Abstract:
A cement formula including mono potassium phosphate, mono ammonium phosphate, magnesia, and fly ash exhibits rapid setting and high strength characteristics.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119 and applicable foreign and international law and incorporates in their entirety the following U.S. Provisional Patent Application Ser. No. 60/574,006 filed May 21, 2004. 
     This application also incorporates by reference in their entireties and for all purposes, the following U.S. patents: U.S. Pat. Nos. 3,285,758; 3,357,843; 3,879,209; 3,960,580; 4,059,455; 4,152,167; 4,394,174; 4,786,328; 4,836,854; 5,645,518; 5,830,815; 5,846,894; 6,133,498; 6,136,088; 6,153,809; 6,204,214; 6,518,212; and 6,569,263. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to cement, particularly cement that develops strength rapidly for patching or repairing cementitious surfaces or structures. 
     BACKGROUND OF THE INVENTION 
     There are many situations which require cement structure to be repaired. Most notably, roadways frequently wear and degrade resulting in holes, cracks, etc. 
     One problem with some cement repair formulas is that they take too long to develop sufficient strength to permit resumed use of the cement structure. This can be a major problem if the cement structure is, for example, a heavily traveled road. 
     Rapid setting formulas have been used in the past. However, these formulas suffer from a variety of problems. For example, rapid setting cement formulas sometimes use ammonium phosphate which produces noxious ammonia gas when mixed. 
     Some cement formulas set too fast, allowing insufficient time to work the material into the desired location and form. 
    
    
     DESCRIPTION 
     Improved cement formulations provide modern, all season, repair and anchoring materials in a single component, inorganic, high performance cement. Exemplary cement formulas adhere to concrete, masonry, metal, asphalt, and to itself, without the need of a bonding agent and may be used both inside and outside and in hot and cold temperatures. 
     The described formulas have been formulated for repair and anchoring of work that requires exceptional bonding, adhesion and strength. The formulas have been designed for jobs where availability of working time for the repair is limited or “down time” must be minimized. 
     A preferred formulation is shown below: 
     
       
         
               
               
             
               
               
               
             
           
               
                   
                   
               
               
                   
                 Neat Cement Formula: 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Hardburnt, high purity Magnesia (MgO) 
                 30.0% 
               
               
                   
                 Anhydrous Mono Potassium Phosphate 
                 24.0% 
               
               
                   
                 Mono Ammonium Phosphate 
                  6.0% 
               
               
                   
                 Fly Ash F 
                 40.4% 
               
               
                   
                   
                  100% 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
               
             
               
               
               
             
           
               
                   
                   
               
               
                   
                 Blended Cement ready to use: 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Hardburnt, high purity Magnesia (MgO) 
                 12.4% 
               
               
                   
                 Anhydrous Mono Potassium Phosphate 
                 10.0% 
               
               
                   
                 Mono Ammonium Phosphate 
                  2.5% 
               
               
                   
                 Fly Ash F 
                 16.5% 
               
               
                   
                 Silica Sand 16 mesh 
                 29.3% 
               
               
                   
                 Silica Sand 30 mesh 
                 29.3% 
               
               
                   
                   
                  100% 
               
               
                   
                   
               
             
          
         
       
