Cementitious Composition With High Bond Strength To Both Asphalt And Cement Based Materials

Abstract

A cementitious composition includes a Portland cement and at least one non-Portland hydratable cement selected from the group consisting of calcium sulfoaluminate cement, a calcium aluminosilicate cement, and calcium aluminate cement, wherein the Portland cement has a content of at least 10 percent based on the total weight of the non-Portland hydratable cement powder, wherein the cementitious composition is free of latex bonding agents, and wherein the cementitious composition is bondable to asphalt. The cementitious composition may also include an aggregate in the form of asphalt millings.

Claims

1. A cementitious composition comprising: a Portland cement; and at least one non-Portland hydratable cement selected from the group consisting of calcium sulfoaluminate cement, a calcium aluminosilicate cement, and calcium aluminate cement; wherein the Portland cement has a content of at least 10 percent based on the total weight of the non-Portland hydratable cement powder; wherein the cementitious composition is free of latex bonding agents; and wherein the cementitious composition is bondable to asphalt.

2. The cementitious composition of claim 1, wherein the at least one non-Portland hydratable cement is between 0.5 to 70 percent by weight of the cementitious composition.

3. The cementitious composition of claim 1, further comprising an additive selected from the group consisting of retarders, shrinkage reducing agents, air entraining agents, aggregates, fillers, extenders, pigments, water reducers, fiber reinforcements, rheology modifiers, and set accelerators.

4. The cementitious composition of claim 3, wherein the cementitious composition includes the aggregates as the additive, and wherein the aggregates comprise asphalt millings.

5. The cementitious composition of claim 4, wherein a content of the asphalt millings is between 10 and 40 percent by weight of the cementitious composition.

6. The cementitious composition of claim 5, wherein the content of the asphalt millings is between 20 and 30 percent by weight of the cementitious composition.

7. The cementitious composition of claim 1, further comprising a hydrocarboxylic acid in stochiometric proportion with an alkali ion forming a water soluble salt, wherein the alkali ion is selected from a group consisting of lithium, sodium, potassium, magnesium, and calcium.

8. The cementitious composition of claim 7, wherein a content of the water soluble salt is between 0.1 and 10 percent by weight of the cementitious composition.

9. The cementitious composition of claim 7, wherein the hydrocarboxylic acid is selected from a group consisting of citric, lactic, and propionic.

10. A cementitious composition comprising: a non-Portland hydratable cement powder, which includes a pozzolonic powder and has a calcium content expressed as oxides of at least 15 weight percent based on the total weight percent of the non-Portland hydratable cement powder; at least two cements selected from the group consisting of a calcium aluminate cement, a calcium sulfoaluminate cement, and a calcium aluminosilicate cement; an alkali salt; and an aggregate in the form of asphalt millings; wherein the non-Portland hydratable cement powder has a content of at least 10 percent based on the total weight of the cementitious composition; wherein the cementitious composition is bondable to asphalt.

11. The cementitious composition of claim 10, wherein the cementitious composition is free of latex bonding agents and Portland cement.

12. The cementitious composition of claim 10, further comprising an additive selected from the group consisting of retarders, shrinkage reducing agents, air entraining agents, fillers, extenders, pigments, water reducers, fiber reinforcements, rheology modifiers, and set accelerators.

13. The cementitious composition of claim 10, wherein a content of the asphalt millings is up to approximately 30 percent by weight of the cementitious composition.

14. The cementitious composition of claim 13, wherein the content of the asphalt millings is between 20 and 30 percent by weight of the cementitious composition.

15. The cementitious composition of claim 10, wherein the at least two cements content is between 0.5 and 90 percent by weight of the cementitious composition.

16. The cementitious composition of claim 10, wherein the alkali salt content is between 0.1 and 10 percent by weight of the cementitious composition.

17. The cementitious composition of claim 10, wherein an alkali ion of the alkali salt is selected from the group consisting of lithium, sodium, potassium, magnesium, and calcium.

18. The cementitious composition of claim 17, wherein the alkali ion is in stoichiometric proportion with a hydrocarboxylic acid to form a pH neutral salt.

19. A cementitious composition comprising: at least two non-Portland hydratable cements selected from the group consisting of calcium sulfoaluminate cement, a calcium aluminosilicate cement, and calcium aluminate cement; and an aggregate in the form of asphalt millings; wherein a content of the at least two cements is between 0.5 and 90 percent by weight of the cementitious composition; wherein the cementitious composition is bondable to asphalt.

20. The cementitious composition of claim 19, wherein a content of the asphalt millings is between 10 and 40 percent by weight of the cementitious composition.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG. 1 shows a poor bond between a Portland concrete and an asphalt pavement.

[0052] FIG. 2 shows a separation of a concrete slab from a Portland concrete substrate.

[0053] FIG. 3 shows a bond between the present teaching and asphalt pavement.

