The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

A method of curing a low Ca/Mg cement composition is described that includes providing a predetermined quantity of the low Ca/Mg cement composition in uncured form; and reacting the uncured low Ca/Mg cement composition with a reagent chemical for a time sufficient to cure said cementitious material, wherein said reagent chemical is a compound synthesized from CO.sub.2 and comprises dicarboxylic acids, tricarboxylic acids, or alpha-hydroxycarboxylic acids.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

The present invention provides an admixture composition comprising a liquid suspension of colloidal silica, siloxane, and polycarboxylate polymer cement dispersant for enhancing early age strength, finishability, and other properties in hydratable cementitious compositions such as concrete (e.g., shotcrete). An inventive method involves mixing the components together in a specific sequence, thereby to obtain a stable liquid suspension. This attainment of a stable liquid suspension is surprising and unexpected because (i) the polycarboxylate polymer cement dispersant and siloxane components are incompatible and immiscible with one another; and (ii) that colloidal silica and siloxane compound are incompatible and immiscible with one another. Yet, the present inventors achieved an additive in the form of a stable liquid suspension which can be conveniently dosed into concretes and shotcrete mixtures, to enhance early age strength, and to improve workability and rheology in terms of finishability of concrete surfaces and improved rebound performance in shotcrete applications.

The present invention provides two-component compositions for making a waterproofing membrane comprising as component A) one or more acrylic aqueous emulsion copolymerization product (copolymer) of (i) from 60 to 89.9 wt. % of one or more nonionic (meth)acrylic monomers, preferably, butyl acrylate, methyl acrylate or ethylhexyl (meth)acrylate, (ii) from 10 to 40 wt. % of one or more vinyl aromatic monomers, (iii) from 0.1 to 2.0 wt. % of one or more amide functional acrylic monomer, and mixtures thereof with itaconic acid or methacrylic acid, wherein the emulsion copolymer has at least one residue of an ascorbic acid reducing agent and of t-butyl hydroperoxide and has less than 40 ppm or, preferably, less than 20 ppm, or more preferably, less than 10 ppm, of residual (meth)acrylamide.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

Plurality of granules comprising a ceramic core having an outer surface and a shell on and surrounding the core, wherein the shell comprises ceramic particles bound together with an inorganic binder, the inorganic binder comprising reaction product of at least alkali silicate and hardener, wherein the ceramic particles are present as greater than 50 percent by weight of the shell of the respective granule, based on the total weight of the shell of the respective granule, wherein the shell of each granule has a total porosity in a range from greater than 0 to 60 percent by volume, based on the total volume of the shell of the respective granule, wherein the shell of each granule has a volume of at least 40 volume percent, based on the total volume of the respective granule, and wherein the granules have a minimum Total Solar Reflectance of at least 0.7. The granules are useful, for example, as roofing granules.