System and method for increasing the bond strength between a structural material and its reinforcement

Abstract

A method of coating a reinforcing material, such as a metal, increases the adhesion between the material and a matrix, such as a cement-based mortar or concrete, in which the material is embedded. In one embodiment, a glass frit mixed with a refractory material, such as dry portland cement, is bonded, typically by heat, to the surface of the material. The reaction of the refractory component when the metal is embedded in fresh mortar or concrete prevents the formation of soft precipitates at the interface of the matrix and its reinforcement. One embodiment involves mixing portland cement Type I-II with a glass frit as a coating, coating a steel reinforcing rod and firing the coating to bond to the metal. The frit-refractory coating produces a strong bond between the metal reinforcement and its concrete or mortar matrix and may eliminate or significantly reduce the potential for corrosion of the reinforcement.

1 . A method for producing an enhanced reinforcing material for incorporating in an initially flowable matrix, comprising: 
 providing base reinforcing material;    selecting one or more flowable frits compatible with said matrix and said base reinforcing material;    selecting refractory material compatible with said matrix, said base reinforcing material and said frits;    mixing at least one said refractory material with at least one said frits to yield at least one coating;    preparing at least one surface of said base reinforcing material;    applying one or more of said coatings to said surfaces;    selecting at least one temperature regime for firing said coatings onto said base reinforcing material;    selecting at least one time regime for conducting said firing;    firing at least one said coatings onto said base reinforcing material at said selected temperature regime for said selected time regime; and    cooling said enhanced reinforcing material.    
   
   
       2 . The method of  claim 1  preparing said base reinforcing material by cleaning and degreasing said surfaces.  
   
   
       3 . The method of  claim 2  further comprising preparing said surfaces by: 
 cleaning with an alkaline cleaner;    then rinsing with water at temperature between about 45 and 60° C.;    then rinsing with water provided at ambient temperature;    then pickling in a dilute sulfuric acid solution of about 66-71° C.;    then rinsing in a dilute sulfuric acid solution provided at ambient temperature;    then depositing nickel via a nickel-containing solution held between about 60 and 82° C.;    then rinsing in a dilute sulfuric acid solution provided at ambient temperature; and    then neutralizing with a suitable fluid solution having a pH above 7.0.    
   
   
       4 . The method of  claim 1  providing said base reinforcing material selected from the group consisting of: metal fibers, metal rods, steel fibers, steel rods, metal alloy fibers, metal alloy rods, metal, metal alloys, steel, stainless steel, aluminum, copper, material plated with metal, and combinations thereof.  
   
   
       5 . The method of  claim 4  providing said steel, steel fibers and steel rods selected from the group consisting of: low-carbon steel; decarburized steel; interstitial-free steel, titanium-stabilized steel, and combinations thereof.  
   
   
       6 . The method of  claim 1  providing said initially flowable matrix as cement-based pastes selected from the group consisting of: portland cement-based mortars; portland cement-based concretes; phosphate-cement based mortars; phosphate-cement based concretes; 
 aluminum silicate cement-based mortars; aluminum silicate cement-based concretes, and combinations thereof.    
   
   
       7 . The method of  claim 1  providing said frit selected from the group consisting of: a ground glass, a ground glass slag, a frit suspended in a liquid, a glass frit suspended in a liquid, a frit suspended in a liquid incorporating a thickener, a powdered frit, a powdered glass frit, a frit containing transition metals, a frit containing cobalt, a frit containing nickel, an alkali-resistant glass frit, an alkali-resistant groundcoat enamel, and combinations thereof.  
   
   
       8 . The method of  claim 1  providing said refractory material from the group consisting of portland cement, slag, mica, quartz, inorganics having a melting point higher than said frits, and combinations thereof.  
   
   
       9 . The method of  claim 1  providing at least one said coatings as a mixture of at least one powdered glass frit and at least one dry refractory material.  
   
   
       10 . The method of  claim 9  providing at least one said coatings as a mixture of dry portland cement and a powdered alkali-resistant glass frit.  
   
   
       11 . The method of  claim 10  providing said powdered alkali-resistant glass frit in the form of at least one commercially available enamel groundcoat.  
   
   
       12 . The method of  claim 1  providing at least one said coatings as a mixture of at least one glass frit suspended in a liquid and at least one dry refractory material.  
   
   
       13 . The method of  claim 12  providing at least one said dry refractory material as dry portland cement and at least one said glass frit suspended in a liquid as an alkali-resistant glass frit.  
   
   
       14 . The method of  claim 13  providing said alkali-resistant glass frit suspended in a liquid as at least one commercially available enamel groundcoat.  
   