[0054] FIG. 4 shows an enlarged image of FIG. 3.

[0055] FIG. 5 shows a bond between the present teaching and a Portland cement mortar.

[0056] FIG. 6 shows a bond between asphalt and Fly Ash with calcium sulfoaluminate.

[0057] FIG. 7 shows a bond between asphalt and Activated Fly Ash with calcium aluminate.

[0058] FIG. 8 shows a bond between asphalt and Activated Fly Ash with calcium sulfoaluminate.

[0059] FIG. 9 shows a bond between asphalt and Portland cement with calcium aluminate.

[0060] FIG. 10 shows a bond between asphalt and Portland cement with calcium aluminate and with calcium aluminosilicate.

[0061] FIG. 11 shows a bond between asphalt and Portland cement with Activated Fly Ash and with calcium aluminate.

[0062] FIG. 12 shows a bond between asphalt and Portland cement with Fly Ash and with calcium sulfoaluminate.

[0063] FIG. 13 shows a bond between asphalt and Portland cement with Activated Fly Ash.

DETAILED DESCRIPTION OF THE INVENTION

[0064] This application discloses several numerical ranges in the text. The numerical ranges disclosed inherently support any range or value within the disclosed numerical ranges even though a precise range limitation is not stated verbatim in the specification because this present teaching can be practiced throughout the disclosed numerical ranges.

[0065] For the purpose of this teaching, the phrase “substantially free” shall mean present in an amount of less than 1 weight percent based on the total weight of the referenced composition.

[0066] For the purpose of this teaching, the term “Activated Fly Ash” is defined as Fly Ash in the presence of a carboxylic acid salt.

[0067] In compliance with the statute, the present teachings have been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the present teachings are not limited to the specific features shown and described, since the systems and methods herein disclosed comprise preferred forms of putting the present teachings into effect.

[0068] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to a/an/the element, composition, apparatus, component, means, step, etc., are to be interpreted openly as referring to at least one instance of the element, composition, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. The use of “first,” “second,” etc. for different features/components of the present disclosure are only intended to distinguish the features/components from other similar features/components and not to impart any order or hierarchy to the features/components.

[0069] To aid the Patent Office and any readers of any patent issued on this application in interpreting the claims appended hereto, Applicant does not intend any of the appended claims or claim elements to invoke 35 U.S.C. 112(f) unless the words “means for” or “step for” are explicitly used in the particular claim.

[0070] The cementitious composition of one embodiment, according to the present teaching, includes, but is not limited to, a Portland cement, and at least one other cement from a group comprising, but not limited to, calcium sulfoaluminate cement, a calcium aluminosilicate cement, and calcium aluminate, wherein the Portland cement has a content of at least 20 percent based on the total weight of the non-Portland hydratable cement powder, wherein the cementitious composition bonds to asphalt.

[0071] The cementitious composition of one embodiment, according to the present teaching, includes, but is not limited to, a Portland cement, a calcium aluminate cement or a calcium aluminosilicate cement, a non-Portland hydratable cement powder, which includes a pozzolanic powder and has a calcium content expressed as oxides of at least 15 weight percent based on the total weight of the non-Portland hydratable cement powder, an alkali salt, and the Portland cement has a content of at least 20 percent based on the total weight of the non-Portland hydratable cement powder.

[0072] The cementitious composition of one embodiment, according to the present teaching, includes, but is not limited to, a non-Portland hydratable cement powder, which includes a pozzolanic powder and has a calcium content expressed as oxides of at least 15 weight percent based on the total weight percent of the non-Portland hydratable cement powder, an alkali salt, at least two cements from a group comprising, but not limited to, a calcium aluminate cement, a calcium sulfoaluminate cement, and a calcium aluminosilicate cement, wherein the non-Portland hydratable cement powder has a content of at least 10% on the total weight of the cementitious content, wherein the cementitious composition bonds to asphalt.

[0073] The cementitious composition of one embodiment, according to the present teaching, includes, but is not limited to, at least two cements from a group comprising, but not limited to, a calcium aluminate cement, a calcium sulfoaluminate cement, and a calcium aluminosilicate cement, wherein at least two cements comprise at least 10 percent of the composition, wherein the cementitious composition bonds to asphalt.

[0074] According to one embodiment the cementitious composition is substantially free of latex bonding agents.

[0075] According to one embodiment the cementitious composition is substantially free of bonding agents and Portland cement.

[0076] According to one embodiment the cementitious composition is substantially free of latex bonding agents, Portland cement, and a non-Portland hydratable cement powder selected from a group comprising, but not limited to, fly ash, rich hull ash, opal, diatomaceous earth volcanic ash, ground blast furnace slag cement, and high free lime content powder.

