Abstract: Set retarded cement compositions which are substantially non-thinning at high temperatures are provided. The compositions are comprised of hydraulic cement, sufficient water to form a pumpable slurry, a set retarder and a galactomannan gum which has been treated with a hydrophobing agent whereby the hydration rate of the gum is retarded at temperatures below about 120.degree. F. and at pH levels above about 10. The delayed hydration of the treated gum offsets the thinning of the cement compositions at temperatures above about 120.degree. F. Methods of cementing subterranean zones penetrated by well bores utilizing the cement compositions are also provided.

Abstract: A method of reclaiming leftover ready-mix concrete comprising the steps of:(1) retarding the hydration of the unused portion of concrete returned from a job site; and(2) after the desired retarded period adding a hydration acceleration agent to restore the concrete to a settable state.

Abstract: An additive combination for hydraulic cement compositions is provided which advantageously provides corrosion inhibition and set acceleration, in combination with a high level of fluidity and retention of fluidity over a desired period of time. The cement additive combination comprises an alkali or alkaline earth metal nitrite and a graft copolymer plasticizer comprising a polyether backbone and side chain polymers formed by polymerization of ethylenically unsaturated monomers.Fluid hydraulic cement compositions are further provided comprising these additive combinations.

Abstract: Coloring materials used in a process of dyeing concrete consist of pigment granules other than compacted or briquetted granules. The granules consist of one or more pigments, one or more binders for promoting the dispersing of the pigments in the concrete, and optional other additives. Such pigment granules, particularly bead granules, will easily dissolve in the concrete mixer and will be homogeneously dispersed in the concrete.