Prevention of slump loss in fresh concrete

A cement composition having improved slump loss characteristics comprising about 0.01 to 10 parts by weight of a powdery or granular iron or aluminum salt of a .beta.-naphthalenesulfonic acid-formaldehyde condensate having a particle diameter of from about 10 to 10,000 microns to 100 parts by weight of cement.

A concrete composition having improved slump loss characteristics comprising cement, aggregate and about 0.01 to 10 parts by weight, per 100 parts by weight of said cement, of a powdery or granular iron or aluminum salt of a .beta.-naphthalenesulfonic acid-formaldehyde condensate having a particle diameter of from about 10 to 10,000 microns.

A method for preventing slump loss in fresh concrete which comprises adding about 0.01 to 10 parts by weight, per 100 parts by weight of cement, of a powdery or granular iron or aluminum salt of a .beta.-naphthalenesulfonic acid-formaldehyde condensate having a particle diameter of from about 10 to 10,000 microns to a wet or dry concrete composition.

A method for preventing slump loss in fresh concrete which comprises adding a aqueous solution of an iron or aluminum salt of a .beta.-naphthalenesulfonic acid-formaldehyde condensate having a particle diameter of from about 10 to 10,000 microns to a wet or dry concrete composition in an amount to provide a final weight ratio of about 0.01 to 10 parts by weight of said salt per 100 parts by weight of cement.