, overworking of the surrace of standard concrete results in a nondurable, powdery cured surface which must be removed and replaced, thereby resulting in significantly increased labor and materials costs.
In addition to the properties discussed above, the cementitious compositions of the present invention may also exhibit substantially improved freeze/thaw, corrosion and skid resistance, as well as decreased drying shrinkage and incréased fatigue strength when compared to standard concrete compositions prepared from the same amounts of ingredients but with water that is free of a tar component, its associated emulsifier system and residual sodium tripolyphosphate.
Furthermore, it will be appreciated that while the ' ,' ~' ~' , 2~1169 `NO92/04292 PCT/US91/06~04 comparisons between the cementitious compositions of the present invention and standard concrete have been made with reference to the preferred compositions made with an aqueous premix of water, an emulsi~ied tar component and residual sodium tripolyphosphate, that the enhanced properties of the compositions of the present invention are maintained in a composition made with a premix lacking residual sodium tripolyphosphate, albeit at somewhat reduced levels over the properties exhibited by the preie rsd cGmposiLions.
; ~he inven-cion will be further described by reference LO Lhe followlng working example.

Exam~le ~our formul~tions OL ~ h9 C9mentitiOUS
compositions according to the present invention were prepared by mixing the following ingredients to make 6 yard batches. The amounts stated are per yard of the prepared compositions.
Formulation A:
513 pounds dry Portland cement (Northwestern States Portland Cement, Mason City, Iowa);
250 pounds water (wsll qatsr, ambient i 25 temperature, 100-240 ppm hardness) treated with a 50%
solids coal tar emulsion (a compositlon of 25 wt %
commercial coal tar, 25 wt % kaolin and bentonite clay, about 12 to 14 wt ~ of a mono, di or tri sulfonic acid derivative of a fatty acid or alcohol and a remainder of water, sold as "Twin Seal", St. Paul, Minnesota), such that 5.0 percent by weight of the aqueous premix, or 0.32 pexcent by weight of the total composition, is emulsified coal tar, and an excess of Na5P3OlO
(industrial-grade water treatment STP) to give a residual concentration of 20 ppm;
3054 pounds aggregate (1818 pounds 0.375 diameter washed stones; 1236 pounds fine sand); and .

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W092/04292 ` PCT/US91/06204 91 pounds fly ash (Class "C" fly ash from a coal-fired electric power plant).

` Formula~ion B:
: 5 513 pounds dry Portland cement;
250 pounds water treated with a 50% solids coal : tar emulsion (the "Twin Seal" Composition of Formulation.
A), such that 6.25 percent by weight of the aqueous premix, or 0.40 percent by weight of the total ~ 10 composition, is emulsified coal tar, and an excess of -~ Na5P3OIO co give a residual concentration of 20 ppm;
~ 305a pounds aggregate; and 91 pounds fly ash.
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Formulation C:
513 pounds dry Portland cement;
:~ 250 pounds water treated with a 50% solids coal tar emulsion (the;"Twin Seal" Composition of Formulation A), such that 8.33 percent by weight of the aqueous premix, or 0.54 percent by weight of the total composition, is emulsified coal tar, and an excess of Na5P3OiO to give a residual concentration of 20 ppm;
.: 3054 pounds aggregate; and 91 pounds fly ash.
.~ . Formulation D:
;~ 513 pounds dry Portland cement;
. . .250 pounds water treated with a 50% solids coal tar emulsion (the "Twin Seal" Composition of Formulation A), such that 12.5 percent by weight of the aqueou~
premix, or 0.80 percent by weight of the total : composition, is emulsified coal tar, and an excess of Na5P3O~O to give a residual concentration of 20 ppm;
3054 pounds aggregate; and 91 pounds fly ash.

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2~169 ~092/04292 PCT/US91/06204 Upon mixing, each of the formulations resulted in a homogen~us, gray amorphous cementitious material.
Where necessary, if any of the mixtures was drier or thicker than desired, 1-3 extra gallons of water was added to the entire 6 yard batch to improve the texture of the material as is a matter of course in the concrete industry.
Nhen wet, each of the rormulations behaved similarly, with very fgW percept1ble differences. In general, formulations A-3 took on an increasingly darker gray coloration, due to a progr~ssive increase in the tar contant from formulation A co D. Also, there was a progressive increase in the tackiness, and a decrease in the setti.ng timeC~ as rhe tar content o-E the formulations incraased. ~owever, all the formulations, regardless of the tar content, worked very quickly, with no water bleeding, and displayed the other enhanced workability characteristics described above.
Many of the formulations set to hard, durable ; 20 surface in a substantially shorter period of time than would be required for standard or latex-modified concrete. In fact, formulation D set so rapidly that it was capable of holding the weight of vehicles, without significant deformation, within four hours after being poured.
Each of the formulations was capable of sustaining significant deformation prior ~o cràcking and breaking. The flexural and tensile strengths of cured formulations A and B was further confirmed by the ability of thin slabs, varying between 1/4 to 2 inches in thickness, to withstand repeated exposure to 50,000+
pound trucks for over a year without substantial wear or breakage. In contrast, similar thickness slabs of a standard concrete mixture were destroyed by the pounding of the trucks in a matter of a few weeks.
The invention has been described with reference to various specific and preferred embodiments and `" ' ' .
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W O 92/04292 2 ~ P ~ /US~1/06204 : techniques. However, it should be understood that many variations may be made while remaining within the spirit and scope of the invsntion.