     
     The total phosphate, including mono potassium phosphate (MKP) and mono ammonium phosphate (MAP), may be selected in the approximate range of 10% to 45% (w/w) of the total neat formula (excluding sand and water). For some applications the total phosphate amount should be in the range of 25% to 35% of the total neat formula. 
     The total phosphate component may be a mixture of MKP and MAP. MAP is important for increasing the reaction speed, providing faster setting and strength development. However, the MAP component should be minimized to avoid noxious ammonia odors. Preferably the MAP component is selected from the approximate range of 2% to 20% of the total neat formula. For some applications the MAP component should be in the range of 2% to 10%. 
     The following factors may affect the formulation. A formula incorporating MKP without MAP may be too slow to set (up to 45 minutes); and may show slow strength gain and low ultimate strength and low exotherm. Low amounts of MAP in addition to MKP showed surprising large gains in set speed and rapid strength development. High amounts of MAP, however, may cause the cement to set too fast and may produce an objectionable ammonia odor. 
     Another factor is the cost of MKP, which is much higher than MAP. This may influence the amount of MKP used. With MKP it is possible to use lower %&#39;s of a higher purity MgO, the next most costly ingredient, and we can use higher amounts of FAF, the least costly ingredient. Also, since FAF is considered a waste material, using higher %&#39;s contributes to the “green” (environmental) nature of the cement. 
     Advantages of improved cement formula, known as “Tectonite™ Cement” follow. Tectonite™ Cement allows the user sufficient working time (approximately 15 minutes at 72 F) without compromising high early strength development (approximately 3,000 psi in 30 minutes and 4,000 psi in 60 minutes). Tectonite™ Cement has a uniform color that cures closely to the color of Portland cement concrete. Tectonite™ Cement is smooth in texture in order to allow feathering in cosmetic repairs, while maintaining strength in structural repairs (minimum ¼″ thickness). Tectonite™ Cement requires less water than prior formulas. It is recommended that a ratio of 6 parts cement to 1 part water be used. The water cement mixture should be barely pourable. Water in excess of the recommended amount will weaken the cement&#39;s ultimate strength. 
     In cold weather applications it is recommended that for best results the repair area should be warmed as well as using warm mixing water. 
     Characteristics 
     High Strength—Tectonite™ achieves, in around a half an hour, compressive strengths attained by ordinary Portland cement in 28 days. 
     Fast Set—Tectonite™ sets in about 15 minutes (at 72 F) from the time of hydration and is traffic ready in about thirty minutes. 
     Tenacious Bond—Tectonite™ achieves, at a fraction of the cost of complicated epoxy cements, a chemical bond with materials to which it is applied. 
     Some Recommended Uses 
     
       
         
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 High Traffic Areas 
               
               
                   
                 Roadways - Concrete &amp; Asphalt (Easy color matching) 
               
               
                   
                 Potholes, Curbs, Sidewalks, Culverts, Pits, and Truck Docks 
               
               
                   
                 Bridges, Irrigation Structures, Tanks &amp; Dams 
               
               
                   
                 Walls, Seawalls, Runways, Aprons &amp; Parking Structures 
               
               
                   
                 Steps, Floors &amp; Corridors 
               
               
                   
                 Spillways &amp; Platforms Subject to High/Low Temperatures 
               
               
                   
                 Irregular Repairs - 
               
               
                   
                 Fast set often allows for hand held forms. 
               
               
                   
                 Broken Corners 
               
               
                   
                 Chipped Steps &amp; Abutments 
               
               
                   
                 Cracked and Spalled Areas 
               
               
                   
                 Free Form Contour Repair 
               
               
                   
                 Concave/Convex Surfaces 
               
               
                   
                 Difficult Verticals &amp; Angles 
               
               
                   
                 Anchoring &amp; Re-Anchoring 
               
               
                   
                 Iron &amp; Steel Anchoring 
               
               
                   
                 Easy Cleanup 
               
               
                   
                 Competitive with fast epoxies, less expensive 
               
               
                   
                 Guy Wires - Poles &amp; Posts 
               
               
                   
                 Signs - Parking Meters 
               
               
                   
                 Bolts - Frames &amp; Rails 
               
               
                   
                 Hand rails 
               
               
                   
                 Machinery Bases 
               
               
                   
                   
               
             
          
         
       
