Surface retarder coating compositions of the invention are based on the use of at least one non-Ordinary Portland Cement (non-OPC) binder and at least one OPC set retarder agent, which are provided in powder form that can be mixed with water at the construction site. The coating is applied onto the surface of a mould or formwork using roller or spray equipment, and concrete can then be cast within 30-60 minutes against the coating. The OPC set-retarding agent operates to retard setting of the concrete so that it can be de-moulded the next day and its surface can be removed using a high pressure water spray to reveal aggregate embedded beneath the removed surface.

A method of repairing a steel reinforced concrete structure (100) affected by chloride induced corrosion, comprising: subjecting the reinforced concrete structure (100) to an electrochemical treatment so as to enrich material (102, 120, 140) embedding the steel reinforcement (110) with chlorides originating from corrosion pits (112) in the steel reinforcement; and replacing the material (102, 120, 140) embedding the steel reinforcement (110), which has been enriched with chlorides during the electrochemical treatment, with a repair material (124) that is relatively poor in chlorides.

A method of repairing a steel reinforced concrete structure (100) affected by chloride induced corrosion, comprising: subjecting the reinforced concrete structure (100) to an electrochemical treatment so as to enrich material (102, 120, 140) embedding the steel reinforcement (110) with chlorides originating from corrosion pits (112) in the steel reinforcement; and replacing the material (102, 120, 140) embedding the steel reinforcement (110), which has been enriched with chlorides during the electrochemical treatment, with a repair material (124) that is relatively poor in chlorides.

Disclosed are surface retarder composition and method for etching cementitious materials which achieve a desirable light acid etch look without using muriatic (hydrochloric) acid or sand blasting, removing the human health and environmental concerns. Formulations in accordance with embodiments disclosed herein are easier to remove from formwork or molds after demolding than conventional retarder paints. Surface retarders prevent the hydration of cement particles, which allows the uncured layer of paste next to the form to be removed such as by washing with water or other fluids, or by brushing, revealing aggregates. Also disclosed are molded cement and concrete materials or articles exhibiting such light etch.

Disclosed are surface retarder composition and method for etching cementitious materials which achieve a desirable light acid etch look without using muriatic (hydrochloric) acid or sand blasting, removing the human health and environmental concerns. Formulations in accordance with embodiments disclosed herein are easier to remove from formwork or molds after demolding than conventional retarder paints. Surface retarders prevent the hydration of cement particles, which allows the uncured layer of paste next to the form to be removed such as by washing with water or other fluids, or by brushing, revealing aggregates. Also disclosed are molded cement and concrete materials or articles exhibiting such light etch.

An improved terrazzo process for applying terrazzo to an existing concrete surface comprising preparing the concrete surface, applying two layers of a primer agent, applying a terrazzo layer comprising calcium sulfoaluminate (CSA) cement, white milk glass, and one or more of broken mirrored glass and colored glass, cutting the terrazzo layer, applying a concrete densifier such that the concrete densifier penetrates into at least a portion of the concrete substrate, and grinding and polishing the densified terrazzo layer.

An improved terrazzo process for applying terrazzo to an existing concrete surface comprising preparing the concrete surface, applying two layers of a primer agent, applying a terrazzo layer comprising calcium sulfoaluminate (CSA) cement, white milk glass, and one or more of broken mirrored glass and colored glass, cutting the terrazzo layer, applying a concrete densifier such that the concrete densifier penetrates into at least a portion of the concrete substrate, and grinding and polishing the densified terrazzo layer.

Systems and methods for treating concrete, which includes the steps of wetting a surface of concrete with colloidal silica, allowing time for the colloidal silica to penetrate the concrete surface, and cutting the surface of the concrete with a bladed or segemented tool wherein the longitudinal blade or edge portion is positioned approximately at an angle between 30 degrees and 90 degrees relative to the surface of the concrete.

Systems and methods for treating concrete, which includes the steps of wetting a surface of concrete with colloidal silica, allowing time for the colloidal silica to penetrate the concrete surface, and cutting the surface of the concrete with a bladed or segemented tool wherein the longitudinal blade or edge portion is positioned approximately at an angle between 30 degrees and 90 degrees relative to the surface of the concrete.

Contemplated compositions and methods for protection of concrete and various other cementitious materials comprise a step of formation of a mesoporous polymeric network within the concrete or other cementitious material, wherein the network further includes a cationic component that forms a substantially insoluble precipitate upon reaction with sulfuric acid to so form a composite barrier against further attack by sulfuric acid.