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Claims

WHAT IS CLAIMED IS:

1. A concrete composition formed from a combination of ingredients, comprising:
(a) about 0-85 weight percent aggregats;
(b) about 7-90 weight percent dry cement;
(c) about 0-50 weight percent fly ash; and (d) about 3-10 weight percent aqueous premix;
wherein the aqueous premix is a highly dispersed mixture of water, an emulsifier system and a tar component, the tar component is from about 0.1-25 weight percent of the aqueous premix, and the weight percents of ingredients (a)-(d) are relative to the total weight or the composition.

2. A composition of claim 1, wherein the aqueous premix further comprises from about 0.5 to 180 ppm of residual sodium tripolyphosphate.

3. A composition of claim 2, wherein the ingredient weight percentages are selected from about 30-85 percent aggregate, about 7-70 percent dry cement, about 1-30 percent fly ash and about 4-8 percent aqueous premix.

4. A composition of claim 2 wherein the aqueous premix contains from about 5 to 50 ppm of residual sodium tripolyphosphate.

5. A composition of claim 2 wherein the tar component is from about 5.0-12.5 weight percent of the aqueous premix.

.

6. The composition of claim 2 wherein the tar component is about 7.0-9.0 weight percent of the aqueous premix, and wherein the aqueous premix contains from about 18 to 21 ppm of residual sodium tripolyphosphate.

7. A composition of claim 6 which is formed from a combination of ingredients, comprising:
(a) about 75-80 weight percent of the aggregate;
(b) about 10-15 weight percent of the dry cement;
(c) about 2-3 weight percent of the fly ash; and (d) about 7-9 weight percent or the aqueous premix.

8. A composition of claim 2, wherein the dry cement is Portland cement.

9. A composition of claim 2, wherein the tar component comprises a bituminous material selected from the group consisting of petroleum asphalts, native asphalts, coal tars, oil tars, pitches, tall oil pitches and pyrogenous tar distillates of water-gas, wood, peat, bone, shale, rosin, fatty acid tars, and combinations thereof.

10. A composition of claim 2, wherein the emulsifier system comprises a primary emulsifying agent selected from the group consisting of an anionic emulsifier, a cationic emulsifier and a nonionic emulsifier.

11. A composition of claim 10, wherein the emulsifier system is a combination of a primary emulsifying agent and a secondary agent composed of a shearing-dispersing clay.

12. A composition of claim 11, wherein the combination further includes a mineral acid or base.

13. A composition of claim 9, wherein the tar component is coal tar.

14. A composition of claim 10, wherein the primary emulsifying agent is an anionic emulsifier of the formula: a mono-, di- or tri-sulphonate derivative of a fatty acid or alcohol.

15. A composition of claim 11, wherein the tar component and emulsifier system are a preformed material of from about 20-80 weight percent solids, about 0.05-25 weight percent primary emulsifying agent and 20-80 weight percent water, the solids comprising from about 30-70 weight percent coal tar and from about 30-70 weight percent secondary agent shearing-dispersing clay, based on the weight of the preformed material.

16. A composition of claim 15 wherein the preformed material is about 50 weight percent solids and about 50 weight percent water, the solids comprising about 50 weight percent coal tar and about 50 weight percent secondary agent shearing-dispersing clay.

17. A composition of claim 2 which exhibits a flexural strength which is within a range from comparable with to substantially stronger than the flexural strength of a concrete formed from the amounts of ingredients (a) to (c) of claim 1 and about 3-10 weight percent of potable water.

18. A composition of claim 2 which exhibits a tensile strength which is within a range from comparable with to substantially stronger than the tensile strength of a concrete formed from the amounts of ingredients (a) to (c) of claim 1 and about 3-10 weight percent of potable water.

19. A composition of claim 2 which exhibits a shear-bond strength between the composition and an appropriate substrate which is within a range from comparable with to substantially stronger than that between a concrete formed from the amounts of ingredients (a) to (c) of claim 1 and about 3-10 weight percent of potable water.

20. A composition of claim 2 which has an abrasion resistance that is within a range from comparable with to substantially greater than the abrasion resistance of a concrete formed from the amounts of ingredients (a) to (c) of claim 1 and about 3-10 weight percent of potable water.

21. A composition of claim 2 which exhibits an impact strength which is within in range from comparable with to substantially stronger than the impact strength of a concrete formed from the amount of ingredients (a) to (c) of claim 1 and about 3-10 weight percent of potable water.

22. A composition of claim 2 which has a permeability that is within a range from comparable with to substantially less than the permeability of a concrete formed from the amounts of ingredients (a) to (c) of claim 1 and about 3-10 weight percent of potable water.