   
       15 . The method of  claim 1  providing at least one said coatings as a mix of a volume amount of said frits approximately equal to a volume amount of said refractory material, wherein each of said coatings comprises at least one said frit and at least one said refractory material.  
   
   
       16 . The method of  claim 1  providing at least one said coatings as a mixture of up to approximately 70% by volume of dry portland cement and as little as approximately 30% by volume of at least one powdered alkali-resistant glass frit.  
   
   
       17 . The method of  claim 1  applying said coating via a method from the group consisting of: spraying, dipping, brushing, flowing on, electrostatic spraying, rolling, and combinations thereof.  
   
   
       18 . The method of claim I selecting said temperature regime as inserting said coated reinforcing material into an oven pre-heated to the final temperature of said firing.  
   
   
       19 . The method of  claim 18  selecting said final temperature of said firing from about 500° C. to about 900° C.  
   
   
       20 . The method of  claim 18  selecting said final temperature of said firing from about 800° C. to about 875° C.  
   
   
       21 . The method of  claim 1  selecting said time regime as that time after inserting said glazed reinforcing material into an oven pre-heated to the final temperature of said firing until removal of said reinforcing material from said oven.  
   
   
       22 . The method of  claim 21  selecting said time of said firing from about two minutes to about 45 minutes.  
   
   
       23 . The method of claim of  claim 21  selecting said time of said firing from about 15 minutes to about 30 minutes.  
   
   
       24 . The method of  claim 1  accomplishing said cooling by removing said fired reinforcing material from said oven and permitting said reinforcing material to reach ambient temperature in ambient air.  
   
   
       25 . A method for improving a bond between enhanced reinforcing material and a matrix into which said enhanced reinforcing material is inserted prior to curing said matrix, comprising: 
 selecting at least one flowable frit compatible with said matrix and said reinforcing material;    selecting refractory material compatible with said matrix, said reinforcing material and said frits;    mixing said refractory material with said frits to yield at least one coating;    preparing at least one surface of said reinforcing material;    applying at least one said coating to said surfaces;    selecting a temperature regime for firing said coatings onto said reinforcing material;    selecting a time regime for conducting said firing;    firing said coatings onto said reinforcing material at said temperature regime for the duration of said time regime;    cooling said fired reinforcing material;    inserting said cooled reinforcing material into said matrix while said matrix is flowable, said cooled reinforcing material suitable to reinforce said matrix; and    curing said reinforced matrix.    
   
   
       26 . A method for reinforcing a matrix that is initially flowable by incorporating enhanced reinforcement material therein, comprising: 
 selecting at least one flowable frit compatible with said matrix and said reinforcing material;    selecting refractory material compatible with said matrix, said reinforcing material and said frits;    mixing said refractory material with said frits to yield at least one coating;    preparing at least one surface of said reinforcing material;    applying at least one said coating to said prepared surfaces;    selecting a temperature regime for firing said coatings onto said reinforcing material;    selecting a time regime for conducting said firing;    firing said coated reinforcing material at said temperature regime over said time regime;    cooling said fired and glazed reinforcing material;    inserting said cooled reinforcing material into said matrix while said matrix is flowable, said cooled reinforcing material suitable to reinforce said matrix; and    curing said reinforced matrix.    
   
   
       27 . A configuration affixed to reinforcing material for improving the bond between said reinforcing material and an initially flowable matrix incorporating said reinforcing material, comprising: 
 at least one flowable frit compatible with said matrix and said reinforcing material; and    refractory material compatible with said matrix, said reinforcing material and said frits,    wherein said refractory material is mixed with said frits to yield at least one coating, and    wherein at least one surface of said reinforcing material is prepared for accepting said coating, and    wherein at least one said coating is applied to said prepared surfaces, and    wherein said coating is fired on said reinforcing material during a pre-specified temperature regime and for a pre-specified time regime, and    wherein said fired reinforcing material is cooled, and    wherein said cooled reinforcing material is inserted into said matrix while said matrix is flowable, said cooled reinforcing material suitable to reinforce said matrix, and    wherein said reinforced matrix is cured.    
   
   
       28 . The configuration of  claim 27  in which said reinforcing material is material selected from the group consisting of: metal fibers, metal rods, steel fibers, steel rods, metal alloy fibers, metal alloy rods, metal, metal alloys, steel, stainless steel, aluminum, copper, material plated with metal, and combinations thereof.  
   
   
       29 . The configuration of  claim 28  in which said steel, steel fibers and steel rods are selected from the group consisting of: low-carbon steel; decarburized steel; interstitial-free steel, titanium-stabilized steel, and combinations thereof.  
   
