Cleaning of equipment used with cementitious materials

Abstract

A composition that penetrates surfaces of equipment for use with an uncured cementitious material, such as uncured concrete includes an aqueous solution with colloidal silica. Pretreatment of a surface with such an aqueous solution may reduce or eliminate adhesion of uncured cementitious material to the surface. A composition that cleans hardened and/or cured cementitious material from the surfaces of such equipment also includes an aqueous composition with colloidal silica. Hardened and/or cured cementitious material may be removed from equipment surfaces by applying the hardened and/or cured cementitious material with the aqueous solution to soften the cementitious material and optionally abrading the softened cementitious material to mechanically remove the same from the equipment surfaces. Systems for removing hardened and/or cured cementitious material from the surfaces of equipment capable of use with uncured cementitious material include an aqueous solution with colloidal silica and a mechanical removal component.

What is claimed: 
     
         1 . A composition comprising a colloidal silica that softens hardened and/or cured cementitious material. 
     
     
         2 . The composition of  claim 1 , further comprising:
 a stabilizer.   
     
     
         3 . The composition of  claim 2 , wherein the stabilizer is on the colloidal silica. 
     
     
         4 . The composition of  claim 2 , wherein the stabilizer comprises a metal or a metal oxide. 
     
     
         5 . The composition of  claim 4 , wherein the stabilizer comprises aluminum or an aluminum oxide. 
     
     
         6 . A system for treating equipment used with a cementitious material, comprising:
 a composition comprising a colloidal silica that softens a hardened and/or cured cementitious material; and   a removal component that mechanically removes softened cementitious material from the equipment.   
     
     
         7 . The system of  claim 6 , wherein the removal component comprises gravel. 
     
     
         8 . The system of  claim 6 , wherein the removal component comprises:
 abrasive particles; and   an abrasion component that forces the abrasive particles against the softened cementitious material and/or the equipment.   
     
     
         9 . A method for removing cementitious material from equipment, comprising:
 applying a composition comprising a colloidal silica to hardened and/or cured cementitious material on the equipment; and   softening the hardened and/or cured cementitious material with the colloidal silica of the composition.   
     
     
         10 . The method of  claim 9 , further comprising:
 after applying the composition, mechanically removing softened cementitious material from the equipment.   
     
     
         11 . The method of  claim 10 , wherein mechanically removing the softened cementitious material from the equipment comprises abrading the softened cementitious material. 
     
     
         12 . The method of  claim 10 , wherein mechanically removing the softened cementitious material comprises impacting the softened cementitious material. 
     
     
         13 . The method of  claim 9 , wherein applying the composition comprises introducing the composition into a drum of a cement mixer. 
     
     
         14 . The method of  claim 13 , further comprising:
 rotating the drum with the composition in the drum.   
     
     
         15 . The method of  claim 13 , further comprising:
 introducing abrasives into the drum.   
     
     
         16 . The method of  claim 15 , further comprising:
 rotating the drum with the abrasives in the drum.   
     
     
         17 . The method of  claim 16 , wherein rotating the drum includes rotating the drum with the composition in the drum. 
     
     
         18 . The method of  claim 9 , wherein applying the composition comprises applying the composition to hardened and/or cured cementitious material on a surface of equipment capable of finishing a structure defined by the cementitious material. 
     
     
         19 . The method of  claim 18 , wherein applying the composition comprises applying the composition to hardened and/or cured cementitious material on a blade of a power trowel. 
     
     
         20 . The method of  claim 19 , wherein applying the composition to the hardened and/or cured cementitious material comprises applying the composition to cured concrete on the blade of the power trowel.