23. A composition of claim 2 which is self air-entraining.

24. A hardened product produced by curing the cementitious composition of claim 2.

25. A premix for concrete formed from a combination of ingredients comprising:
(a) about 0.05-15 weight percent of an emulsifier system;
(b) about 0.10-25 weight percent of a tar component; and (c) about 65-99 weight percent water;
wherein the weight percents of the ingredients are relative to the total weight of the premix.

26. A premix of claim 25 further comprising from about 0.5 to 180 ppm of residual sodium tripolyphosphate.

27. A premix of claim 26 wherein the residual sodium tripolyphosphate is from about 5 to 50 ppm of the premix.

28. A premix of claim 26 wherein the residual sodium tripolyphosphate is from about 18-21 ppm of the premix.

29. A premix of claim 26 wherein the tar component is from about 5.0-12.5 weight percent of the premix.

30. A premix of claim 26 wherein the tar component is from about 7.0-9.0 weight percent of the premix.

31. A premix of claim 26 wherein the emulsifier system is from about 0.10-7.0 weight percent of the premix.

32. A premix of claim 26 wherein the emulsifier system is from about 0.25-3.0 weight percent of the premix.

33. A premix of claim 26, wherein the tar component comprises a bituminous material selected from the group consisting of petroleum asphalts, native asphalts, coal tars, oil tars, pitches, tall oil pitches and pyrogenous tar distillates of water-gas, wood, peat, bone, shale, rosin, fatty acid tars, and combinations thereof.

34. A premix of claim 33, wherein the tar component is coal tar.

35. A premix of claim 26, wherein the emulsifier system comprises a primary emulsifying agent selected from the group consisting of an anionic emulsifier, a cationic emulsifier and a nonionic emulsifier.

36. A premix of claim 35 wherein the primary emulsifying agent is an anionic emulsifier.

37. A premix of claim 35, wherein the emulsifier system is a combination of a primary emulsifying agent and a secondary emulsifying agent.

38. A premix of claim 37 which is formed from a combination of ingredients comprising:
(a) about 0.25-3.0 weight percent of the emulsifier system;
(b) about 7.0-9.0 weight percent of the tar component;
(c) about 65-99 weight percent water; and (d) about 18-21 ppm of residual sodium tripolyphosphate.

39. A process for manufacturing a high flexural-strength shaped article, comprising the steps of:
(a) mixing water with an emulsifier system and a tar component to produce an aqueous premix, wherein the tar component comprises from about 0.1-25 weight percent of the aqueous premix;
(b) forming a fluid cementitious mixture by mixing about 3-10 weight percent of the aqueous premix with about 0-85 weight percent aggregate, about 7-90 weight percent dry cement, and about 0-50 weight percent fly ash; and (c) pouring the fluid cementitious mixture into a casing so that the mixture hardens to form the shaped article.

40. A process of claim 39 further comprising adding to the mixture of step (a) an excess amount of sodium tripolyphosphate such that the aqueous premix contains from about 0.5 to 180 ppm residual sodium tripolyphosphate

41. A process of claim 40, wherein the cementitious mixture is free of one or both of the fly ash and the aggegate.

42. A process of claim 40, wherein the aqueous premix contains from about 15 to 22 ppm of residual sodium tripolyphosphate.

43. A process of claim 40, wherein the tar component comprises from about 5.0-12.5 weight percent of the aqueous premix.

44. A process for substantially increasing the flexural, tensile and shear-bond strength, while decreasing the water permeability of a cement composition, comprising forming the cement composition from a combination of dry cementitious ingredients and aqueous premix containing water, an emulsifier system and a tar component, wherein the tar component comprises from about 0.10 to 25.0 percent by weight of the aqueous premix, and wherein the cement composition exhibits substantially greater flexural, tensile and shear-bond strength, and substantially decreased water permeability than does a concrete formed from a combination of said dry cementitious ingredients and potable water.

45. A process according to claim 44 further comprising adding to the aqueous premix an excess of sodium tripolyphosphate to provide about 0.5-180 ppm residual sodium tripolyphosphate.

46. A cement composition which exhibits substantially greater flexural, tensile and shear-bond strength, and is less water permeable and porous formed according to the process of claim 45.

47. A shaped article manufactured by a process comprising the steps of:
(a) mixing water with an emulsifier system and a tar component to form an aqueous premix, wherein the tar component comprises from about 0.10 to 25.0 weight percent of the aqueous premix;
(b) forming a fluid cementitious mixture by mixing about 3-10 weight percent of the aqueous premix with about 0-85 weight percent aggregate, about 7-90 weight percent dry cement, and about 0-50 weight percent fly ash; and (c) pouring the fluid cementitious mixture into a casing so that the mixture hardens to form the shaped article.

48. A shaped article manufactured by the process of claim 47 further comprising adding to the aqueous premix or step (a) an excess amount of sodium tripolyphosphate such that the aqueous premix contains from about 0.5 to 180 ppm residual sodium tripolyphosphate.

49. A shaped article of claim 48, wherein the fluid cementitious mixture is free from one or both of the fly ash and the aggregate.