   
       30 . The configuration of  claim 27  in which said initially flowable matrix comprises cement-based pastes selected from the group consisting of: portland cement-based mortars; portland cement-based concretes; phosphate-cement based mortars; phosphate-cement based concretes; aluminum silicate cement-based mortars; aluminum silicate cement-based concretes, and combinations thereof.  
   
   
       31 . The configuration of  claim 27  in which said frit is selected from the group consisting of: a ground glass, a ground glass slag, a frit suspended in a liquid, a glass frit suspended in a liquid, a frit suspended in a liquid incorporating a thickener, a powdered frit, a powdered glass frit, a frit containing transition metals, a frit containing cobalt, a frit containing nickel, an alkali-resistant glass frit, an alkali-resistant groundcoat enamel, and combinations thereof.  
   
   
       32 . The configuration of  claim 27  in which at least one said coatings is a mixture of at least one powdered glass frit and at least one dry refractory material.  
   
   
       33 . The configuration of  claim 27  in which at least one said coatings is a mixture of dry portland cement and a powdered alkali-resistant glass frit.  
   
   
       34 . The configuration of  claim 33  in which said powdered alkali-resistant glass frit is at least one commercially available enamel groundcoat.  
   
   
       35 . The configuration of  claim 27  in which at least one of said coatings is a mixture of at least one glass frit suspended in a liquid and at least one dry refractory material.  
   
   
       36 . The configuration of  claim 35  in which at least one said dry refractory material is dry portland cement and at least one said glass frit suspended in a liquid is an alkali-resistant glass frit.  
   
   
       37 . The configuration of  claim 36  in which said alkali-resistant glass frit suspended in a liquid is at least one commercially available enamel groundcoat.  
   
   
       38 . The configuration of  claim 27  in which at least one of said coatings is a mixture of a volume amount of said frits approximately equal to a volume amount of said refractory material, 
 wherein each of said coatings comprises at least one said frit and at least one said refractory material.    
   
   
       39 . The configuration of  claim 27  in which at least one of said coatings is a mixture of up to approximately 70% by volume of dry portland cement and as little as approximately 30% by volume of powdered alkali-resistant glass frit.  
   
   
       40 . The configuration of  claim 27  in which at least one said coating is applied via a method from the group consisting of: spraying, dipping, brushing, flowing on, electrostatic spraying, rolling, and combinations thereof.  
   
   
       41 . A reinforcing structure for improving the bonding of said reinforcing structure to an initially flowable matrix incorporating said reinforcing structure, comprising: 
 at least one base material having at least one surface suitable for coating;    at least one flowable frit compatible with said matrix and said base material; and    refractory material compatible with said matrix, said base material and said frits,    wherein said refractory material is mixed with said frits to yield at least one coating, and    wherein at least one surface of said base material is prepared for accepting said coating, and    wherein at least one said coating is applied to said prepared surfaces, and    wherein said coatings are fired on said surfaces at a pre-specified temperature regime over a pre-specified time regime, and    wherein said resultant coated reinforcing structure is cooled, and    wherein said resultant cooled reinforcing structure is inserted into said matrix while said matrix is flowable, and    wherein the resultant reinforced flowable matrix is cured.    
   
   
       42 . A method of enhancing bonding between surfaces of materials, comprising: 
 selecting at least one first and at least one second surfaces, at least one said first surface to be bonded to at least one said second surface;    selecting at least one first flowable fit compatible with said materials comprising said first surfaces;    selecting first refractory material compatible with at least said first surfaces and said first frits;    mixing said first refractory material with said first frits to yield at least one first coating;    preparing at least one first surface;    applying at least one said first coating to said first surfaces;    selecting at least one second flowable frit compatible with said materials comprising said second surfaces;    selecting second refractory material compatible with at least said second surfaces and said second frits;    mixing said second refractory material with said second frits to yield at least one second coating;    preparing at least one second surface;    applying at least one said second coating to said second surfaces;    selecting at least one temperature regime each for firing said first and second coatings onto said first and second surfaces, respectively;    selecting a time regime for conducting each of said firings of said first and second coatings;    firing said first and second coatings onto said first and second surfaces respectively at said temperature regimes for the duration of said time regimes;    cooling said fired first and second surfaces;    applying at least one grout to at least one said first and second fired surfaces;    bringing at least one said grouted surfaces in contact with at least one ungrouted surface to effect a bond between said first and second surfaces; and    curing said grout.    
   
   
       43 . The method of  claim 42  preparing said base reinforcing material by cleaning and degreasing said first and second surfaces.