[0077] According to one embodiment the calcium sulfoaluminate cement, or calcium aluminosilicate, or calcium aluminate content is between 0.5 and 70 percent of the cementitious composition.

[0078] According to one embodiment the calcium aluminate, calcium sulfoaluminate, or calcium aluminosilicate content is between 0.5 and 90 percent of the composition.

[0079] According to one embodiment the pozzolanic powder is selected from a group consisting of Class C Fly Ash which was produced from the combustion of sub-bituminous or lignite coal, Class C Fly Ash which was produced by co-combustion of coal with clay and slag, Class F Fly Ash which was produced via co-combustion of coal with clay and slag, volcanic ash, diatomaceous earth, rice hull ash, opal, combinations thereof, or a blend of a high free lime content powder, and wherein the pozzolanic powder contains less than 15 percent calcium oxide and the overall calcium content of the calcium oxides is greater than 15 percent.

[0080] According to one embodiment the high free lime content powder is selected from a group consisting of lime kiln dust, cement kiln dust, slag, granulated blast furnace slag cement, calcium oxide, or combinations thereof.

[0081] According to one embodiment the alkali salt comprises either an alkali metal ion or an alkaline earth metal ion and comprises between 0.1 and 10 percent of said cementitious composition.

[0082] According to one embodiment the alkali metal ion is selected from a group consisting of lithium, sodium, or potassium and said alkaline earth metal ion is selected from a group consisting of magnesium or calcium, or in combinations thereof, in stoichiometric proportion with a hydrocarboxilic acid to form a pH neutral salt.

[0083] According to one embodiment the hydrocarboxilic acid is selected from a group consisting of citric, lactic, propionic based, or combinations thereof.

[0084] According to one embodiment the cementitious composition further comprises an additive selected from a group consisting of retarders, shrinkage reducing agents (SRA), air entraining agents (AEA), aggregates, fillers or extenders, pigments, water reducers, fiber reinforcements, rheology modifiers, set accelerators, or combinations thereof. For example, asphalt millings (i.e., the material that is surface ground off of existing pavement -evidenced by grooves in the road - prior to re-surfacing) may be included in the cementitious composition as an aggregate. Presently, the re-use of asphalt milling in new pavement is limited to 6%, The result is an ever-increasing stockpile which is counter to green environmental objectives. The asphalt millings may be between 10 and 40 percent by weight of the cementitious composition. In some embodiments, the asphalt millings may be between 20 and 30 percent by weight of the cementitious composition. In other embodiments, the asphalt millings may be up to approximately 40 percent by weight of the composition. In some embodiments, the asphalt millings may be up to approximately 35 percent by weight of the composition. In yet other embodiments, the asphalt millings may be up to approximately 30 percent by weight of the composition.

[0085] According to one embodiment the retarder is selected from a group consisting of boric acid, sodium tetraborate, potassium tetraborate, boric oxide, sodium borate, potassium borate, borax pentahydrate, borax decahydrate, sulfate salts, sugars, sugar acids, lignins, or combinations thereof in total consisting of between 0.1 and 2.5 percent of said cementitious composition.

[0086] According to one embodiment the shrinkage reducing agents functions by expanding to offset the autogenous shrinkage of the Portland and pozzolanic materials, including certain compounds which can form ettringite in-situ, and/or metal oxides whose hydrates have a lower specific gravity than their oxides.

[0087] According to one embodiment the ettringite formation during hydration is the product of various combinations of calcium sulfate cement (CS), calcium aluminate cement (CA), calcium aluminosilicate (CAS), calcium sulfoaluminate cement (CSA), calcium sulfate hemihydrate, calcium sulfate, and/or aluminum sulfate.

[0088] According to one embodiment the shrinkage reducing agent functions as an inhibitor to moisture egress during hydration and is selected from a group consisting of silica fume, liquid glycol, neopentyl glycol, a liquid glycol adsorbed on a surface of a solid carrier, calcium stearate, magnesium stearate, or a combination thereof.

[0089] According to one embodiment the shrinkage reducing agent further comprises a fine particulate metal powder selected from a group of alkali metals, alkali earth metals, aluminum, titanium, zinc, iron, magnesium, manganese, nickel, zirconium, vanadium, or combinations thereof which will react with water to generate hydrogen or oxygen gas.

[0090] According to one embodiment the aggregate is selected from a group consisting of asphalt millings, pea gravel, river rock, sand, crushed rock, or combinations thereof.

[0091] According to one embodiment the filler or extender is selected from a group consisting of ground glass, cenospheres, aluminum oxide, ground nutshells, ground rubber, fine ground hardened Portland cement, fine ground Portland concrete, find ground ceramic, fine ground clay brick, calcium carbonate, nephylene syenite, aluminum trihydrate, pumice, wollastonite, Class F fly ash, kaolin, meta-kaolin, silicon dioxide, dolomite, perlite, slate, other fine ground types of stone, asphalt millings, or combinations thereof.