     
     Tectonite™ is fast setting. In hot weather, cold components will retard set time. In cold weather, warm components will accelerate set time. In normal temperatures (70–75 F), allow no more than 15 minutes for hydrating, mixing, placing, and finishing. Add only enough water to create a thick, barely pourable, mixture in accordance with recommendations. Prior to mixing large volumes, mix a cup-sized quantity to get a “feel” for consistency and set time. Store in a dry place. Moisture and/or high humidity will affect performance and reduce the one-year shelf life. 
     Area(s) to be repaired must be clean. Remove standing water. For best results, product should not be used for patches less than ¼ inch deep; for deep repairs, ⅜ inch non-calcareous aggregate at rate of 20–25 lbs. per 60 lbs. of cement may be added. Apply in multiple layers, allowing cement to cool between pours. In warm weather (80–110 F.°), cool repair area with cold water; in cold weather (30–45 F.°), heat repair area until warm to the touch. No moist cure is required. Air cure and protect from inclement weather until final set. 
     Mixing Ratios 
     It is recommended that a ratio of 6 parts cement to 1 part water be used, in order to produce a mix that is just barely pourable. Water in excess of the recommended amount may weaken the cement&#39;s ultimate strength. 
     Performance Data 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 ASTM C 109-93 Compressive 
                 2,787 PSI (19.2)/4,025 
               
               
                 Strength PSI. 
                 PSI (27.8)/ 
               
               
                 30 Minutes/1 Hour/28 days 
                 6,500 PSI (44.8) 
               
               
                 ASTM C 157, ASTM C 928-92a 
                 −0.002%, −0.007% 
               
               
                 Length Change 
               
               
                 28 Day Dry, 28 Day Wet 
               
               
                 ASTM C 78-84 Flexural Strength 
                 576 PSI (4.0), 626 PSI 
               
               
                 1 Hour, 1 Day, 28 Days 
                 (4.3), 760 PSI (5.2) 
               
               
                 ASTM C 882-87 Bond Strength with 
               
               
                 Portland Cement 
               
               
                 1 Day-Portland Cement Failed, Bond Held 
                 2,000 PSI (13.8) 
               
               
                 7 Day-Portland Cement Failed, Bond Held 
                 2,213 PSI (15.3) 
               
               
                 ASTM 666-90 Freeze/Thaw Resistance 
                 Freeze-thaw durable 
               
               
                 300 cycles 
               
               
                   
               
               
                 ( ) = MPa 
               
             
          
         
       
     
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Section I - Material Identification 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Trade/Material Name: 
                 Tectonite ™ (SF) Cement 
               
               
                   
                 Description: 
                 Magnesium Oxyphosphate Cement 
               
               
                   
                 Other Designations: 
                 Magnesium Oxide (Mag-Ox) 
               
               
                   
                 CAS: 
                 None assigned 
               
               
                   
                 Chemical Name: 
                 Magnesium Oxyphosphate Cement 
               
               
                   
                 Manufacturer: 
                 Tectonics International, per above 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
           
               
                   
               
               
                 Section II - Ingredients and Hazards 
               
             
          
           
               
                   
                   
                   
                 Exposure Limits 
               
               
                   
                 CAS 
                   
                 (Respirable Dust OHSA 
               
               
                 Ingredient Name 
                 Number 
                 Percent 
                 PEL) 
               
               
                   
               
               
                 Dead burned 
                 1309-48-4 
                 25–40 
                 10 mg/m 3   
               
               
                 magnesite 
               
               
                 Nitrogen 
                 10101-89-0 
                  5–12 
                 5 mg/m 3   
               
               
                 Phosphate 
                 7722-78-1 
                 10–15 
                 1 mg/m 3   
               
               
                 (AS P205) 
               
               
                 Phosphate (AS H 3   
                 7722-78-1 
                 10–15 
                 1 mg/m 3   
               
               
                 PO 4 ) 
               
               
                 Crystalline Quartz 
                 14808-60-1 
                 50–75 
                 .01 mg/m 3    
               
               
                 Fly Ash 
                 68131-74-8 
                 10–50 
                 5 mg/m 3   
               
               
                   
               
             
          
         
       
     
     This material contains less than 1% free silica. The respirable dust Permissible Exposure Limit (“PEL”) for this material would be: 3.3 mg/M 3  for total dust and 5 mg/M 3  for respirable dust. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 Section III - Physical Data 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Appearance &amp; Odor 
                 Granular Gray powder - no odor 
               
               
                 Boiling Point &amp; Evaporation Rate 
                 N/A 
               
               
                 Vapor Pressure 
                 N/A 
               
               
                 Specific Gravity, H 2 O = 1 
                 3.20–3.40 
               
               
                 Water Solubility (%) 
                 Nil 
               
               
                 Vapor Density, air = 1 
                 N/A 
               
               
                 Melting Point 
                 &gt;2,200° F. 
               
