Composition for and method of pumping concrete

A method of pumping a concrete slurry through a pipe having an inlet end and an outlet end, said method comprising the steps of:

• providing a hopper;
• placing a fluid composition into said hopper;
• at least prior to said pumping of said concrete slurry, placing said hopper in fluid transmitting contact with a suction side of a concrete pump;
• pumping said fluid composition from said hopper with said pump into said inlet end of said pipe and through said pipe to said outlet end of said pipe;
• and, thereafter,
• adding said concrete slurry to said hopper to contact any of said fluid composition in said hopper whereby said concrete slurry is pumped into said inlet end of said pipe and through said pipe to said outlet end of said pipe;
• said fluid composition being comprised of an additive material mixed with water, said additive material being comprised of a water soluble, alkaline material selected from the group consisting of alkali metal hydroxides, carbonates, bicarbonates and mixtures thereof, and an organic polymeric material which disperses in the presence of water to produce an increase in viscosity of said water, which has a molecular weight of at least about 60,000, and which is selected from the group consisting of polysaccharides, polysaccharides modified with hydrophilic constituents, synthetic hydrophilic polymers and mixtures thereof;
• and
• said alkaline material being present in said additive in an amount in the range of from about 40 to about 99 parts per 100 parts by weight of said additive and said polymeric material being present in said additive in an amount in the range of from about 1 to about 60 parts per 100 parts by weight of said additive;
• and
• said water being present in said fluid composition in an amount sufficient to dissolve said alkaline material and disperse said polymeric material.

A method of pumping a flowable concrete slurry, said method comprising:

• A) providing mixed solid ingredients comprised of hydraulic cement and aggregate with water to make a concrete slurry;
• B) at least prior to pumping said concrete slurry, providing a fluid composition comprised of an additive mixed with water said additive being comprised of
• a water soluble, inorganic alkaline material selected from the group consisting of alkali metal hydroxides, carbonates, bicarbonates and mixtures thereof, and
• a solvatable, organic polymeric material selected from the group consisting of polysaccharides, polysaccharides modified with hydrophilic constituents, synthetic hydrophilic polymers and mixtures thereof
• wherein said water is present in said fluid composition in an amount sufficient to dissolve said alkaline material and permit dispersal of said polymeric material;
• C) pumping said fluid composition through a pump and conduit, wherein said conduit is lubricated by said fluid composition passing therethrough;
• thereafter
• D) pumping said concrete slurry through said pump and said conduit, with at least a portion of said slurry being in contact with at least a portion of said fluid composition, whereby said pumped fluid composition operates to improve pumpability and flowability of said concrete slurry and impede water loss from and solids separation within said concrete slurry;
• E) dispensing said fluid composition and said concrete slurry to a form;
• and
• F) permitting said concrete slurry to remain undisturbed in said form in the presence of said fluid composition for a time sufficient to produce set concrete having a compressive strength which is at least as great as the compressive strength of set concrete produced from said concrete slurry in the absence of said fluid composition.