Patent ID: 6861459

Claim:
A method for making a dry cast cementitious article comprising: a. providing a mixture of hydraulic cement, water, coarse aggregate, fine aggregate, optionally a surface active agent/air entraining agent, and comprising an oligomeric dispersant, wherein the oligomeric dispersant comprises a reaction product of component A, optionally component B, and component C; wherein each component A is independently a nonpolymeric, multi-functional moiety or combination of moieties that adsorbs onto a cementitious particle, and contains at least one residue derived from a first component selected from the group consisting of phosphates, phosphonates, phosphinates, sulfates, sulfonates, sulfinates, borates, boronates, boroxines, phosphoramides, amines, amides, quaternary ammonium groups, carboxylic acids, carboxylic acid esters, alcohols, carbohydrates, phosphate esters of sugars, borate esters of sugars, sulfate esters of sugars, salts of any of the preceding moieties, and mixtures thereof; wherein component B is an optional moiety, where if present, each component B is independently a nonpolymeric moiety that is disposed between the component A moiety and the component C moiety, and is derived from a second component selected from the group consisting of linear saturated hydrocarbons, linear unsaturated hydrocarbons, saturated branched hydrocarbons, unsaturated branched hydrocarbons, alicyclic hydrocarbons, heterocyclic hydrocarbons, aryl, phosphoester, nitrogen containing compounds, and mixtures thereof; and wherein component C is at least one moiety that is a linear or branched water soluble, nonionic polymer substantially non-adsorbing to cement particles, and is selected from the group consisting of poly(oxyalkylene glycol), poly(oxyalkylene amine), poly(oxyalkylene diamine), monoalkoxy poly(oxyalkylene amine), monoaryloxy poly(oxyalkylene amine), monoalkoxy poly(oxyalkylene glycol), monoaryloxy poly(oxyalkylene glycol), poly(vinyl pyrrolidones), poly(methyl vinyl ethers), poly(ethylene imines), poly(acrylamides), polyoxazoles, and mixtures thereof; and b. forming the article from the mixture.