Solidification and hardening accelerator for hydraulic binding agents and method for the production thereof

Abstract

A setting and curing accelerator for hydraulic binders comprises: Al 2 (SO 4 ) 3 aluminum sulfate, Al(OH) 3 aluminum hydroxide and mineral acid in aqueous solution. The setting and curing accelerator preferably comprises: 10-50% of Al 2 (SO 4 ) 3 aluminum sulfate, 5-30% of Al(OH) 3 aluminum hydroxide, 0.5-10% of a mineral acid in aqueous solution.

1 . A setting and curing accelerator for hydraulic binders, comprising: 
 Al 2 (SO 4 ) 3  aluminum sulfate, Al(OH) 3  aluminum hydroxide and mineral acid in aqueous solution.    
     
     
         2 . The setting and curing accelerator as claimed in  claim 1 , 
 characterized in that (in % by weight) the proportion of aluminum sulfate is 10-50% and/or the proportion of aluminum hydroxide is 5-30% and/or the proportion of mineral acid is 0.5-10%.    
     
     
         3 . The setting and curing accelerator as claimed in  claim 1 , characterized in that (in % by weight) the proportion of aluminum sulfate is 30-50% and/or the proportion of aluminum hydroxide is 5-20%.  
     
     
         4 . The setting and curing accelerator as claimed in  claim 1 , characterized in that (in % by weight) the proportion of aluminum sulfate is 40-45% and/or the proportion of aluminum hydroxide is 10-17% and/or the proportion of mineral acid is 0.5-8%.  
     
     
         5 . The setting and curing accelerator as claimed in  claim 1 , 
 characterized in that the mineral acid present comprises (in % by weight) 1-5% of H 3 PO 4  phosphoric acid and/or 0.5-3.0% of H 3 BO 3  boric acid.    
     
     
         6 . The setting and curing accelerator as claimed in  claim 1 , 
 characterized in that (in % by weight) 0-10% of alkanolamine and/or 0-5.0% of fluidizer and/or 0-20% of stabilizer are present.    
     
     
         7 . The setting and curing accelerator as claimed in  claim 1 , 
 characterized in that (in % by weight) 0-5% of alkanolamine and/or 0-10% of stabilizer and/or 0-3.0% of fluidizer are present.    
     
     
         8 . The setting and curing accelerator as claimed in  claim 6 , characterized in that the alkanolamine is a diethanolamine.  
     
     
         9 . The setting and curing accelerator as claimed in  claim 6 , characterized in that the stabilizer is a silica sol.  
     
     
         10 . The setting and curing accelerator as claimed in  claim 6 , characterized in that the fluidizer is a polycarboxylate.  
     
     
         11 . A process for producing a setting and curing accelerator, characterized in that a setting and curing accelerator as claimed in  claim 1  which is present in aqueous solution is dried, in particular by a spray drying process.  
     
     
         12 . The process for producing a setting and curing accelerator as claimed in  claim 11 , 
 characterized in that the dried mixture obtained is dissolved in water before addition to the hydraulic binder.    
     
     
         13 . A process for producing a setting and curing accelerator as claimed in any of  claim 1 , 
 characterized in that in the production of the aqueous solution and the addition of the components in the production of the solution, the solution is heated in a range from room temperature to 90° C.    
     
     
         14 . The process for producing a setting and curing accelerator as claimed in  claim 13 , 
 characterized in that the solution is heated to 50-80° C.    
     
     
         15 . A method of accelerating the setting and curing of hydraulic binders and also mortar or concrete produced therefrom, 
 characterized in that a setting and curing accelerator as claimed in  claim 1  is added in an amount of from 0.1 to 10% by weight to a mixture comprising hydraulic binders, with the percentages by weight being based on the weight of the hydraulic binder.    
     
     
         16 . The use of the setting and curing accelerator as claimed in  claim 1  in a spray concrete or spray mortar.