               
                 % Volatile by Volume 
                 0 
               
               
                   
               
             
          
         
       
     
     EXPERIMENT 
     Comparison of new formula vs. old formula (“neat”) exotherms: (Note: Neat cement with sand will show a little slower set time and lower exotherm.) 
     The cement formulas that were compared are shown below: 
     
       
         
               
             
               
               
               
             
               
             
               
               
               
             
           
               
                   
               
             
             
               
                 Old Formula 
               
             
          
           
               
                   
                   
                 % 
               
               
                   
                   
               
               
                   
                 MC-92 PV MgO 
                 57 
               
               
                   
                 Agrium 11-52-0 
                 26 
               
               
                   
                 MAP 
               
               
                   
                 Pozzolanic NW FAF 
                 17 
               
               
                   
                   
                  100% 
               
               
                   
                   
               
             
          
           
               
                 New Formula 
               
             
          
           
               
                   
                   
                 % 
               
               
                   
                   
               
               
                   
                 BayMag 96 SR MgO 
                 30 
               
               
                   
                 Rotem 0-52-34 MKP 
                 25 
               
               
                   
                 Agrium 11-52-0 MAP 
                  5 
               
               
                   
                 Pozzolanic NW FAF 
                 40 
               
               
                   
                   
                  100% 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
             
               
             
               
               
               
             
           
               
                   
               
             
             
               
                 Old Formula 
               
             
          
           
               
                   
                 Time 
                 Temp. 
               
               
                   
                   
               
               
                   
                  0 
                  71 F. 
               
               
                   
                  1 min. 
                  71 F. 
               
               
                   
                  2 
                  74 F. 
               
               
                   
                  3 
                  78 F. 
               
               
                   
                  4 
                  83 F. 
               
               
                   
                  5 
                  88 F. 
               
               
                   
                  5.5 
                  90 F. Set 
               
               
                   
                  6 
                  94 F. 
               
               
                   
                  7 
                 113 F. 
               
               
                   
                  8 
                 122 F. 
               
               
                   
                  9 
                 211 F. Max 
               
               
                   
                   
               
             
          
           
               
                 New Formula 
               
             
          
           
               
                   
                 Time 
                 Temp. 
               
               
                   
                   
               
               
                   
                  0 
                  71 F. 
               
               
                   
                  1 min. 
                  71 F. 
               
               
                   
                  2 
                  71 F. 
               
               
                   
                  3 
                  74 F. 
               
               
                   
                  4 
                  76 F. 
               
               
                   
                  5 
                  79 F. 
               
               
                   
                  6 
                  83 F. 
               
               
                   
                  7 
                  86 F. 
               
               
                   
                  8 
                  92 F. 
               
               
                   
                  9 
                 100 F. 
               
               
                   
                 10 
                 114 F. 
               
               
                   
                 11 
                 123 F. Set 
               
               
                   
                 12 
                 135 F. 
               
               
                   
                 13 
                 143 F. 
               
               
                   
                 14 
                 154 F. 
               
               
                   
                 15 
                 163 F. 
               
               
                   
                 16 
                 173 F. 
               
               
                   
                 17 
                 174 F. Max 
               
               
                   
                   
               
             
          
         
       
     
     The specific embodiments disclosed and illustrated herein should not be considered as limiting the scope of the invention, as understood by a person having ordinary skill in the art. Numerous variations are possible without falling outside the scope of the appended claims. The subject matter of the invention includes all novel and nonobvious combinations and subcombinations of the various elements, features, functions, and/or properties disclosed herein.