[0092] According to one embodiment the pigment is selected from a group consisting of metal oxides including iron oxides, titanium dioxide, or combinations thereof.

[0093] According to one embodiment the water reducer is selected from a group consisting of lignin, melamine, naphthalene, polycarboxylate, acrylic latex, or combinations thereof.

[0094] According to one embodiment the fiber reinforcement is selected from a group of fibers consisting of nylon, polypropylene, Kevlar, steel, polyester, polyamide, acrylamide, basalt, e-glass, s-glass, or combinations thereof, in various lengths between 0.125 and 2 inches in length.

[0095] According to one embodiment the rheology modifier is selected from a group consisting of lignin, melamine, naphthalene, polycarboxylate, acrylic latex, silica fume, fumed silica, precipitated silica, polyethylene oxide, or combinations thereof.

[0096] According to one embodiment the set accelerator is selected from a group consisting of lithium carbonate, lithium hydroxide monohydrate, lithium nitrate, lithium fluoride, lithium chloride, lithium borate, lithium acetate, lithium citrate, lithium lactate, lithium gluconate, or combinations thereof.

[0097] According to one embodiment the Portland cement, non-Portland cement, calcium aluminate cements, calcium aluminosilicate cements, and calcium sulfoaluminate cement elements of the cementitious composition are free of the following materials: citric acid; lactic acid; alkali metal; metal carbonate; amine based activators; caustic compounds, such as sodium hydroxide, lithium hydroxide, and potassium hydroxide; geopolymers; non-aqueous thermoset organic polymers, such as polyurethane, epoxy, polyurea, and polyacrylates; bitumen; asphalt; asphalt polymer blends; chloride, iodide, bromide, and fluoride ions and salts; and combinations thereof.

[0098] According to one embodiment the cementitious composition can be used to repair roadways, sidewalks, foot paths, driveways, foundations, masonry work, joints for drains and pipes, water tightness of a structure, floors, roofs, beans, stairs, pillar, fencing posts, bridge, culverts, dams, tunnels, wells, water tanks, lighthouses, tennis courts, lamp posts, although not limited thereto.

[0099] According to one embodiment the cementitious composition bonds to asphalt.

[0100] Referring now to FIG. 1, the figure shows the lack of a good bond between a Portland concrete over asphalt pavement. FIG. 1 shows the current problem in cementitious compositions.

[0101] Referring now to FIG. 2, the figure shows the bond separation at the bottom of a concrete slab from a Portland concrete substrate.

[0102] Referring now to FIG. 3, the figure shows the cementitious composition according to the present teaching bonding to asphalt pavement in the upper left corner after outdoor exposure. The surface area was struck with repeated hammer blows in an unsuccessful attempt to delaminate the two dissimilar materials. There is a diagonal crack in the present teaching layer originating in the left center edge of the photograph. The crack was created by the sharp impact which caused the ejection of some aggregate in the asphalt layer. The interface bond remained intact demonstrating that the bond is stronger than either of the two dissimilar materials as evidence by failure within each material but not at the bond.

[0103] Referring now to FIG. 4, the figure shows an enlargement of the interface fracture surface section from FIG. 3. The figure shows the full contact between the two dissimilar materials even after the adjacent areas receiving fracture inducing forces.

[0104] Referring now to FIG. 5, the figure shows the cementitious composition according to the present teaching bonded to a Portland cement mortar after outdoor exposure. The area was struck with repeated hammer blows in an unsuccessful attempt to delaminate the two dissimilar materials. The present teaching is depicted in the upper portion of the photograph and the Portland mortar is in the lower portion of the photograph.

[0105] Referring now to FIG. 6, the figure shows the cementitious composition comprising Fly Ash and calcium sulfoaluminate bonding to asphalt.

[0106] Referring now to FIG. 7, the figure shows the cementitious composition comprising Activated Fly Ash and calcium aluminate bonding to asphalt.

[0107] Referring now to FIG. 8, the figure shows the cementitious composition comprising Activated Fly Ash and calcium sulfoaluminate bonding to asphalt.

[0108] Referring now to FIG. 9, the figure shows the cementitious composition comprising Portland cement and calcium aluminate bonding to asphalt.

[0109] Referring now to FIG. 10, the figure shows the cementitious composition comprising Portland cement, calcium aluminate, and calcium aluminosilicate bonding to asphalt.

[0110] Referring now to FIG. 11, the figure shows the cementitious composition comprising Portland cement, Activated Fly Ash, and calcium aluminate bonding to asphalt.

[0111] FIGS. 3, 4, and 5 show that the bond between the present teaching and substrates remained intact through several thermal and freeze and thaw cycles.

[0112] The above description is presented to enable a person skilled in the art to make and use the present teaching, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present teaching. Thus, this present teaching is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.