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

Abstract

A hydratable cement composition which will bond to both asphalt and cementitious substrates is supplied for the repair of various surfaces. The composition comprises of a combination of Portland cement, calcium sulfoaluminate cement or calcium aluminosilicate, and an alkali metal salt activated pozzolonic powder, wherein the Portland cement content of the hydratable portion of the composition is greater than 20%. The composition is free from latex bonding agents and calcium aluminate. The composition is mixed with water to form a typical cement, mortar, or concrete consistency, placed and allowed to cure. The result is a self-adhering patch to damaged surfaces. The hydratable cement composition may also be used to fabricate items of original construction by casting into molds or forms.

1 - 10 . (canceled) 
     
     
         11 . A cementitious composition comprising:
 a Portland cement;   calcium aluminosilicate;   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; and   an alkali salt;   wherein the Portland cement has a content of at least 20 percent based on the total weight of the non-Portland hydratable cement powder.   
     
     
         12 . The cementitious composition of  claim 11 , wherein the composition is free of latex bonding agents and calcium aluminate cement. 
     
     
         13 . The cementitious composition of  claim 11 , wherein the calcium aluminosilicate content is between 0.5 and 70 percent of the composition. 
     
     
         14 . The cementitious composition of  claim 11 , wherein the alkali salt content is between 0.1 and 10 percent of the composition. 
     
     
         15 . The cementitious composition of  claim 14 , wherein an alkali ion of the alkali salt is selected from a group comprising lithium, sodium, potassium, magnesium, and calcium. 
     
     
         16 . The cementitious composition of  claim 15 , wherein the alkali ion is in stoichiometric proportion with a hydrocarboxylic acid to form a pH neutral salt. 
     
     
         17 . The cementitious composition of  claim 16 , wherein the hydrocarboxylic acid is selected from a group comprising citric, lactic, and propionic. 
     
     
         18 . The cementitious composition of  claim 11 , wherein the pozzolanic powder is selected from a group comprising Class C Fly Ash, Class F Fly Ash, volcanic ash, diatomaceous earth, rice hull ash, opal, and a high free lime content powder. 
     
     
         19 . The cementitious composition of  claim 18 , wherein the high free lime content powder is selected from a group comprising lime kiln dust, cement kiln dust, slag, granulated blast furnace slag cement, and calcium oxide. 
     
     
         20 . The cementitious composition of  claim 11 , further comprising an additive selected from a group comprising retarders, shrinkage reducing agents, air entraining agents, aggregates, fillers, extruders, pigments, water reducers, fiber reinforcements, rheology modifiers, and set accelerators. 
     
     
         21 . The cementitious composition of  claim 20 , wherein the retarders are selected from a group comprising boric acid, sodium tetraborate, potassium tetraborate, boric oxide, sodium borate, potassium borate, borax pentahydrate, borax decahydrate, sulfate salts, sugars, sugar acids, and lignins; and
 wherein a total of the retarders is between 0.1 and 2.5 percent of the composition.   
     
     
         22 . The cementitious composition of  claim 20 , wherein the shrinkage reducing agents are configured to inhibit moisture egress during hydration. 
     
     
         23 . The cementitious composition of  claim 20 , wherein the shrinkage reducing agents are selected from a group comprising silica fume, liquid glycol, neopentyl glycol, a liquid glycol adsorbed on a surface of a solid carrier, calcium stearate, and magnesium stearate. 
     
     
         24 . The cementitious composition of  claim 20 , wherein the shrinkage reducing agents comprise a fine particulate metal powder selected from a group comprising alkali metals, alkali earth metals, aluminum, titanium, zinc, iron, magnesium, manganese, nickel, zirconium, and vanadium;
 wherein the fine particulate metal powder is configured to react with water to generate hydrogen or oxygen gas.   
     
     
         25 . The cementitious composition of  claim 20 , wherein the aggregates are selected from a group comprising pea gravel, river rock, sand, and crushed rock. 
     
     
         26 . The cementitious composition of  claim 20 , wherein the fillers are selected from a group comprising 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, and other fine ground types of stone. 
     
     
         27 . The cementitious composition of  claim 20 , wherein the pigments include iron oxide, titanium dioxide, or a combination thereof. 
     
     
         28 . The cementitious composition of  claim 20 , wherein the water reducers are selected from a group comprising lignin, melamine, naphthalene, polycarboxylate, and acrylic latex. 
     
     
         29 . The cementitious composition of  claim 20 , wherein the fiber reinforcements are selected from a group of fibers comprising nylon, polypropylene, Kevlar, steel, polyester, polyamide, acrylamide, basalt, e-glass, and s-glass; and
 wherein the fibers are between 0.125 and 2 inches in length.   
     
     
         30 . The cementitious composition of  claim 20 , wherein the rheology modifiers are selected from a group comprising lignin, melamine, naphthalene, polycarboxylate, acrylic latex, silica fume, fumed silica, precipitated silica, and polyethylene oxide; or
 wherein the set accelerators are selected from a group comprising lithium carbonate, lithium hydroxide monohydrate, lithium nitrate, lithium fluoride, lithium chloride, lithium borate, lithium acetate, lithium citrate, lithium lactate, and lithium gluconate.